Note: Descriptions are shown in the official language in which they were submitted.
3~ 7 217 7 -15
BACKGROU~D OF THE INVENTIO~
The present invention relates to magnetic devices such
as saturable rèactors, transformers, choke coils, accelerator
cells, etc. for use in high-voltage pulse generating circults used
in pulse discharge gas lasers such as e~cimer lasers and copper
vapor lasers, accelerators, etc.
BRIEF DESCRIPTIO~ OF T~E DRAWINGS
Figure 1 is a cross-sectional view showing the saturable
reactor for high-voltage pulse generating apparatuses according to
one embodiment of the present invention;
Figure 2 is a perspective view showing one magnetic core
and an insulating coolant guide member used in the present
invention;
Figure 3 is a perspective view showing a magnetic core
and an insulating coolant guide member assembled together;
Fi.gure 4 is a cross-sectional view showing the saturable
reactor for high-voltage pulse generating apparatuses according to
another embodiment of the present invention;
Figure 5 is a cross-sectional view showing the magnetic
core assembly constituted by a plurality of wound magnetic cores
having different diameters according to a further embodiment of
the present invention;
Figure 6 is a cross-sectional view showing a wound
magnetic core constituting the magnetic core assembly shown in
Figure 5;
Figure 7 A is a front view showing a disc-shaped
insulating coolant guide member for preventing the contact of the
-- 1 --
~ 72177-15
magnetic core with the coaxial cylindrical conductor and for
guiding the coolant to flow in a radial direction of each magnetic
core according to the present invention;
Figure 7 B is a side view of the disc-shaped insulating
coolant guide member of Figure 7 A
Figure 8 is a cross-sectional view showing the
transformer for high-voltage pulse generating apparatuses
according to a further embodiment of the ~resent invention:
Figure 9 is a cross-sectional view showing the
transformer for high-voltage pulse generating apparatuses
according to a still further embodiment of the present invention;
Figure 10 :is a cross-sectional view showing the
accelerator cell according to a still further embodiment of the
present invention;
- Figure 11 is a cross-sectional view showing the
accelerator cell according to a still further embodiment of the
:~ present invention;
- Figure 12 is a cross-sectional view showing the
saturable reactor for high-voltage pulse generating apparatuses
according to a still furt'ner embodiment of the present invention;
Figure 13 is a cross-sectional view taken along the line
A-A in Figure 1;
Figure 14 is a cross-sectional view taken along the line
~-B in Figure l;
Figure 15 is a cross-sectional view showing the
saturable reactor for high-voltage pulse generatlng apparatuses
according to a still further embodiment of the present invention,
-- 2 --
~3~ 72177-15
Figure 16 is a cross-sectional view taken along the line
A-A in Figure 15;
Figure 17 is a cross-sectional view taken along the line
B-B in Figure 15;
Figure 18 is a cross-sectional view showing the
saturable reactor for high-voltage pulse generating apparatuses
according to a still further embodiment of the present invention;
Figure 19 is a cross-sectional view taken along the line
A-A in Figure 18:
Figure 20 is a cross-sectional view taken along the line
B-B in Figure 18;
Figure 21 is a partial cross-sectional view showing end
:~ portions of the magnetic core of the saturable reactor according
~: to the ~resent invention, which shows the direction of a coolant
flow;
Figure 22 is a cross-sectional view showing a saturable
: reactor according to a still further embodiment o~ the present
invention;
Figure 23 is a cross-sectional view taken along the line
A-A in Figure 22,
Figure 24 is a cross-sectional view taken along the line
B-B in Figure 22;
Figure 25 is a cross-sectional view taken along the line
C-C in Figure 22;
Figure 26 is a cross-sectional view taken along the
line D-D in Figure 22;
-- 3
~ 72177-15
Figure 27, on the same sheet as Figure 21, is a
cross-sectional view showing an exciting circuit Eor an excimer
laser which has a high-voltage pulse generating circuit for
; conducting magnetic pulse compression;
Figure 28 is a schematic view showing an exciting
circuit for an excimer laser which has a magnetic assist-type
high-voltage pulse generating circuit;
Figure 29 is a schematic view showing a high-voltage
pulse generating circuit for a linear induction accelerator;
Figure 30 is a cross-sectional view showing a
conventional saturable reactor for high-voltage pulse generating
apparatuses:
Figure 31 is a cross-sectional view showing a
conventional transformer for high-voltage pulse generating
apparatuses; and
Figure 32 is a cross-sectional view showing a
conventional accelerator cell.
One example of high-voltage pulse generating circuits
for excimer lasers, one type of pulse discharge gas laser, is
shown in Figure 27. The circuit of Figure 27 is called a magnetic
pulse compression circuit. DC voltage Vi is applied between
input terminals 201 and 202 with the polarity shown in the figure,
and during the period in which thyratron 204 is off, a main
capacitor 206 is charged to a voltage Vl of about several tens kV
with the polarity shown in -the figure. In this circuit, a voltage
V2 is applied between the terminals o~ a capacitor 207 after the
-- 4
~1?~3~ 72177-15
thyratron 204 is turned on, and a saturable reactor 208 functions
to compress the voltage V2 to a voltage Vo having a pulse width of
about 100 ns necessary for the oscillation of the excimer laser.
In this sense, this saturable reac-tor 208 may be called a mag~etic
switch. Incidentally, the pulse width of ~he voltage V2 applied
to both terminals of the capacitor 207 depends on a time constant
determined by capacitances of the capacitors 206 and 207 and the
inductance of an inductor 205. 203, 212 denote inductances for
charging the main capacitor 206, and 211 denotes electrodes for
the discharge of the e~c.imer laser.
In this circuit, since the pulse compression is
- 4a -
?3~ 72177-15
achieved by uslng the saturable reactor 208, peak losses generated
at the time of turn-on of the thyratron 204 and losses due to
after current and inverse current can be suppressed, thereby
contributing to high repetition rate, large output and long
service life of the excimer laser.
Figure 28 shows another example of high-voltage pulse
generating circuits for excimer lasers, whicll is called a magnetic
assist circuit. As in Figure 27, DC voltage Vi is applied
between input terminals 221 and 222 with the polarity shown in the
Eigure, and during the period in which thyratron 224 is off, a
main capacitor 226 is charged at a voltage Vl of about several
tens kV with the polarity shown in the figure. In this circult, a
saturable reactor 228 functions to delay the rise of the current
il, thereby decreasing switching losses generated at the time of
turn-on of the thyratron 224. Like the circuit shown in Figure
27, the circuit of Figure 28 contributes to achieving high
repetition rate, large output and long service life of the excimer
lasers.
As a further example of high-voltage pulse generating
circuits, a circuit used in a linear induction accelerator, which
is an accelerator of electron beams, etc., is shown in Figure 29.
As in Figure 27, DC voltage Vi is applied between input
terminals 241 and 242 with the polarity shown in the figure, and
during the period in which thyratron 244 is oEf, a main capacitor
246 is charged to a voltage Vl of about several tens kV with the
polarity shown in the figure. In this circuit, a transEormer 253
functions to increase the voltage, and by setting the number of
turns larger in a secondary
-- 5
winding 255 than in a primary winding 254, a voltage pulse
having a larger wave height than that of the input voltage V
can be generated between both terminals of the secondary
winding 255. Capacitors 247, 249 and saturable reactors 248,
256 constitute two steps of magnetic pulse compression
circuits, which usually function to compress the voltage V2
having a pulse width of several ~ between the terminals of the
capacitor 247 to a voltage V4 having a pulse width of about 100
ns or less between both terminals of a load 257. The load 257
is a conversion element called an accelerator cell for
accelerating electron beams, etc. The accelerator cell
functions like a kind of a transformer comprising a magnetic
core. Incidentally, the details of high-voltage pulse
generating apparatuses in a linear induction accelerator and
the accelerator cells are shown in, for instance, D.L. Brix,
S.A. Hawkins, S.E. Poor, L.I.. Reginato and M.W. Smith, "A
Multipurpose 5-MeV Linear Induction Accelerator," IEEE
Conference Record of 1984, Power Modulator Symposium, pp.
186-l90.
