V. A. Gribkov

A Powerful Soft X-ray Source for X-ray Lithography Based on Plasma Focusing

A source of soft X-ray emission (9?14?) based on the miniature 15kJ plasma focus was developed and tested. The X-ray emission was channelled along the chamber axis through an opening in the inner electrode (anode). A regime with a mean output of more than 100 J per discharge was found. At a discharge current of 280kA and repetition rate of 3.5Hz achieved by the device, its lifetime was estimated to be 107 commutations (about a year of continuous operation). A demonstration experiment on irradiation of an X-ray resist is discussed.

On the Possible Mechanisms of Activation Changes of Enzymes under Pulsed Irradiation

Classical radiation biology, radiation treatment of patients, and pulsed radiation chemistry usually deal with weak beams of radiation and operate in terms of dose (D). In this case, only the absolute number of ionizing particles or photons interacting with the object independently of one another is important. In this work, we resume our previous investigations of enzyme activation/inactivation produced by pulsed ionizing radiation from a dense plasma focus (DPF) device at a very short and intense irradiation process, when the concentrations of spurs and blobs are sufficiently dense to allow the micro-volumes to overlap each other. The time interval is small compared with the corresponding biochemical process. It is shown that the irradiation of biological objects for a few nanoseconds by beams of x-ray photons with a low dose (D ∼ 10-6–10-3 Gy) but at a high dose power (D/τ∼103–105 Gy/s) may be of a collective nature and result in synergetic effects. In particular, it was found that a remarkable activation/inactivation of enzymes (horseradish peroxidase, angiotensin-converting-enzyme) takes place at low doses in these regimes. The results of irradiating the above-mentioned enzymes in vitro with x-rays of nanosecond pulse duration coming from a dense plasma focus are presented here. Neutrons (2.5 MeV, 103–105 n/cm2 and x-ray photons of different energy ranges (7–9 keV and 20–200 keV) together with dose power factors are analyzed as possible reasons for the activation/inactivation of enzymes in various dose ranges. Our results are compared to those of the same experiments conducted with continuous x-ray sources based on a classical x-ray tube and on a 137Cs-isotope source (D∼10-3–102 Gy).

High-power 20-channel neodymium glass laser and combined laser and beam heating of a plasma

A high-power 20-channel neodymium-glass laser is described (energy i kJ, pulse duration 2 nsec). It is part of the “Flora” facility intended for combined simultaneous heating of a plasma by powerful laser radiation (PLR) and by a relativistic electron beam (REB) produced in a facility of the “plasma focus” type. The paper deals theoretically with the processes of combined interaction of PLR and REB with a current plasma and a solid target.