Miniature plasma focus device as a portable hard x-ray source for fast radiography applications

Summary form only given. A table top miniature plasma focus device FMPF-1 has been successfully used as a portable, pulsed hard X-ray source for fast radiography applications. It has 2.4 muF capacitor bank formed by 4 capacitors, operates at _14 kV charging voltage and delivers ~80 kA peak discharge current in a quarter time period of ~400 ns. The system operates with deuterium gas in the filling gas pressure range of 4 to 9 mbar. The overall dimensions of the apparatus, which includes capacitor bank, sparkgap switch and the focus chamber is 0.2 m x 0.2 m x 0.5 m and the total mass of the system is ~25 kg. The radiation monitored using a photomultiplier tube coupled with NE102A plastic scintillator showed that hard X-ray pulse duration is ~25 ns full width at half maximum, thus allowing for fast imaging. Short pulse duration is of critical importance for resolving fast transient events. The experimental estimation of the effective average energy of the X-ray beam, without using any high-Z insert in stainless steel anode is found to be in the range of 40-50 keV. This value is compatible with that expected from the pinch induced voltage, evaluated using a validated numerical model. The hard X-ray radiation flux in the end-on direction has been found to be high enough for obtaining high contrast radiographs on commercially available general purpose medical X-ray film along with Konica Minolta KR-II intensifying screen. Standard developer and fixer were used for processing the film. Visibility of submilimetric details obtained in the radiographs demonstrates the suitability of the miniature plasma focus device as hard X-ray source for introrespective imaging of metallic objects. Developed system meets the fast radiography application need, in terms of performance, physical size, cost and ruggedness. Further investigation and optimization of the device to be used portable radiographic source for non-destructive testing applications using high-Z inserts is underway.