The magnetic device used for the above applications
is usually a wound magnetic core composed of an amorphous
magnetic ribbon and an insulation film or coating laminated
alternately to have a breakdown voltage of about several tens
kV or more. In the wound magnetic core, axial ends of the
2S insulation film extend from those of the amorphous magnetic
ribbon to prevent the insulation brea~down of the wound
magnetic core due to discharge on the axial end surfaces. ~hen
it is used at a high repetition rate of several hundred Hz or
-- .d' --
l~C~
morel the wound magnetic core is disposed such that it can be
Cc~ z 5 sec~ c~
cooled by a coolant such as ~3~ ~se~-a-i-E, a freon gas, an
-- insulating oil, etc.
Fig. 30 shows a saturable reactor capable of being
operated at a high repetition rate, as one example of magne-tic
devices for high-voltage pulse generating apparatuses. In this
figure, l denotes an input or output terminal, 2 a coaxial
cylindrical conductor having an outer wall 2a and an inner wall
2b, 3 an output or input terminal, 4 an inlet for a coolant, 5
an outlet for a coolant, 6 a plurality of magnetic cores, 7 an
insulating ring for fixing each magnetic core 6 to the inner or
outer wall of the coaxial cylindrical conductor 2, and ll an
insulating seal member for providing insulation between the
input and output terminals l, 3 and for sealing a cavity
defined by the inner and outer walls 2a, 2b of the coaxial
cylindrical conductor 2. In this saturable reactor, the
magnetic cores 6 are cooled by circulating a cooling oil by a
pump (not shown).
Fig. 31 shows a transformer having a turn ratio of
l:l as an example of transformers used in high-voltage pulse
generating circuits. In this figure, 261 denotes a terminal
common to primary and secondary windings of the transformer.
One turn of the primary winding is constituted by the terminal
261, a cylindrical conductor 262, a rod conductor 263, a
disc-shaped conductor 264, a rod conductor 265 and a primary
winding end 266. On the other hand, one turn of the secondary
winding is constituted by the terminal 261, the cylindrical
conductor 262, a rod conductor 267, a disc-shaped conductor
_ ~ _
'
S~
268, a rod conductor 269 and a secondary winding end 270.
Incidentally, a plurality of the magnetic cores 271 are fixed
to the cylindrical conductor 262 by an insulating ring 272. In
this transformer, the magnetic cores 271 are cooled by
immersing the entire transformer in an oi] bath.
Fig. 32 shows the structure of an accelerator cell
used in the linear induction accelerator. An input winding
having a turn number of 1 is constltuted by terminals 281a,
281b, a coaxial cylindrical conductor 282 and terminals 283a,
283b, and an output winding having a turn number of 1 is
constituted by terminals 291a, 291b, a coaxial cylindrical
conductor 292 and a terminal 293. Incidentally, the terminals
283a and 283b and the terminals 291a and 291b are respectively
connected electrically. A plurality of magnetic cores 286 are
fixed to the coaxial cylindrical conductor 282 by insulating
rings 287. The magnetic cores 286 are cooled by a cooling oil
flowing from an inlet 296 to an outlet 297 in the direction
shown by the arrow. 294 denotes a conical insulating seal
member for sealing the high-voltage pulse generating circuit of
the accelerator cell filled with an insulating oil from a space
in which electron beams move.
In the above magnetic cores for high-voltage pulse
generating apparatuses cooled by an insulating oil, heat spots
tend to be generated inside the magnetic cores by magnetic core
losses when a repetition rate is increased, for instance, to 1
kHz or more. As a result, the characteristics of the magnetic
cores are deteriorated in a short period of time after starting
the operation. In an extreme case, the magnetic properties of
.
_ ,~ _
5~
72177-15
the magnetic cores at heat spots are drastically deteriorated, and
their initial properties cannot be recovered af-ter res-tart of the
operation. Such deterioration of the magnetic properties due to
the heat spots is remarkable particularly when the amorphous
magnetic ribbon is used for constituting the magnetic cores.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a
magnetic device for high~vol-tage pulse generating apparatuses in
which temperature increase is suppressed, thereby preventing the
generation of heat spots in the magnetic cores.
Thus, the magnetic device for high-voltage pulse
generating apparatuses according to one embodiment of the
invention comprises (a) at least one cylindrical conductor for
~ defining a cavity, said cylindrical conductor being provided with
; input and output terminals and an inlet and an outlet for a
coolant; (b) at least one sealing member fixed to said
cylindrical conductor; (c) a plurality of wound magnetic cores
each composed of a magnetic ribbon laminated wit an insulating
layer, said wound magnetic cores being fixed to said cylindrical
conductor with such an interval as to provide a certain space
between the adjacent wound magnetic cores; and (d) an outer ring
member disposed between each of said magnetic cores and
cylindrical conductor and having at least one path for permitting
said coolant to flow therethrough, whereby said coolant f~ows in a
radial or circumferential direction of each wound magnetic core in
each space between the adjacent wound magnetic cores.
~ 72177-15
The magnetic device for high-voltage pulse generating
apparatuses according to another embodiment of the present
invention comprises (a) a coaxial cylindrical conductor having an
inner cylindrical wall and an outer cylindrical wall for defining
a cavity therebetween, the coaxial cylindrical conductor being
provided with input and output terminals ancl an inlet and an
outlet for a coolant, (b) an insulating sealing member fixed to
the coaxial cylindrical conductor for sealing the cavity' and (c)
a plurality of wound magnetic cores each composed of a magnetic
ribbon laminated with an insulating layer, the wound magnetic core
being fixed in the cavity via outer insulating ring members and
inner insulating riny members with such an interval as to provide
a certain space between the adjacent wound magnetic cores, the
inner and outer insulating ring members alternately having paths
for permitting the coolant to flow therethrough, whereby the
coolant flows in a
- 9a -
i3~
radial direction of each wound magnetic core in each space
between the adjacent wound magnetic cores.
The magnetic device for high-voltage pulse generating
apparatuses according to another embodiment of the present
invention comprises ta) a coaxial cylindrical conductor having
an inner cylindrical wall and an outer cylindrical wall for
defining a cavity therebetween, the coaxial cylindrical
conductor being provided with input and output terminals and an
inlet and an outlet for a coolant: (b) an insu1ating seali~g
member fixed to the coaxial cyli~drical conductor ~or sealing
the ~avity ~o) a plurality of magneti~ core assemblies each
composed of a plurality of wound magnetic cores disposed
radially wlth a certain gap between radially adjacent wound
magnetiC cores~ each of the wound magnetic cores being co~posed
of a magnetic ribbon laminated with an insulating layer, and
the magnetiC ~ore assemblies being fixed in the cavity with
such an interval as to provide a certain space between axially
adjacent magnetic core assemblies; and (d) a plurality of
~disc-shaped insulating coolant guide members each having a
20 plurality of apertures, the apertures being positioned between
radially adjacent gaps of the magnetic core assemblies, whereby
the coolant flows in a radial direction of each wound magnetic
core in each space betweèn the axially adjacent magnetic core
assemblies.
~he magnetic device for high-voltage pulse generating
apparatuses according to a further embodiment of the present
invention comprises (a) a coaxial cylindrical conductor having
an inner cylindrical wall and an outer cylindrical wall for
,,~ _
/~
5~:33
defining a cavity therebetween, the coaxial cylindrical
conductor being provided with input and output terminals and an
inlet and an outlet for a coolant; (b) an insulating sealing
member fixed to the coaxial cylindrical conductor for sealing
the cavity; (c) a plurality of wound magnetic cores each
composed of a magnetic ribbon laminated with an insulating
layer, the wound magnetic cores being fixed in the cavity via
outer insulating ring members and inner insulating ring members
with such an interval as to provide a certain space between the
adjacent wound magnetic cores, the inner and outer insulating
ring members alternately having paths for permitting the
coolant to flow therethrough; and (d) inner and outer
insulating coolant guide members disposed in each space between
the adjacent wound magnetic cores, each of the inner and outer
insulating coolant guide members having a notch for permitting
the coolant to pass therethrough, the notches of the inner and
outer insulating coolant guide members being located in each
: space substantially at diametrically opposite positions,
whereby the coolant flows along the circumferential direction
of each wound magnetic core.
