Study of molybdenum K-series line radiation emission from a low energy plasma focus (original) (raw)
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Physics Letters A, 2006
X-rays emission from a low energy (1.4-5.3 kJ) Mather-type plasma focus device with different (Cu, Mo, W and Pb) inserts at the anode tip is reported. The space and time resolved X-ray emission characteristics are investigated by using a multichannel pindiode spectrometer and a simple pinhole camera with appropriate filters. The variation of total X-ray yield and corresponding efficiency with discharge current, charging voltage and stored energy is investigated. At optimum conditions, the maximum X-ray yield in 4π-geometry is found to be 67.6, 62.4, 64 and 46.5 J/shot with Cu tip, Mo, W and Pb inserted anodes, respectively, and corresponding efficiencies for X-ray generation are 1.5, 1.4, 1.2 and 1.4%. In case of Pb inserted anode X-ray yield deterioration is observed for charging voltages grater than 23 kV. Pinhole images of the X-ray emitting sites reveal that soft X-rays are emitted from focus region, whereas hard X-rays are emanated from anode tip.
Enhancement of X-ray emission in the side on direction in a Mather-type plasma focus
The European Physical Journal D, 2006
A 1.8 kJ Mather-type plasma focus (PF) for argon and hydrogen filling is examined. Two anode configurations are used. One is tapered towards the anode face, and the other is cylindrical but the face is cut at different angles. At optimum conditions, the system is found to emit Cu-Kα X-rays of about 1.6 ± 0.1 J/sr in the side-on direction for argon filling, which is about 32% of the total X-ray emission. In 4π-geometry, maximum total X-ray yield and wall plug efficiency found are 26.4 ± 1.3 J and 1.5 ± 0.1% respectively. The modified geometry may help to use the PF as a radiation source for X-ray diffraction.
Low-Energy Plasma Focus as a Tailored X-Ray Source
Journal of Fusion Energy, 2000
A low-energy (2.3 kJ) plasma focus energized by a single 32-μF capacitor charged at 12 kV with filling gases hydrogen, neon, and argon is investigated as an X-ray source. Experiments are conducted with a copper and an aluminum anode. Specifically, attention is given to tailoring the radiation in different windows, e.g., 1.2–1.3 keV, 1.3–1.5 keV, 2.5–5 keV, and Cu-Kα line radiation. The highest X-ray emission is observed with neon filling and the copper anode in the 1.2–1.3 keV window, which we speculate to be generated due to recombination of hydrogenlike neon ions with a few eV to a few 10s of eV electrons. The wall-plug efficiency of the device is found to be 4%. The other significant emission occurs with hydrogen filling, which exhibits wall-plug efficiency of 1.7% for overall X-ray emission and 0.35% for Cu-Kα line radiation. The emission is dominated by the interaction of electrons in the current sheath with the anode tip. The emission with the aluminum anode and hydrogen filling is up to 10 J, which corresponds to wall-plug efficiency of 0.4%. The X-ray emission with argon filling is less significant.
X-ray Emission from Plasma Focus: Envisioned by Various Competitive Detectors
Journal of Fusion Energy, 2008
A study of X-ray emission from a Mather-type plasma focus device by simultaneously employing various X-ray detectors like silicon pin diode, photoconducting detectors (PCDs)-CVD-diamond and gallium arsenide (GaAs), plastic scintillator coupled with photomultiplier tube with and with out optical fiber is presented. The pin diode and PCDs are masked with 10 lm thick cobalt filter. The device is energized by 9 lF capacitor bank charged at 18 kV (1.45 kJ), giving a peak discharge current of about 175 kA, with hydrogen as the filling gas. The optical fiber coupling is found to be beneficial in minimizing the electromagnetic noise generated during the system operation.
Indian Journal of Physics, 2013
Radiation emission in a 2.2 kJ Mather-type plasma focus device is investigated using a five channel BPX65 PIN diode spectrometer. At optimum condition, radiation emission from the system is found to be strongly influenced in hollow anode and filling gas pressure. Maximum X-ray yield in 4p sr has been obtained in case of hollow anode in argon gas medium due to interaction of electron beam. Results indicate that an appropriate design of anode can enhance radiation emission by more intense interaction of expected electron beam with hollow anode. The outcome is helpful to design a plasma focus with enhanced X-ray generation with improved shot-to-shot reproducibility in plasma focus device.
