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Title: Catalytic action of {beta} source on x-ray emission from plasma focus

Abstract

The influence of preionization around the insulator sleeve by a mesh-type {beta} source ({sub 28}Ni{sup 63}) for the x-ray emission from a (2.3-3.9 kJ) plasma focus device is investigated. Quantrad Si p-i-n diodes along with suitable filters are employed as time-resolved x-ray detectors and a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray emission in 4{pi} geometry is measured as a function of argon and hydrogen gas filling pressures with and without {beta} source at different charging voltages. It is found that the pressure range for the x-ray emission is broadened, x-ray emission is enhanced, and shot to shot reproducibility is improved with the {beta} source. With argon, the Cu K{alpha} emission is estimated to be 27.14 J with an efficiency of 0.7% for {beta} source and 21.5 J with an efficiency of 0.55% without {beta} source. The maximum x-ray yield in 4{pi} geometry is found to be about 68.90 J with an efficiency of 1.8% for {beta} source and 54.58 J with an efficiency of 1.4% without {beta} source. With hydrogen, Cu K{alpha} emission is 11.82 J with an efficiency of 0.32% for {beta} source and 10.07 J with an efficiency of 0.27% without {beta} source.more » The maximum x-ray yield in 4{pi} geometry is found to be 30.20 J with an efficiency of 0.77% for {beta} source and 25.58 J with an efficiency of 0.6% without {beta} source. The x-ray emission with Pb insert at the anode tip without {beta} source is also investigated and found to be reproducible and significantly high. The maximum x-ray yield is estimated to be 46.6 J in 4{pi} geometry with an efficiency of 1.4% at 23 kV charging voltage. However, degradation of x-ray yield is observed when charging voltage exceeds 23 kV for Pb insert. From pinhole images it is observed that the x-ray emission due to the bombardment of electrons at the anode tip is dominant in both with and without {beta} source.« less

Authors:
; ; ; ; ;  [1];  [2];  [2];  [2]
  1. Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan)
  2. (Pakistan)
Publication Date:
OSTI Identifier:
20778558
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 77; Journal Issue: 1; Other Information: DOI: 10.1063/1.2162451; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANODES; ARGON; CAMERAS; EFFICIENCY; ELECTRIC POTENTIAL; EMISSION; GEOMETRY; HYDROGEN; PLASMA; PLASMA FOCUS; PLASMA FOCUS DEVICES; TIME RESOLUTION; X RADIATION; X-RAY SOURCES; YIELDS