The magnetic device for high-voltage pulse generating
apparatuses according to a still further embodiment of the
present invention comprises (a) inner and outer cylindrical
conductors disposed coaxially for defining a cavity
therebetween7 said outer cylindrical conductor being provided
with input and output terminals and an inlet and an outlet for
a coolant; (b) a pair of insulating sealing members fixed to
said inner and outer cylindrical conductors for sealing said
0,
3S3~
cavity; (c) a plurality of wound magnetic cores each composed
of a magnetic ribbon laminated with an insulating layer, said
wound magnetic cores being fixed in said cavity via outer
insulating ring members and inner insulating ring members with
such an interval as to provide a certain space between the
adjacent wound magnetic cores, said inner and outer insulating
ring members alternately having paths for permitting said
coolant to flow therethrough; and (d) inner and outer
insulating coolant guide members disposed in each space between
the adjacent wound magnetic cores, each of said inner and outer
insulating coolant guide members having a notch for permitting
said coolant to pass therethrough, said notches of the inner
and outer insulating coolant guide members being located in
each space substantially at diametrically opposite positions,
whereby said coolant flows along the circumferential direction
of each wound magnetic core.
The magnetic device for high-voltage pulse generating
apparatuses according to a still further embodiment of the
present invention comprises (a) a cylindrical casing provided
: 20 with an inlet and an outlet for a coolant; (b) a pair of
insulating plates fixed to both ends of the cylindrical casing
for defining a cavity, each of the insulating plates being
provided with at least one terminal for a winding; (c) an inner
insulating cylindrical member extending axially in the
cylindrical casing and having a plurality of holes extending
axially; (d) a plurality of wound magnetic cores each composed
of a magnetic ribbon laminated with an insulating layer, the
wound magnetic cores being fixed to the inner insulating
1~
L~3~
,, .
72177-15
cylindrical member with a certain space between the adjacent wound
magnetic cores; (e) a plurality of outer insulating ring members
each disposed between the wound magnetic core and the cylindrical
conductor, the outer insulating ring members being provided with a
plurality of holes extending axially; (f3 a plurality of outer
insulating ring spacers each having a pair of notches positioned
diametrically opposite to each other; and (g) at least one winding
having a plurality of turns extending through the holes of the
inner insulating cylindrical member and the outer insulating ring
members, whereby a coolant in-troduced into the cavity through the
i.nlet flows circumferentially from one notch to the other notch of
the outer insulating ring spacer in each space between the
adjacent wound magnetic cores.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows a saturable reactor as a magnetic device
'
j3~
for high-voltage pulse generating apparatuses according to one
embodiment of the present invention. In Fig. 1, 1 denotes an
input or output terminal, 2 a coaxial cylindrical conductor
having an outer wall 2a, an inner wall 2b and an end wall 2c
for defining a cavity, 3 an output or input terminal, 4 an
inlet for a coolant, 5 an outlet for a coolant, 6 a plurality
of wound magnetic cores each constituted by a Co-base amorphous
magnetic ribbon, for instance, and an insulating tape such as a
,i polyethylene terephthalate film tape such as Mylar film tape, 7
and 8 insulating ring members for fixing the magnetic core 6
and shutting the flow of a coolant, 9 and lO insulating coolant
guide ring members for keeping the adjacent magnetic cores
separate from each other and for permitting the coolant to pass
therethrough such that the end surfaces of the magnetic cores
can be uniformly cooled by the coolant, and 11 an insulating
seal member for electrically insulating the input and output
terminals 1, 3 and for sealing the cavity defined by the inner,
~ outer and end walls 2a-2c of the coaxial cylindrical conductor
: 2. In this saturable reactor, a coolant such as a cooling oil
is introduced into the cavity of the coaxial cylindrical
conductor through the inlet 4, and it flows in the cavity along
the course of ~ ~ . While uniformly
: cooling the end surfaces of each magnetic core 6, the coolant
is discharged through the outlet 5 and recycled by a pump (not
shown).
In the present invention, the end surfaces of the
magnetic cores 6 are uniformly cooled. In the case of a wound
magnetic core, particularly an interlaminar insulation-type
k
- 14 --
3~;ii3~3
72177-15
wound magnetic core as in this embodiment, the thermal coefficient
of the magnetic core is much smaller in the radial direction of
the magnetic core than in the axial direction of the magnetic
core. Accordingly, to increase cooling efficiency, it is
important to uniformly cool the end surfaces of each magnetic
core.
Figure 2 shows one example of an insulating coolant
guide ring member 10 disposed between the adjacent magnetic cores
6 for uniformly cooling the end surfaces oE each magnetic core 6.
The magnetic core 6 and the insulating coolant guide ring member
10 are assembled together in the saturable reactor of Figure 1 as
shown in Figure 3. Pro~ections lOa of the insulating coolant
~ guide ring member 10 are directed opposite to the inlet 4, namely
; toward the outlet 5 in Figure 1. In other words~ the insulating
coolant guide ring member 10 has a plurality of notches lOb which
provide a plurality of spaces or gaps when assembled with the
magnetic core 6, thereby permitting the coolant to pass
therethrough. Accordingly, the cooling oil flows as shown by the
arrow in Figure 3 from the inside of the magnetic core 6 to the
outside of the magnetic core 6 and then along the circumferential
surface of the magnetic core 6. Since the inner surface of the
magnetic core 6 is fixed to the insulating ring member 7, the
cooling oil does not pass through the inside of the magnetic core
6. Thus, the cooling oil flows in the radial direction of the
magnetic core G from inside to outside, and the end surfaces of
each magnetic core 6 are uniformly cooled. The cooling oil then
flows over the circumferential surface of each magnetic core 6
- 15 -
~ 2~ 3~and enters in-to a subse~uent cavity defined by the adjacent
magnetic cores 6, 6 and the coaxial cy~indrical conductor 2.
The cooling oil then flows from the outside toward the inside
of the magnetic core 6. This process is ~ ~ ~ as shown in
Fig. 1.
The insulating coolant guide ring member 9 also has
essentially the same shape as the insulati.ng coolant guide ring
member 10 shown in Fig. 2, and the insulating coolant guide
ring member 9 has an outer diameter slightly larger than the
inner diameter of the magnetic core 6 and an inner diameter
slightly smaller than the inner diameter of the magnetic core
6. The projections of the insulating coolant guide ring member
9 are directed opposite to the inlet 4, namely toward the
outlet 5 in Fig. 1. Incidentally, since the outer surface of
the magnetic core 6 is fixed to the insulating ring member 8,
the cooling oil does not flow along the outer surface of the
magnetic core 6. Because of this structure, the cooling oil
; can flow through notches defined by a plurality of projections,
and the cooling oil flows from the outer side toward the inner
side of the magnetic core 6 in a cavity, thereby uniformly
cooling the end surfaces of the magnetic cores 6. The cooling
oil then flows along the inner surface of the magnetic core 6
and then from inside to outside in a subsequent space. This
flow of the cooling oil is shown by 3 ~ ~ in Fig. 1.
With a silicone oil having a viscosity of 5 mm2/S as
cc-~e,ss;O~ 0
a cooling oil, the variation of~a co~ s~i~-~a-t--i~ with time
l,.`~
was measured on the saturable reactor for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 1 and
- 16 -
the conventional one shown in Fig. 30. In this measurement,
both saturable reactors were assembled in a KrF excimer laser
apparatus including the circuit shown in E'ig. 27.
Incidentally, the compression ratio is a value obtained by
dividing the pulse width of voltage V2 between the terminals of
the capacitor 207 generated after the turn-on of the thyratron
204 by the pulse width of voltage V0 between the terminals of
the capacitor 209. The results are shown in Table 1.
Table 1
~o~pression Ratio
At After After AfterAfter
Start 30 sec 60 sec 120 sec 300 sec
Saturable 5.5 5.3 5.2 5.1 5.1
Reactor of the
Present Invention*
20 Conventional
Saturable 5.5 5.2 4.6 4.3 3.9
Reactor**
Note: *: Shown in Fig. 1.
**: Shown in E`ig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. 1 and 30).
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
l~?~S~t
Effective cross section = 1.2 x 10 m for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m.
Repetition rate: 1 kHz.
In the present invention, extremely small variation
o~ the compression ratio with time is obtained, so that the
saturable reactor shows sufficient characteristics for
practical use On the other hand, in the conventional
saturable reactor shown in Fig. 30, the saturation magnetic
flux density of the magnetic cores decreases under the
influence of heat spots generated mainly inside the magnetic
cores, so that the compression ratio is drastically decreased.
With the same apparatuses and the same conditions as
in Table 1, the deterioration of properties after repeated
operations was evaluated. In this experiment, each saturable
reactor was operated for 5 minutes, cooled for a sufficient
period and then operated again, and this process was repeated.
At the time of each restart, the compression ratio was
measured. The results are shown in Table 2.
