Valery B. Zorin

High-power ultrawideband electromagnetic pulse radiation

Basing on energetic processes studying in the near-field radiator zone, a new concept of antenna synthesizing for ultrawideband electromagnetic pulse radiation has been suggested. The results of experimental investigations of the antennae developed with using of this concept for high-power applications are presented. The antennae have small dimensions, high electrical strength, cardioid pattern with linear polarization of the pulse radiated and they are ideally adapted to be used as a steering antenna array element. A high-voltage nanosecond bipolar pulse generator design to excite antennae is described.

A Compact High Current Generator for X-Ray Radiography

X-generator was designed for small scale experiments with imploding liners, especially X-pinches. The generator consists of the capacitor bank, multi-channel multi-gap spark switch, flat current buses, load chamber and built-in high voltage triggering generator. The capacitor bank consists of 12 General Atomics 35404 type capacitors (20 nF, 25 nH, 0.2 Ohm, 100 kV). It stores ~0.8 kJ at 80 kV charging voltage. . Each three capacitors are commuted to a load by multi-gap spark switch, which is able to commute by 8 parallel channels. Switches operate in ambient air at atmospheric pressure. The X-generator was tested with 5 and 10.5 nH inductive loads. At 76 kV charging voltage the generator provides ~260 kA with 120 ns risetime with 5 nH inductive load and -220 kA with 145 ns risetime with 10.5 nH. Delay of output pulse relatively to high voltage triggering pulse was 65 ns with 5 ns jitter ( at 76 kV charging voltage). Dimensions of the generator are 1240times1240times225 mm and weight is ~250 kg, so it could be easily employed for variety of applications.

Megaampere Submicrosecond Generator GIT-32

The GIT-32 is current generator developed by IHCE for Weizmann Institute of Science (Israel), devoted for experiments with current carrying pulsed plasma. Main parts of the generator are capacitor bank and multichannel multi-gap spark switch. Generator consists of four identical sections, connected in parallel to one load. Capacitor bank is assembled from 32 IEK-100-0.17 (0.17 muF, 40 nH, 100 kV) capacitors, connected in parallel. It stores ~ 20 kl at 85 kV charging voltage. Each two capacitors are commuted to a load by multi-gap spark switch, which is able to commute by 8 parallel channels. Inductance of the generator is ~ 10 nH, internal resistance ~ 0.005 Ohm. The GIT-32 generator was tested with 10, 15 and 20 nH inductive loads. At 10 nH load and 80 kV of charging voltage it provides 1 MA of current amplitude with 500 ns risetime with damping resistors in discharge circuit and 1.34 MA/570 ns without resistors. The generator operates reliably without any adjustments in 40divide80 kV range of charging voltage. The maximum jitter at 40 kV charging voltage is about 7 ns. The generator is quite compact: dimensions are 3300 x 3300 x 400 mm3 and total weight is about 2500 kg.

High-energy wide-aperture lasers pumped by radially convergent electron beams

The results of the experimental study of UV and IR lasers pumped by electron beams are presented. The accelerators with radially convergent electron beam for pumping gas mixtures under pressure up to 3 atm were used. Laser radiation energies of up to 2 kJ, 200 J, 100 J, 50 J have been obtained at the wavelengths of 308 nm, ~2.8 μm, 250 nm and 1.73 μm, 2.03 μm, correspondingly.

Experimental study on a long-pulse excimer laser system

A four-stage XeCl laser system named Photons has been developed for studying laser interaction with materials. The Photons are outlined and preliminary results characterizing the system are given. The master oscillator Photon-1 can provide “seed” light with laser energy of about 40mJ, pulse duration of about 250ns and good beam quality of nearly diffraction-limited divergence angle and narrow line width less than 1 cm-1 for whole system. The output energy of laser system of 251J has been obtained by four-stage amplification. The synchronization among five lasers is realized by the combination of low voltage timer, high voltage synchronic generators and compensated cables. The demonstration shows Photons good operation with low jitter of less than ±20ns.

E-beam accelerator for eximer laser

A high current e-beam accelerator for pumping of the 200 liter eximer laser is developed providing electron energy of 550 keV, diode current of 320 kA, e-beam current of 250 kA. The high voltage part of the accelerator consists of two linear transformers with the stored energy of 98 kJ. In order to reduce the influence of the self magnetic field on e-beam formation the vacuum diode is divided into 6 separate magnetically isolated diodes.