Generation of titanium K-radiation in a 1 kJ plasma focus
Plasma Devices and Operations, 2004
Titanium K-series line radiation emission from a low energy Mather-type plasma focus operated with hydrogen was investigated by employing Quantrad Si pin diodes as time resolved X-ray detectors. It has the highest value of 1.6 + 0.1 J in 4p-geometry, and the corresponding machine efficiency is about 0.16 + 0.01%. The total X-ray emission is about 3.2 + 0.2 J, and the corresponding machine efficiency is about 0.32 + 0.02%. The Ti K-line radiation emission may result from the interaction of energetic electron beam emitted from the focus region, and the energetic electrons in the current sheath, with the anode tip.
Plasma focus as a possible x-ray source for radiography
Plasma Sources Science & Technology, 2005
The performance of a low energy (0.6-1.8 kJ) Mather-type plasma focus (PF) device as a Cu-K α x-ray source is examined. The Cu-K α and total x-ray emissions are measured for argon and hydrogen filling. It is found that
Variation of Radiation Emission with Argon Gas Pressure in UM Plasma Focus with the Hollow Anode
A Plasma Focus device (2.2 kJ, 12 kV) is studied as a pulsed X-ray source, operated with Argon at a filling pressure in the range of 0.7 to 2.5 mbar. The time resolved X-ray signals are measured with an array of PIN diode detectors. The X-ray emission produced by the plasma focus discharge at various pressures is investigated and compared. It is found that at the high pressure regime of more than 1.5 mbar, very consistent and high output of X-ray radiation is obtained, at the peak of the discharge current. A remarkable increase of about five times of the average X-ray yield is achieved at optimum pressure 1.7 mbar compared to that obtained at other pressures. An indirect method to determine the electron temperature of the plasma is achieved by using the array of 5 channel PIN diode detector coupled with Al foil of different thicknesses. The result shows that the electron temperature of the plasma is 7 keV, when the operating pressure is at 1.7 mbar. The maximum total X-ray yield is about 2.53 mJ per shot at optimum pressure, equivalent to the efficiency of 0.00012%.
Soft X-Ray Emission in the (1.0-1.5 keV) Window with Nitrogen Filling in a Low Energy Plasma Focus
Modern Physics Letters B, 2002
A study of soft X-ray emission in the 1.0-1.5 keV energy range from a low energy (1.15 kJ) plasma focus has been conducted. X-rays are detected with the combination of Quantrad Si PIN-diodes masked with Al (50 μm), Mg (100 μm) and Ni (17.5 μm) filters and with a pinhole camera. The X-ray flux is found to be measurable within the pressure range of 0.1-1.0 mbar nitrogen. In the 1.0-1.3 keV and 1.0-1.5 keV windows, the X-ray yield in 4π-geometry is 1.03 J and 14.0-J, respectively, at a filling pressure of 0.25 mbar and the corresponding efficiencies are 0.04% and 1.22%. The total X-ray emission in 4π-geometry is 21.8 J, which corresponds to the system efficiency of about 1.9%. The X-ray emission is found dominantly as a result of the interaction of energetic electrons in the current sheath with the anode tip. Images recorded by the pinhole camera confirm the emission of X-rays from the tip of the anode.
X-ray enhancement from a plasma focus by inserting lead at the anode tip
Physics Letters A, 2003
Study of X-ray emission from a low-energy (1.8 kJ) plasma focus device powered by a 9 µF capacitor bank, charged at 20 kV and giving peak discharge current of about 175 kA by using lead inserted copper tapered anode is reported. The X-ray yield in different energy windows is measured as a function of hydrogen filling pressure. The maximum yield in 4π-geometry is found to be 27.3 ± 1.1 J and corresponding wall plug efficiency for X-ray generation is 1.52 ± 0.06%. The feasibility of the device as an intense X-ray source for radiography is demonstrated.