Table 2
Compression Ratio
25 Number of
Operation 1 10 20 30 100
Saturable 5.5 5-5 5-5 5-5 5-5
Reactor of the
30 Present Invention*
Conventional
Saturable 5.5 5.4 5.2 4.9 4.2
Reactor**
- 18 -
1~3~
'
Note: *: Shown in Fig. l.
**: Shown in Fig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. l and 30).
Magnetic ribbon~of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 m2 for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m.
Repetition rate: l kHz.
Operation time in each cycle: 5 minutes.
In the present invention, the compression ratio does
not depend on the number of operation, while in the
conventional saturable reactor, the magnetic properties of the
saturable reactor are deteriorated by heat spots generated
2~ during the operation.
Fig. 4 shows a saturable reactor for high-voltage
pulse generating apparatuses according to one embodiment of the
present invention. In Fig. 4, the same reference numerals are
used for the same parts as in Fig. l. Specifically, l denotes
an input or output terminal, 2 a coaxial cylindrical conductor,
3 an output or input terminal, 4 an inlet for a coolant, 5 an
outlet for a coolant, 6 a magnetic core assembly constituted by
a plurality of wound magnetic cores each composed of an
_ 19 --
` ~"~:a3~
amorphous magnetic ribbon and an insulating tape such as a
polyethylene terephthalate film tape, 11 a disc-shaped
insulating member for electrically isolating the input and
output terminals 1, 3 and for sealing a cavity defined by the
coaxial cylindrical conductor 2, 12 a gap between the radially
adjacent wound magnetic cores in each magnetic core assembly,
and 13 an insulating coolant guide member for keeping the
magnetic core assemblies separate from the coaxial cylindrical
conductor and from each other and for guiding the coolant such
that the end surfaces of the wound magnetic cores can be
uniformly cooled by the coolant. In this saturable reactor,
the coolant such as cooling oil is introduced into the cavity
through the inlet 4, and it flows in the cavity along the
course shown by the arrow. While uniformly cooling the end and
circumferential surfaces of each wound magnetic core, the
coolant is discharged through the outlet 5 and recycled by a
pump (not shown).
Fig. 5 shows the structure of the saturable magnetic
core assembly used in Fig. 4. In this embodiment, the
saturable magnetic core assembly is composed of 3 wound
magnetic cores 6a, 6b, 6c having different diameters and
disposed concentrically, and insulating spacers 14 provided
between the adjacent wound magnetic cores 6a and 6b, and 6b and
6c to provide annular spaces therebetween.
Fig. 6 shows the structure of each wound magnetic
core 6a, 6b, 6c shown in Fig. 5. In this embodiment, the wound
magnetic core 15 constituted by an amorphous magnetic ribbon
insulated by a polyethylene terephthalate film tape laminated
- 20 -
35~ :
between the adjacent layers of the amorphous magnetic ribbon is
supported by stainless steel rings 16 and 17 on its inner and
outer surfaces to prevent its deformation.
Figs. 7 A and 7 B show the structure of the
insulating coolant guide member for preventing the contact of
the wound magnetic cores with the coaxial cylindrical conductor
and from each other and for causing the cooling oil to flow
radially on the end surfaces of each magnetic core. In this
embodiment, 18 and 19 denote spacer portions for preventing the
wound magnetic cores 6 from being brought into con-tact with the
coaxial cylindrical conductor 2, and 20 denotes apertures for
determining the ~low direction of the cooling oil. A large
number of apertures 20 are provided in the insulating coolant
guide member 13 at such positions as to make sure that the end
sur~aces of the wound magnetic core are uniformly cooled.
Because of the above structure, the surface area of the
saturable magnetic core 6 can be made large, so that high
cooling efficiency of the magnetic cores can be expected.
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil, the variation of the compression ratio with time
was measured on the saturable reactor in this embodiment shown
in Fig. 4 and the conventional saturable reactor shown in Yig.
30, both of which were assembled in the KrF excimer laser
having the circuit shown in Fig. 27. The results are shown in
Table 3 together with experimental conditions.
- 21 -
;3~
Table 3
Comeression Ratio
At After After AfterAfter
Start 30 sec 60 sec 120 sec 300 sec
Saturable 5.5 5.4 5.3 5.3 5.3
10 Reactor of the
Present Invention*
Conventional
Saturable 5.5 5.2 4.6 4.3 3.9
15 Reactor**
Note: *: Shown in Fig. 4.
**: Shown in Fig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
;~ Saturable reactor (in Figs. 4 and 30)~
Magnetic ribbon of each magnetic core.
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m2 for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m
Repetition rate: 1 kHz
In the present invention, extremely small variation
of the compression ratio with time is obtained, so that the
saturable reactor shows sufficient characteristics for
- 22 -
3~9
practical use. On the other hand, in the conventional
saturable reactor, the saturation magnetic flux density of the
magnetic core decreases under the influence of the heat spots
generated mainly inside the magnetic cores, so that the
compression ratio is drastically decreased.
Further, the decrease in the compression ratio is
smaller in this embodiment (Fig. 4) than in the embodiment
shown in Fig. 1, which means that the saturable reactor of Fig.
4 can be subjected to a higher repetition rate.
With the same apparatuses and the same conditions as
in Table 3, the deterioration of properties after repeated
operations was evaluated. In this experiment, the saturable
reactor was operated for 5 minutes, cooled for a sufficient
period and then operated again, and this process was repeated.
At the time of each restart, the compression ratio was
measured. The results are shown in Table 4.
Table 4
Compression Ratio
20 Number
of Operation 1 10 20 _50 100
Saturable 5.5 5.5 5-5 5-5 5-5
Reactor of the
25 Present Invention*
Conventional
Saturable 5.5 5.4 5.2 4.9 4.2
Reactor**
Note: *: Shown in Fig. 4.
**: Shown in Fig. 30.
- 23
t,a,
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
Saturable reactor ~in Figs. 4 and 30).
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4~
Effective cross section = 1.2 x 10 3 m2 for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m.
Repetition rate: 1 k~z.
Operation time in each cycle: 5 minutes.
Fig. 8 shows a transformer, as a magnetic device for
high-voltage pulse generating apparatuses according to a
further embodiment of the present invention. In Fig. 8, 21
denotes one end of a primary winding, 22 a coaxial cylindrical
conductor constituting the prlmary winding having a turn number
of 1, 23 the other end of the primary winding, 24 an inlet for
a coolant, 25 an outlet for a coolant, 26 a plurality of wound
magnetic cores each constituted by a Co-base amorphous magnetic
ribbon, for instance, and an insulating tape such as a
polyethylene terephthalate film tape, 27 and 28 insulating ring
members for fixing the magnetic cores 26 and shutting the flow
of a coolant, 29 and 30 insulating coolant guide ring members
for keeping the adjacent magnetic cores separate from each
other and for permitting the coolant to pass therethrough such
that the end surfaces of the magnetic cores can be uniformly
cooled by the coolant, 31 one end of a secondary winding, 32 a
.
- 24 -
~3~3~1
72177-15
conductor consti-tuting the secondary winding having a turn number
of 6, 33 the other end of the secondary winding, and 3~ an insula-
ting seal member for insulating one end of the primary winding
from its other end and for sealing a cavity defined by the primary
winding. In this structure, the primary winding end 21 and the
~ secondary winding end 31 are connected. Further, this transformer
; includes insulating ring members 29, 30 having substantially the
- same structures as those shown in Figs. 2 and 3. In this trans-
former, a coolant such as a cooling oil is introduced into the
cavity of the coaxial cylindrical conductor (primary winding)
through the inlet 24, and it flows in the cavity along the course
of ~ ~ . While uniformly cooling the end surfaces of
each magnetic core 26, the coolant is discharged through the out-
let 25 and recycled by a pump (not shown).
With a silicone oil having a viscosity of 5 mm2/S as a
cooling oil, the variation of magnetic core loss with time was
measured on the transformer for high-voltage pulse generating
apparatuses in this embodiment shown in Fig. 8 and the convention-
al one shown in Fig. 31. Incidentally, the magnetic core loss is
expressed as 1.00 at start, and the magnetic core loss after a
certain number of operations is expressed by a ratio relative to
1.00. The results are shown in Table 5.
- 25 -
1~3S3~
Table 5
~aqnetic Core Loss
Number
of Operation 1 10 20 50 100 500
Transformer
of the Present 1.00 1.02 1.021.03 1.03 1.05
Invention~
Conventional
Transformer** 1.001.061.09 1.171.24 1.38
Note: *: Shown in Fig. 8.