Citation Formats

Ahmad, S., Sadiq, Mehboob, Hussain, S., Shafiq, M., Zakaullah, M., Waheed, A., Department of Physics, University of Sargodha, Sargodha, Department of Physics, Quaid-i-Azam University, 45320 Islamabad, and PINSTECH, P.O. Box 1331, 44000 Islamabad. Catalytic action of {beta} source on x-ray emission from plasma focus. United States: N. p., 2006. Web. doi:10.1063/1.2162451.
Ahmad, S., Sadiq, Mehboob, Hussain, S., Shafiq, M., Zakaullah, M., Waheed, A., Department of Physics, University of Sargodha, Sargodha, Department of Physics, Quaid-i-Azam University, 45320 Islamabad, & PINSTECH, P.O. Box 1331, 44000 Islamabad. Catalytic action of {beta} source on x-ray emission from plasma focus. United States. doi:10.1063/1.2162451.
Ahmad, S., Sadiq, Mehboob, Hussain, S., Shafiq, M., Zakaullah, M., Waheed, A., Department of Physics, University of Sargodha, Sargodha, Department of Physics, Quaid-i-Azam University, 45320 Islamabad, and PINSTECH, P.O. Box 1331, 44000 Islamabad. Sun . "Catalytic action of {beta} source on x-ray emission from plasma focus". United States. doi:10.1063/1.2162451.
@article{osti_20778558,
title = {Catalytic action of {beta} source on x-ray emission from plasma focus},
author = {Ahmad, S. and Sadiq, Mehboob and Hussain, S. and Shafiq, M. and Zakaullah, M. and Waheed, A. and Department of Physics, University of Sargodha, Sargodha and Department of Physics, Quaid-i-Azam University, 45320 Islamabad and PINSTECH, P.O. Box 1331, 44000 Islamabad},
abstractNote = {The influence of preionization around the insulator sleeve by a mesh-type {beta} source ({sub 28}Ni{sup 63}) for the x-ray emission from a (2.3-3.9 kJ) plasma focus device is investigated. Quantrad Si p-i-n diodes along with suitable filters are employed as time-resolved x-ray detectors and a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray emission in 4{pi} geometry is measured as a function of argon and hydrogen gas filling pressures with and without {beta} source at different charging voltages. It is found that the pressure range for the x-ray emission is broadened, x-ray emission is enhanced, and shot to shot reproducibility is improved with the {beta} source. With argon, the Cu K{alpha} emission is estimated to be 27.14 J with an efficiency of 0.7% for {beta} source and 21.5 J with an efficiency of 0.55% without {beta} source. The maximum x-ray yield in 4{pi} geometry is found to be about 68.90 J with an efficiency of 1.8% for {beta} source and 54.58 J with an efficiency of 1.4% without {beta} source. With hydrogen, Cu K{alpha} emission is 11.82 J with an efficiency of 0.32% for {beta} source and 10.07 J with an efficiency of 0.27% without {beta} source. The maximum x-ray yield in 4{pi} geometry is found to be 30.20 J with an efficiency of 0.77% for {beta} source and 25.58 J with an efficiency of 0.6% without {beta} source. The x-ray emission with Pb insert at the anode tip without {beta} source is also investigated and found to be reproducible and significantly high. The maximum x-ray yield is estimated to be 46.6 J in 4{pi} geometry with an efficiency of 1.4% at 23 kV charging voltage. However, degradation of x-ray yield is observed when charging voltage exceeds 23 kV for Pb insert. From pinhole images it is observed that the x-ray emission due to the bombardment of electrons at the anode tip is dominant in both with and without {beta} source.},
doi = {10.1063/1.2162451},
journal = {Review of Scientific Instruments},
number = 1,
volume = 77,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}
  • Experiments on the plasma focus of a coaxial accelerator with pulsed injection of the working gas are reported. The primary method used to study the plasma density was laser interferometry with large observation field and a high time resolution. The total neutron yield was also measured by an induced-activity method, and the soft x radiation was measured with a pinhole camera. The experiments were carried out under various accelerator operating conditions and with various gases. At high gradients of the neutral gas density and at high discharge currents (approx.400 kA) turbulence occurs in the plasma focus. Under certain conditions themore » instabilities do not disrupt the flow either in the coaxial system or in the plasma focusing region. Instabilities of the plasma focus are responsible for the production of fast electrons, heating of the plasma, and for the emission of x rays and neutrons. A study of the temporal characteristics of the observed phenomena shows that all occur simultaneously but may repeat several times in the course of the discharge.« less
  • The effect of preionization induced by depleted uranium ({sub 92}U{sup 238}) around the insulator sleeve on the x-ray emission of (2.3-3.9 kJ) plasma focus device is investigated by employing Quantrad Si p-i-n diodes and a multipinhole camera. X-ray emission in 4{pi} geometry is measured as a function of charging voltage with and without preionization. It is found that the preionization enhances Cu K{alpha} and total x-ray yield about 100%, broadens the x-ray emission pressure range and x-ray pulse width, and improves shot to shot reproducibility of plasma focus operation. The pinhole images of x-ray emitting zones indicate that dominant x-raymore » emission is from the anode tip.« less
  • X-ray emission from a 2.3-5.3 kJ Mather-type plasma focus [Phys. Fluids 7, 5 (1964)] employing copper, molybdenum, and tungsten anode tip is studied. Argon is used as a working gas. Characteristic Cu K{alpha} and Mo K-series emission and their ratio to the continuous x-rays are determined. From the variation of the x-ray yield data with filling pressure at different charging voltages, scaling laws are obtained. X-ray pinhole images demonstrate that a significant amount of x-ray emission is from the anode tip. The comparison of the ratio of characteristic to continuum radiation for copper anode with typical x-ray tube data revealsmore » that the contribution of very high energy electron beam from the focus region for x-ray generation through thick target bremsstrahlung mechanism is not significant. Rather, electrons with energy of the order of, or even less than, the charging voltage are responsible for bulk of the x-ray emission.« less
  • An indirect method to infer the spectra, based on the measurement of the beam intensity transmission through different metallic samples, is described in this communication. A Plasma Focus device (5.67 kJ, 30 kV) was studied as a pulsed hard x ray source, operated with deuterium at a filling pressure in the range of 3 to 5 mbar. Relevant spectral components belonging to the 50 - 150 keV range with a single maximum located in the 75 - 85 keV region were obtained for the radiation coming out of the Plasma Focus chamber, which is made of stainless steel.