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Title: Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium–tritium fillings

Abstract

The process of hard X-ray (HXR) generation in plasma focus (PF) chambers was studied experimentally. The radiation was recorded using scintillation detectors with a high time resolution and thermoluminescent detectors in combination with the method of absorbing filters. Time-resolved analysis of the processes of neutron and X-ray generation in PFs is performed. The spectra of HXR emission from PF chambers with deuterium and deuterium–tritium fillings are determined. In experiments with PF chambers filled with a deuterium–tritium mixture, in addition to the HXR pulse with photon energies of up to 200–300 keV, a γ-ray pulse with photon energies of up to 2.5–3.0 MeV is recorded, and a mechanism of its generation is proposed.

Authors:
; ; ; ; ; ;  [1]
  1. All-Russia Research Institute of Automatics (Russian Federation)
Publication Date:
OSTI Identifier:
22471837
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Physics Reports; Journal Volume: 42; Journal Issue: 1; Other Information: Copyright (c) 2016 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DEUTERIUM; D-T OPERATION; HARD X RADIATION; KEV RANGE; MEV RANGE; NEUTRONS; PHOTONS; PLASMA FOCUS; SCINTILLATION COUNTERS; TIME RESOLUTION; TRITIUM

Citation Formats

Dulatov, A. K., E-mail: bogolubov@vniia.ru, Krapiva, P. S., Lemeshko, B. D., Mikhailov, Yu. V., Moskalenko, I. N., Prokuratov, I. A., and Selifanov, A. N. Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium–tritium fillings. United States: N. p., 2016. Web. doi:10.1134/S1063780X16010050.
Dulatov, A. K., E-mail: bogolubov@vniia.ru, Krapiva, P. S., Lemeshko, B. D., Mikhailov, Yu. V., Moskalenko, I. N., Prokuratov, I. A., & Selifanov, A. N. Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium–tritium fillings. United States. doi:10.1134/S1063780X16010050.
Dulatov, A. K., E-mail: bogolubov@vniia.ru, Krapiva, P. S., Lemeshko, B. D., Mikhailov, Yu. V., Moskalenko, I. N., Prokuratov, I. A., and Selifanov, A. N. Fri . "Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium–tritium fillings". United States. doi:10.1134/S1063780X16010050.
@article{osti_22471837,
title = {Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium–tritium fillings},
author = {Dulatov, A. K., E-mail: bogolubov@vniia.ru and Krapiva, P. S. and Lemeshko, B. D. and Mikhailov, Yu. V. and Moskalenko, I. N. and Prokuratov, I. A. and Selifanov, A. N.},
abstractNote = {The process of hard X-ray (HXR) generation in plasma focus (PF) chambers was studied experimentally. The radiation was recorded using scintillation detectors with a high time resolution and thermoluminescent detectors in combination with the method of absorbing filters. Time-resolved analysis of the processes of neutron and X-ray generation in PFs is performed. The spectra of HXR emission from PF chambers with deuterium and deuterium–tritium fillings are determined. In experiments with PF chambers filled with a deuterium–tritium mixture, in addition to the HXR pulse with photon energies of up to 200–300 keV, a γ-ray pulse with photon energies of up to 2.5–3.0 MeV is recorded, and a mechanism of its generation is proposed.},
doi = {10.1134/S1063780X16010050},
journal = {Plasma Physics Reports},
number = 1,
volume = 42,
place = {United States},
year = {Fri Jan 15 00:00:00 EST 2016},
month = {Fri Jan 15 00:00:00 EST 2016}
}
  • In a 200 J fast miniature plasma focus device about 17- and 10-fold increase in x-ray yield in spectral ranges of 0.9-1.6 keV and 3.2-7.7 keV, respectively, have been obtained with deuterium-krypton (D{sub 2}-Kr) admixture at operating pressures of {<=}0.4 mbar. In the pressure range of >0.4-1.4 mbar, about twofold magnification in average x-ray yield along with broadening of optimum pressure range in both spectral ranges were obtained for D{sub 2}-Kr admixtures. An order of magnitude enhancement in x-ray yields at low pressures for admixture operation will help in achieving high performance device efficiency for lithography and micromachining applications.
  • Multi ion beam and hard x-ray emissions were detected in a high inductance (more than 100 nH) Mather type plasma focus (PF) device at different filling gas pressures and charging voltages. The signal analysis was performed through the current trace, as it is the fundamental signal from which all of the phenomena in a PF device can be extracted. Two different fitting processes were carried out according to Lee's computational (snow-plow) model. In the first process, only plasma dynamics and classical (Spitzer) resistances were considered as energy consumer parameters for plasma. This led to an unsuccessful fitting and did notmore » answer the energy transfer mechanism into plasma. A second fitting process was considered through the addition of anomalous resistance, which provided the best fit. Anomalous resistance was the source of long decrease in current trace, and multi dips and multi peaks of high voltage probe. Multi-peak features were interpreted considering the second fitting process along with the mechanisms for ion beam production and hard x-ray emission. To show the important role of the anomalous resistance, the duration of the current drop was discussed.« less
  • It is shown that the accuracy of time-integrated measurements of pulsed X-ray emission from hot plasma with calibrated thermocouple calorimeters is mainly determined by two factors. The first and the most important factor is heating of the filter by the absorbed X-rays; as a result, the calorimeter measures the thermal radiation of the filter, which causes appreciable distortion of the temporal profile and amplitude of the recorded signal. The second factor is the dependence of the effective depth of X-ray absorption in the dielectric that covers the entrance window of the calorimeter on the energy of X-ray photons, i.e., onmore » the recorded radiation spectrum. The results of model calculations of the calorimeter signal are compared with the experimental data.« less
  • The region of neutron generation in a bubble chamber with a plasma focus was measured by means of a raster technique and a pinhole camera. A high-efficiency bubble chamber with high spatial resolution was used to obtain the neutron-diffraction patterns in the basic measurements. The diameter of the neutron source was 2 mm and its length along the chamber axis was 5--12 mm.
  • Features of energetic charged particle beams and x-ray emission in a low energy (1–2 kJ) plasma focus (DPF) device are described and the possible mechanism are explained based on circuit analyses and energy balance in the DPF system. In particular, the resistance and the voltage across the plasma column are estimated to explain the mechanisms of the generation of particle beams and hard x-ray. The analysis shows that the total inductance of a DPF might have played a role for enhancement of the particle beams and x-ray emissions during the phase of anomalous resistance.