**: Shown in Fig. 31.
Experimental Conditions:
Transformer tin Figs. 8 and 31).
Magnetic ribbon of each magnetic core:
20 Fe-base amorphous magnetic ribbon.
The number of magnetic cores: 3.
Effective cross section = 1.5 x 10 3 m for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m.
25 Operational magnetic flux density: 1.8 T.
Full width at half maxima: 1 ~s.
Repetition rate: 1 k~z.
Operation time in each cycle: 5 minutes.
In the present invention, sufficiently small
variation of the magnetic core loss with time is obtained, so
that the transformer shows sufficient characteristics for
practical use. On the other hand, in the conventional
transformer, the loss of the magnetic core drastically
- 26 -
increases under the influence of heat spots generated mainly
inside the magnetic cores.
FigO 9 shows a transformer, as a magnetic device for
high-voltage pulse generating apparatuses according to a still
further embodiment of the present invention. In Fig. 9, the
same reference numerals are assigned to the same parts as in
Fig. 8. Specifically, 21 denotes one end of a primary winding
having a turn number of 1, 22 a coaxial cylindrical conductor
constituting the primary winding, 23 the other end of the
primary winding, 24 an inlet for a coolant, 25 an outlet for a
coolant, 26 a plurality of wound magnetic core assemblies each
constituted by wound magnetic cores 35 composed of an Fe-base
amorphous magnetic ribbon, for instance, and an insulating tape
such as a polyethylene terephthalate film tape, 31 one end of a
secondary winding, 32 a conductor constituting the secondary
winding having a turn number of 6, 33 the other end of the
secondary winding, 34 an insulating seal member for insulating
one end of the primary winding from its other end and for
sealing a cavity defined by the primary windin~, and 36 an
~0 insulating coolant guide member for keeping the magnetic cores
separate from the coaxial cylindrical conductor 22 and from
each other and for permitting the coolant to pass therethrou~h
such that the end surfaces o~ the wound magnetic cores can be
uniformly cooled by the coolant. In this structure, the
primary winding end 21 and the secondary winding end 31 are
connected. Incidentally, in this transformer, the magnetic
core assembly 26 and a disc-shaped insulating coolant guide
member 36 have substantially the same structures as those shown
- 27 -
3~3
in Yigs. 5-7. In this transformer, a coolant such as a cooling
oil is introduced into the cavity of the coaxial cylindrical
conductor (primary winding) through the inlet 24, and it flows
in the cavity along the course shown by the arrow. While
uniformly cooling the end surfaces of each magnetic core 26,
the coolant is discharged through the outlet 25 and recycled by
a pump (not shown).
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil, the variation ofi~ magnetic core loss with time
, 10 was measured on the transformer for high-voltage pulse
. ::
generating apparatuses in this embodiment shown in Fig. 9 and
the conventional one shown in Fig. 31. Incidentally7 the
magnetic core loss is expressed as 1.00 at start, and the
magnetic core loss after a certain number of operations is
expressed by a ratio relative to 1.00. The results are shown
in Table 6.
Table 6
20 _ Maqnetlc Core Loss
Number of
Operation 1 10 20 50 100 500
Transformer
25 of the Present 1.00 1.00 1.011.02 1.02 1.02
Invention*
Conventional
Transformer**1.001.06 1.09 1.171.24 1.38
~ote: *: Shown in Fig. 9.
**: Shown in Fig. 31.
- 28 -
Experimental Conditions:
Transformer (in Figs. 9 and 31).
Magnetic ribbon of each magnetic core:
Fe-base amorphous magnetic ribbon.
The number of magnetic cores: 3.
Effective cross section = 1.5 x 10 3 m2 Eor
each magnetic core.
Mean magnetic path length: 380 x 10 3 m.
Operational magnetic flux density: 1.8 T.
Full width at half maxima: 1 ~s.
Repetition rate: l kHz.
Operation time in each cycle: 5 minutes.
In the present invention, sufficiently small
lS variation of the magnetic core loss with time is obtained, so
that the transformer shows sufficlent characteristics for
practical use. On the other hand, in the conventional
transformer, the loss of the magnetic cores drastically
increases under the influence of heat spots generated mainly
2~ inside the magnetic cores.
Further, the variation of the magnetic core loss with
time is smaller in this embodiment-shown in Fig. 9 than in the
embodiment shown in Fig. 8, which means that the transformer of
Fig. 9 can advantageously be subjected to a higher repetition
rate.
Fig. 10 shows an accelerator cell, as a magnetic
device for high-voltage pulse generating apparatuses according
to a still further embodiment of the present invention. In
- 29 -
3~
~ig. 10, 41a, 41b denote one terminal of an input winding, 42 a
coaxial cylindrical conductor constituting the input winding
having a turn number of 1, which has an cuter wall 42a, an
inner wall 42b and an end wall 42c for defining a cavity, 43a,
5 43b a ground terminal of the input winding, 44a, 44b an inlet
for a coolant, 45a, 45b an outlet for a coolant, 46 a plurality
of wound magnetic cores each constituted by an Fe-base
amorphous magnetic ribbon, for instance, and an insulating tape
such as a polyethylene terephthalate film tape, 47 and 48
insulating ring members for fixing the magnetic cores 46 and
- shutting the flow of a coolant, 51a, 51b a ground terminal of
an output winding, 52 a coaxial cylindrical conductor
constituting the output winding having a turn number of 1, 53
one terminal of the output winding, and 54 a conical insulating
lS seal member for sealing a space between the outer wall 42a of
the coaxial cylindrical conductor 42 and the coaxial
cylindrical conductor 52. In this structure, the ground
terminal 43a, 43b of the input winding 42 and the ground
terminal 51a, 51b of the output terminal 52 are connected. In
this accelerator cell, a coolant such as a cooling oil is
introduced into the cavity defined by the inner and outer walls
42a, 42b of the coaxial cylindrical conductor 42 through the
inlet 44a, 44b, and it flows in the cavity along the course of
~ . While uniformly cooling the end
surfaces of each magnetic core 46, the coolant is discharged
through the outlet 45a, 45b and recycled by a pump (not shown).
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil, the variation ofi~ magnetic core loss with time
_ 30 -
1~{~
was measured on the transformer for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 10 and
the conventional one shown in Fig. 32. Incidentally, the
magne-tic core loss is expressed as 1.00 at start, and the
magnetic core loss after a certain number of operations is
expressed by a ratio relative to 1.00. The results are shown
in Table 7.
Table 7
Magnetic Core Loss
Number
of Operation 1 10 20 50 100
Accelerator
15 Cell of the 1.00 1.04 1.07 1.09 1.12
Present Invention*
Conventional
Accelerator 1.00 1.11 1.22 1.37 1.54
Cell~*
Note: *: Shown in Fig. 10.
**: Shown in Fig. 32.
25 Experimental Conditions:
Accelerator cell (in Figs. 10 and 32).
Magnetic ribbon of each magnetic core:
Fe-base amorphous magnetic ribbon.
The number of magnetic cores: 3.
Effective cross section = 1.0 x 10-3 m2 for
each magnetic core.
Mean magnetic path length: 1.57 m.
Operational magnetic flux density: 1.8 T.
S3~
Full width at half maxima: 50 ns.
Repetition rate: 100 Hz.
Operation time in each cycle: 1 minute.
In the present invention, sufficiently small
variation of the magnetic core loss with time is obtained, so
that the accelerator cell shows sufficient characteristics for
practical use. On the other hand, in the conventional
accelerator cell, the loss of the magnetic cores drastically
increases under the influence of heat spots generated mainly
inside the magnetic cores.
