Compact Nanosecond Pulse Generator

Pulsed Power Technology
Required parameters were chosen by the EEC algorithm
[7]. With these parameters, the EEC’s slightly
limit the current during its rise time (Fig. 6, а), but
ensure a current cutoff at the instant the energy in the
capacitor is close to zero (Fig. 6, b). An example of
calculated waveforms of the current and voltage is
shown in Fig. 6. The calculation was performed for
30 Cu wires of length 10 cm and diameter 70 µm.
I C , kA
370 J/l at an electric field strength of 200 kV/mm. The
volume of the active part was 2.3 l. The capacitorswitch
assembly in the short-circuit mode produced a
current up to 200 kA in 100 ns at a charge voltage of
90 kV. The dimensions of the capacitor active part are
Ø80 × Ø160 × 160 mm. The rate of rise of the current
at an X-pinch load (four Ø15-m tungsten wires) is
140 kA/70 ns and the X-ray pulsewidth is 2 ns. The
peculiarity of this load is that it absorbs a small
amount of energy compared to the energy stored in the
capacitor. Therefore it was proposed to use exploded
wires in the discharge circuit of the capacitor to ensure
a current cutoff at the instant the energy in the capacitor
is close to zero. Thus, it will be possible to suppress
or preclude the oscillation mode of the capacitor
and hence to increase its lifetime.
References
U, kV
T, ns
а
T, ns
b
Fig. 6. Calculated waveforms of the load current (а) and
voltage across different circuit elements (b)
Conclusion
The compact nanosecond pulse generator was designed
and tested. The generator has a specially designed
assembly consisting of an HCEIcap 100-0.2
capacitor and a multigap switch. The total inductance
of the assembly is 20 nH. The modifications made in
the design allowed an increase in energy density up to
[1] A.A. Kim, B.M. Kovalchuk, A.N. Bastrikov et al.,
in Proc. of the 13th IEEE Int. Pulsed Power Conf.,
2001, V. 2, pp. 1491–1494.
[2] N.A. Ratakhin, V.F. Feduschak, A.A. Erfort,
A.V. Saushkin, N.V. Zharova, S.A. Chaikovsky,
and V.I. Oreshkin, “Table-top Pulse Power Generator
for Soft X-Ray Radiography”, in Proc. of
the 14th Int. Symp. on High Current Electronics,
Tomsk, 2006, pp. 511–513.
[3] V.F. Feduschak, N.V. Zharova, I.V. Lavrinovich et
al., “Compact Pulsed Power Generator”, in Proc.
of the 15th Int. Symp. on High Current Electronics,
Tomsk, 2008, pp. 303–304.
[4] N.A. Ratakhin, V.F. Fedushchak, A.A. Erfort et
al., “Development of high-current pulse capacitors
rated at 100 kV”, in Proc. of Int. Conf. on Physics
of Pulsed Discharges in Condensed Media, Nikolaev,
2009, pp. 140–142.
[5] A.A. Zherlitsyn, B.M. Kovalchuk, A.V. Kharlov,
and E.V. Kumpyak, “Pulsed Current Generator
with Variable Pulse Shape”, in Proc. of the 14th
Int. Symp. on High Current Electronics, Tomsk,
2006, pp. 287–289.
[6] High-voltage capacitor with a built-in controllable
switch by V.S. Verkhovsky, N.V. Zharova,
I.V. Lavrinovich, and V.F. Feduschak, RF Patent
75783: IPC H 01 G 4/00, H 01 T 2/02, applied
08.04.08, published 20.08.08, Bulletin No. 23
[7] E.I. Azarkevich, A.V. Kobluchko, Yu.A. Kotov,
and T.A. Lisetskaya, “Computational model of an
electrical-explosion opening switch, High-voltage
spark gap and electrical-explosion opening
switches”, in Proc. of a Joint Meeting of Scientific
Councils of the USSR AS on Scientific Foundations
of Electrophysics and Electrical Power Engineering
and Problems of Pulsed Power Technology,
Tomsk, Nov 27–28, 1986, pp. 109–111.
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