Fig. 11 shows an accelerator cell, as a magnetic
device for high-voltage pulse generating apparatuses according
to a still further embodiment of the present invention. In
Fig. 11, the same reference numerals are assigned to the same
parts as in Fig. 10. Specifically, 41a, 41b denote one
; terminal of an input winding, 42 a coaxial cylindrical
conductor constituting the input winding having a turn number
of 1, which has an outer wall 42a, an inner wall 42b and an end
wall 42c for defining a cavity, 43a, 43b a ground terminal of
the input winding, 44a, 44b an inlet for a coolant, 45a~ 45b an
outlet for a coolant, 46 a plurality of magnetic core
assemblies each constituted by a plurality of wound magnetic
cores composed of an Fe-base amorphous magnetic ribbon, for
instance9 and an insulating tape such as a polyethylene
terephthalate film tape, 51a, 51b a ground terminal of an
output winding, 52 a coaxial cylindrical conductor constituting
the output winding having a turn number of 1, 53 one terminal
of the output winding, 54 a conical insulating seal member for
~3~3~
sealing a space between the outer wall 42a of the coaxial
cylindrical conductor 42 and the coaxial cylindrical conductor
52, 56 a plurality of disc-shaped insulating coolant guide
members each having a plurality of apertures positioned between
the radial gaps of the magnetic core assembly to uniformly cool
the end surfaces of the wound magnetic cores. In this
structure, the ground terminal 43a, 43b o~ the input windlng 42
and the ground terminal 51a, 51b of the output terminal 52 are
connected. In this accelerator cell, a coolant such as a
cooling oil is introduced into the cavity defined by the inner
and outer walls 42a, 42b of the coaxial cylindrical conductor
42 through the inlet 44a, 44b, and it flows in the cavity along
the course shown by the arrow. While uniformly cooling the end
surfaces of each magnetic core 46, the coolant is discharged
through the outlet 45a, 45b and recycled by a pump ~not shown).
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil, the variation of ~ magnetic core loss with time
was measured on the transformer for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 11 and
the conventional one shown in Fig. 32. Incidentally, the
magnetic core loss is expressed as 1.00 at start, and the
magnetic core loss after a certain number of operations is
expressed by a ratio relative to 1.00. The results are shown
in Table 8.
3~3
Table 8
Maqnetic Core Loss
Number
~ 1 10 20 50 100
Accelerator
Cell of the 1.00 1.03 1.04 1.04 1.05
Present Invention*
Conventional
Accelerator 1.00 1.11 1.22 1.37 1.54
Cell**
15 Note: ~: Shown in Fig. 11.
**: Shown in Fig. 32.
Experimental Conditions:
Accelerator cell ~in Figs. 11 and 32).
Magnetic ribbon of each magnetic core:
Fe-base amorphous magnetic ribbon.
The number of magnetic cores: 3.
Effective cross section = 1.0 x 10 m for
each magnetic core.
Mean magnetic path length: 1.57 m.
Operational magnetic flux density: 1.8 T.
Full width at half maxima: 50 ns.
Repetition rate: 100 Hz.
Operation time in each cycle: 1 minute.
30 In the present invention, sufficiently small
variation of the magnetic core loss with time is obtained, so
that the accelerator cell shows sufficient characteristics for
practical use. On the other hand, in the conventional
- 34 -
accelerator cell, the loss of the magnetic cores drastically
increases under the influence of heat spots generated mainly
inside the magnetic cores.
Fig. 12 shows a saturable reactor for high-voltage
pulse generating apparatuses according to a still further
embodiment of the present invention. In Fig. 12, the same
reference numerals are assigned to the same parts as in Fig. 1.
Specifically, 1 denotes an input or output terminal, 2 a
coaxial cylindrical conductor having an outer wall 2a, an inner
wall 2b and an end wall 2c for deflning a cavity, 3 an output
or input terminal, 4 an inlet for a coolant, 5 an outlet for a
coolant, 6 a plurality of wound magnetic cores each constituted
by a Co-base amorphous magnetic ribbon, for instance, and an
insulating tape such as a polyethylene terephthalate film tape,
11 an insulating member for electrically isolating the input
and output terminals 1, 3 and for sealing the cavity defined by
the coaxial cylindrical conductor 2, 107 and 108 insulating
ring members for fixing the magnetic cores 6 and shutting the
flow of a coolant, 109, 110, 111 and 112 insulating coolant
guide ring members for keeping the adjacent magnetic cores
separate from each other and for guiding the coolant to flow
such that the end surfaces of the magnetic cores can be
uniformly cooled. In this saturable reactor, the coolant such
as cooling oil is introduced into the cavity through the inlet
4, and it flows in the cavity along the course of ~
. While uniformly cooling the end surfaces of
each magnetic core 6, the coolant is discharged through the
outlet 5 and recycled by a pump (not shown).
- 35 -
r 3 5 3 ~
12177-15
Figure 13 is a cross-sectional view taken along the line
A~A in Figure 12, showing the relation between the inner
insulating coolant guide ring member 1~9 and the outer insulating
coolant guide ring member 110 in a space defined by the adjacent
magnetic cores 6. The inner insulating coolant guide ring member
109 and the outer insulating coolant guide ring member 110
respectively have only one notch or opening lO9a, llOa, and the
notches lO9a, llOa are located substantially at diametrically
opposite positions. In the positions of the notches lO9a, llOa
shown in Figure 13, the coolant flows from the notch lO9a to the
notch llOa substantially in a circumferential direction of the
magnetic core 6. Accordingly, the end suraces of each magnetic
core 6 are in contact with the coolant for a maximum period of
;~ time, meaning that the highes-t cooling eficiency can be achieved.
Incidentally, in Figure 13, the coolant flows circumferentially
from inside to outside.
Figure 21 shows the relations of the layer structure of
the wound magnetic core and the flow direction of the coolant. In
Figure 21, 81 denotes an insulating layer and 82 a magnetic ribbon
layer, and the symbol '~' means that the coolant flows upwardly
with respect to the plane of the paper. As is clear from Figure
21, the coolant can smoothly contact with the end surfaces of the
magnetic ribbon layers 82.
Figure 14 is a cross-sectional view taken along the line
B-B in Figure 12. Figure 14 shows the flow direction of the
coolant in a space labeled as ~ in Figure 12. Specifically, the
coolant flows circumferentially from outside to inside,
- 36 -
S3~3 :
just opposite to tbe case of Fig. 13. Like t'nis, the coolant
flows through all spaces between the magnetic cores 6 in
substantially the longest course of Q ~
~.
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil, the variat1on of a compression ratio with time
was measured on the saturable reactor for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 12 and
the conventional one shown in Fig. 30. In this measurement,
both saturable reactors were assembled in a KrF exci~er laser
apparatus including the circuit shown in FigO 27. The results
are shown in Table 9.
Table 9
Com~ression Ratio
At After After AfterAfter
Start 30 sec 60 sec 120 sec 3Q0 sec
20 Saturable 5.5 5.4 5.3 5.1 5.1
Reactor of the
Present Invention*
Conventional
25 Saturable 5.5 5.2 4.7 4.3 4.1
Reactor**
. .
Note: *: Shown in Fig. 12.
**: Shown in Fig. 30.
~xperimental Conditions:
Input: Vi = DC 30 kY.
Capacitance = 15 nF for capacitors 206, 207, 209.
_ 37 -
3~i3~
Saturable reactor (in Figs. 12 and 30)
Magnetic ribbon of each magnetic core:
Co~base amorphous magnetic ribbon.
The numker of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m~ for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m
Repetition rate: 3 kHz
In the present invention, extremely small variation
of the compression ratio with time is obtained, so that the
saturable reactor shows suficient characteristics for
practical use. On~the other hand, in the conventional
saturable reactor shown in Flg. 30, the operational magnetic
flux density aB of the magnetic cores decreases under the
influence of temperature increase caused by the magnetic core
loss, so that the compression ratio is drastically decreased.
; With the same apparatuses and the same conditions as
in Table 9, the deterioration of properties after repeated
:~,
operations was evaluated. In this experiment, each saturable
;reactor~ was operated for 5 minutès, cooled for a sufficlent
` ~ period and then operated agaln, and this process was repeated.
At the tlme of each restart, the compression ratio was
measured. The results are shown in Table 10.
- 38 -
.
?~
Table 10
_ Compression Ratio
5 Number of
Op_ration 1 10 20 30 100
Saturable 5.5 5.5 5.5 5.5 5.5
Reactor of the
10 Present Invention*
Conventional
Saturable 5.5 5.4 5.3 5.1 4.8
Reactor**
Note: *: Shown in Fig. 12.
**: Shown in Fig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. 12 and 30).
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m2 for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m.
Repetition rate: 3 kHz.
Operation time in each cycle: 5 minutes.
In the present invention, the compression ratio does
not depend on the number of operation, while in the
conventional saturable reactor, the magnetic properties of the
saturable reactor are deteriorated by heat spots generated
- 39 -
3~
inside the magnetic cores during the operation.
Fig. 15 shows a saturable reactor as a magnetic
device for high-voltage pulse generating apparatuses according
to a still further embodiment of the present invention. In
Fig. 15, the same reference numerals are assigned to the same
parts as in Fig. 12. Specifically, 1 denotes an input or
output terminal, 2 a coaxial cylindrical conductor having an
outer wall 2a, an inner wall 2b and an end wall 2c for defining
a cavity, 3 an output or input terminal, 4 an inlet for a
coolant, 5 an outlet for a coolant, 6 a plurality of wound
magnetic cores each constituted by a Co-base amorphous magnetic
ribbon, for instance, and an insulating tape such as a
polyethylene terephthalate film tape, 11 an insulating member
for electrically isolatlng the input and output terminals 1, 3
and for seaLing the cavity defined by the coaxial cylindrical
conductor 2, 127 and 128 insulating ring members for fixing the
magnetic cores 6 and shutting the flow of a coolant, 129 and
130 insulating coolant guide ring members for keeping the
adiacent magnetic cores separate from each other and for
guiding the coolant to flow such that the end surfaces of the
magnetic cores 6 can be uniformly cooled by the coolant. In
this saturable reactor, a coolant such as cooling oil is
introduced into the cavlty through the inlet 4, and it flows in
the cavity along the course of ~
While uniformly cooling the end surfaces of each magnetic core
6, the coolant lS discharged through the outlet 5 and recycled
by a pump (not shown).
Fig. 16 is a cross-sectional view taken along the
'
_ 40 -
line A-A in Fig. 15, showing the insulating coolant guide
member 129 which has an inner cylindrical portion and an outer
cylindrical portion integrally connected to each other by a
radial spacer. Since one notch of the inner cylindrical
portion and one notch of the outer cylindrical portion are
located near the same radial position, and since these notches
are separated by the radial spacer, the coolant flows
substantially along the entire circumference of the magnetic
core. In Fig. 16, the coolant flows circumferentially from
inside to outside. The insulating coolant guide member 130
shown in Fig. 17 has substantially the same structure as that
of the insulatin~ coolant guide member 129 except for the axial
direction of the notch. In the insulating coolant guide member
130, the coolant flows circumferentially from outside to
lS inside. Accordingly, the end surfaces of each magnetic core 6
are in contact with the coolant for a maximum period of time,
meaning that the highest cooling efficiency can be achieved.
Thus, the coolant flows through all spaces between the magnetic
cores 6 in substantially the longest course of
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil, the variation of ~ compression ratio with time
was measured on the saturable reactor for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 15 and
the conventional one shown in Fig. 30. In this measurement,
both saturable reactors were assembled in a KrF excimer laser
apparatus including the circuit shown in Fig. 27. The results
are shown in Table 11.
_ 41
Table 11
Compression Ratio
At After After AfterAfter
Start 30 sec 60 sec 120 sec 300 sec
Saturable 5.5 5.4 5.3 5.2 5.2
Reactor of the
Present Invention*
Conventional
Saturable 5.5 5.2 4.7 4.3 4.1
Reactor**
Note: *: Shown in Fig. 15.
**: Shown in Fig. 30.
Experimental Conditions:
20 Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. 15 and 30)
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m2 for
each magnetic core.
Mean magnetic path length: 380 x 10 3 m
Repetition rate: 3 kHz
In the present invention, extremely small variation
of the compression ratio with time is obtained, so that the
saturable reactor shows sufficient characteristics for
practical use.
- 42 -
With the same apparatuses and the same conditions as
in Table 11, the deterioration of properties after repeated
operations was evaluated. In this experiment, each saturable
reactor was operated for 5 minutes, cooled for a sufficient
period and then operated again, and this process was repeated.
At the time of each restart, the compression ratio was
measured. The results are shown in Table 12.
Table 12
Compression Ratio
Number of
Operatlon 1 10 20 50 100
15 Saturable 5.5 5.5 5.5 5.5 5.5
Reactor of the
Present Invention*
Conventional
20 Saturable 5.5 5.4 5.3 5.1 4.8
Reactor**
Note: *: Shown in Fig. 15.
- **: Shown in Fig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 15 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. 15 and 30).
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 m for
each magnetic core.
Mean magnetic path length: 380 x 10-3 m.
Repetition rate: 3 kH~.
Operation time in each cycle: 5 minutes.
In the present invention, the compression ratio does
~ ~ ~` 0~
~` 5 not depend on the number of ~, while in the
conventional saturable reactor, the magnetic properties of the
saturable reactor are deteriorated by heat spots generated
inside the magnetic cores during the operation.
Fig. 18 shows a saturable reactor as a magnetic
device for high-voltage pulse generating apparatuses according
to a still further embodiment of the present invention. In
Fig. 18, 141 denotes an input terminal, 142 an inner
cylindrical conductor with an oval or race track cross section,
143 an output terminal, 144a, 144b ground terminals, 145 an
outer cylindrical conductor with an oval cross section, 146a,
146b ground terminals, 147 an inlet for a coolant, 148 an
outlet for a coolant, 149 a plurality of wound magnetic cores
in the form of a race track each constituted by a Co-base
amorphous magnetic ribbon, for instance, and an insulating tape
such as a polyethylene terephthalate film tape, 150, 151
insulating ring members each having a path for permitting the
coolant to pass therethrough, 152, 153, 154, 155 insulating
coolant guide ring members for guiding the coolant to flow
circumferentially along the end surfaces of the magnetic cores,
156, 157 insulating seal members for electrically isolating the
two cylindrical conductors 142, 145 and for sealing the cavity
defined by the coaxially disposed cylindrical conductors 142,
145. In this saturable reactor, a coolant such as cooling oil
- 44 -
is introduced into the cavity through the inlet 147, and it
flows in the cavity along the course of Q
~ . While uniformly cooling the end surfaces of each magnetic
core 149, the coolant is discharged through the outLet 143 and
recycled by a pump ~not shown).
Fig. 19 is a cross-sectional view taken along the
line A-A in Fig. 18, showing an inner insulating coolant guide
ring member 152 which has a notch for permitting the coolant to
pass therethrough, and an outer insulating coolant guide ring
member 153 which has a notch for permitting the coolant to pass
therethrough. Since these notches are located diametrically
oppositely, the coolant flows substantially along the entire
circumference of the ~agnetic core. In Fig. 19, the coolant
flows circumferentially from inside to outside. In Fig. 20,
each of the inner and outer coolant guide ring members 1S4J 155
has a notch, and the two notches are located diametrically
oppositely as in Fig. 19. ~owever, their notches are directed
just oppositely to those of the coolant guide ring members 152,
I53. Therefore, in Fig. 20, the coolant flows
circumferentially from outside to inside. Accordingly, the end
surfaces of each magnetic core 149 are in contact with the
coolant for a maximum period of time, meaning that the highest
cooling efficiency can be achieved. Thus, the coolant flows
through alI spaces between the magnetic cores 149 in
substantially the longest course of ~
(~) -
With a silicone oil having a viscosity of 5 mm /S as
a cooling oil, the variation of ~compression ratio with time
- 45 -
was measured on the saturable reactor for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 18 and
the conventional one shown in Fig. 30. In this measurement,
both saturable reactors were assembled in a KrF excimer laser
apparatus including the circuit shown in Flg. 27. The results
are shown in Table 13.
Table 13
Compression Ratio
At After After AfterAfter
Start 30 sec 60 sec 120 sec 300 sec
Saturable 5.5 5.4 5.3 5.1 5.1
15 Reactor of the
Present Invention*
Conventional
Saturable 5.5 5.3 5.0 4.6 4.5
20 Reactor**
Note: *: Shown in Fig. 18.
**: Shown in Fig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 30 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. 18 and 30)
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m2 for
each magnetic core.
- 46 -
3~3~ -
Mean magnetic path length: 1.0 m
Repetition rate: 3 kHz
In the present invention, extremely small variation
of the compression ratio with time is obtained, so that the
saturable reactor shows sufficient characteristics for
practical use.
With the same apparatuses and the same conditions as
in Table 13, the deterioration of properties after repeated
operations was evaluated. In this experiment, each saturable
reactor was operated for 5 minutes7 cooled for a sufficient
period and then operated again7 and this process was repeated.
At the time of each~restart, the compression ratio was
measured. The results are shown in Table 14.
Table 14
Compression Ratio
Number of
Operation 1 10 20 30_ 100
Saturable 5.5 5.5 5.5 5-5 5-5
Reactor of the
Present Invention*
Conventional
Saturable 5.5 5.5 5-4 5-3 5.0
Reactor**
Note: *: Shown in Fig. 18.
30**: Shown in Fig. 30.
Experimental Conditions:
Input: Vi = DC 30 kV.
- 47 -
z~
Capacitance = 30 nF for capacitors 206, 207, 209.
Saturable reactor (in Figs. 18 and 30).
Magnetic ribbon of each magnetic core:
Co~base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m for
each magnetic core.
Mean magnetic path length: 1.0 m.
Repetition rate: 3 kHz.
Operation time in each cycle: 5 minutes.
In the present invention, the compression ratio does
v~ ~c ~s
`i not depend on the number of ~e~t~ , while in the
conventional saturable reactor, the magnetic properties of the
saturable reactor are deteriorated by heat spots generated
inside the magnetic cores during the operation.
Fig. 22 shows a saturable reactor as a magnetic
device for high-voltage pulse generating apparatuses according
to a still further embodiment of the present invention. This
saturable reactor comprises a cylindrical casing 171 and a pair
of insulating seal plates 180, 180 fixed to the cylindrical
casing 171 by bolts 170. Each insulating seal plate 180 is
provided with two terminals 161 or 169. Where the terminals
; 161 are input terminals, the terminals 169 are output terminals
and vice versa. The terminals 161 are connected to a
conductive disc plate 162 to which a terminal 163 is threaded.
Likewise, the terminals 169 are connected to a conductive disc
plate 168 to which a terminal 167 is threaded.
An insulating cylindrical core 173 is disposed in the
- 48 -
. . .
3~
center of the cylindrical casing 171, and both ends of the
insulating cylindrical core 173 are fixed to the conductive
disc plates 162, 168 by the terminals 161, 169 serv~ng as
threads. Provided around the insulating cylindrical core 173
is an insulating cylindrical member 174 extending along
substantially the entire length of the insulating cylindrical
core 173. The insulating cylindrical member 174 is fixed by a
pair of insulating rings 175 each positioned between the end of
the insulating cylindrical member 174 and the insulating disc
plates 162, 168.
A plurality of wound magnetic cores 172 are Eixed to
the insulating cylindrical member 174, and each of their outer
surfaces is fixed to the cylindrical casing 171 via an outer
insulating ring member 177 provided with an opening or a notch.
A notch of one outer insulating ring member 177 is positioned
diametrically opposite to a notch of the adjacent outer
insulating ring member. Further, an inner insulating ring
spacer 176 and an outer insulating ring spacer 183 are disposed
between the adjacent wound magnetic cores 172, and the outer
insulating ring spacer 183 is provided with a pair of openings
or notches diametrically opposite to each other. The outer
insulating ring spacers 183 are fixed by a pair of ring members
178 each positioned between the outer insulating ring spacer
and the insulating disc plate 180.
As shown in Fig. 24, both the insulating cylindrical
member 174 and the insulating ring member 177 have a plurality
of holes extending axially, and a wire 165 for winding
penetrates through each hole. It should be noted that a pair
- 49 -
~3S~
of wires 165, 165 are used for winding, and each wire 165 is
wound around the wound magnetic core 172 in a half circle
(180). As shown in Figs. 22 and 23, ends 164, 164 (only one
is shown) of the two wires 165, 165 are connected to the
terminal 163, and the other ends 166, 166 (only one is shown)
are connected to the terminal 167.
The cylindrical casing 171 is preferably made of a
conductive material so that it can serve as a ground terminal.
The cylindrical casing 171 is provided with an inlet 181 for a
coolant and an outlet 182 for a coolant.
In the saturable reactor thus constructed, the
coolant flows as shown by the arrows in Figs. 22-26.
Specifically, as shown in Figs. 22-26, the coolant is
introduced into a space between the insulating disc plate 180
and the wound magnetic core 172 and flows circumferentially
therein. It passes through the notch of the outer insulating
ring spacer 183 and the notch of the outer insulating ring
member 177 and introduced into the next space between the
adjacent wound magnetic cores 172. It also flows
circumferentially in the next space, and this process is
repeated. The coolant is finally discharged through the outlet
182.
In this saturable reactor, since wires penetrate
through a plurality of holes axially extending in the
insulating cylindrical member 174 and the outer insulating ring
members 177, a plurality of turns can be obtalned without
interfering~the flow of the coolant. In addition, since the
coolant flows circumferentially from one notch of the outer
-- 50 --
i3~
insulating ring spacer 183 to one notch of the same outer
insulating ring spacer 183 in each space, the end surfaces of
the wound magnetic cores are efficiently cooled.
With a silicone oil having a viscosity of 5 mm2/S as
a cooling oil~ the variation of ~compression ratio with time
was measured on the saturable reactor for high-voltage pulse
generating apparatuses in this embodiment shown in Fig. 22 and
the conventional one having the same structure as shown in Fig.
22 except that it does not have a coolant guide means composed
of outer insulating ring members 177 and outer insulating ring
spacers 183. In this measurement, both saturable reactors were
assembled in a TEA (transversely excited atmospheric
pressure)-CO2 laser apparatus including the circuit shown in
Fig. 27. The results are shown in Table 15.
Table 15
Compression Ratio
At After After AfterAfter
Start 30 sec 60 sec 120 sec 300 sec
Saturable
Reactor of the6.1 6.1 6.0 6.0 5.9
Present Invention*
Conventional
Saturable 6.1 5.9 5.7 5.5 5.3
Reactor**
Note: ~: Shown in Fig. 22.
**: Shown in Fig. 22 except for the coolant
guide means.
_ 51 -
:~2~3~;3~
Experimental Conditions:
Input: Vi = DC 30 kV.
Capacitance = 30 nF for capacitors 206, 207, 209.
Both saturable reactors
Magnetic ribbon of each magnetic core-
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m for
each magnetic core.
Mean magnetic path length: 380 x 10 m
Repetition rate: 3 kHz
In the present invention, extremely small variation
of the compression ratio with time is obtained, so that the
saturable reactor shows sufficient characteristics for
practical use.
With the same apparatuses and the same conditions as
in Table 159 the deterioration of properties after repeated
operations was evaluated. In this experiment, each saturable
reactor was operated for 5 minutes, cooled for a sufficient
period and then operated again, and this process was repeated.
At the time of each restart, the compression ratio was
~ measured. The results are shown in Table 16.
,~ :
- 52 -
3S3~
Table 16
Compression Ratio
5 Number of
Operation l 10 20 30 _ 100
Saturable
Reactor of the 6.1 6.1 6.1 6.1 6.Q
10 Present Invention*
Conventional
Saturable 6.1 6.1 6.0 5.8 5.7
Reactor**
Note: *: Shown in Fig. 22.
**: Shown in Fig. 22 except for the coolant
guide means.
Capacitance = 30 nF for capacitors 206, 207, 209.
Both saturable reactors.
Magnetic ribbon of each magnetic core:
Co-base amorphous magnetic ribbon.
The number of magnetic cores: 4.
Effective cross section = 1.2 x 10 3 m2 for
each magnetic core.
Mean magnetic path length: 380 x10 3 m.
Repetition rate: 3 kHz.
Operation time in each cycle: 5 minutes.
In the present invention, the compression ratio does
~ ~o~s
not depend on the number of epcra-t~ , while in the
;~ conventional saturable reactor, the magnetic properties of the
saturable reactor are deteriorated by heat spots generated
inside the magnetic cores during the operation.
As described above in detail, since the wound
- 53 -
magnetic COr2S are effectively cooled in the present invention,
the temperature increase of the magnetic core, particularly
heat spots can be prevented.
Particularly when the wound magnetic cores are
constituted by amorphous magnetic ribbons laminated with
insulating layers, the deterioration of their magnetic
properties is irreversible. Accordingly, it is extremely
important to prevent the generation of the heat spots inside
the magnetic cores. Further, although the magnetic ribbon
laminated with the insulating layer can hardly be cooled from
its circumferential surface, the wound magnetic core can be
easily cooled from its axial ends because the side ends of the
magnetic ribbon are exposed at the axial ends of the wound
magnetic core~ Therefore, the manner of flowing the coolant in
the magnetic device according to the present invention is
extremely effective to achieve a high cooling efficiency.
Because of the above structural features, the
magnetic device of the present invention is less susceptible to
deterioration in magnetic properties even after high repetition
rate operations. Therefore, it can be repeatedly used for a
long period of time.
The magnetic devices of the present invention can be
utilized not only as saturable reactors but also as
transformers, accelerator cells in linear induction
accelerators, choke coils, etc. for achieving the same effects.
- 54 -
