Europhys. Lett.
Volume 73, Number 1, January 2006
Page(s) 42 - 48
Section Physics of gases, plasmas and electric discharges
Published online 02 December 2005
Europhys. Lett., 73 (1), pp. 42-48 (2006)
DOI: 10.1209/epl/i2005-10364-y

Enhanced and reproducible X-ray emission in a low-energy plasma focus

S. Ahmad1, M. Sadiq1, S. Hussain1, M. Shafiq1, P. Lee2, M. Zakaullah1 and A. Waheed3

1  Department of Physics, Quaid-i-Azam University - 45320 Islamabad, Pakistan
2  Natural Sciences Academics Group, National Institute of Education, Nanyang Technological University - 1 Nanyang Walk, 637616, Singapore
3  PINSTECH - P.O. Box 1331, 44000 Islamabad, Pakistan

received 21 July 2005; accepted in final form 2 November 2005
published online 2 December 2005

The effect of pre-ionization by a shunt resistor on X-ray emission performance from a low-energy (2.7$\un{kJ}$) plasma focus is investigated by employing time-resolved and time- integrated detectors. Different shunt resistors are employed and 71$\un{M}$$\Omega$ is found the most appropriate in this experiment. It is estimated that with pre-ionization 49.56$\un{J}$ of energy is radiated as X-rays, out of which 21.5$\un{J}$ is in the form of $\chem{Cu}$-$K_\alpha$ lines in 4$\pi
$-geometry. The pre-ionization enhances the X-ray yield, broadens the working gas pressure range and improves the shot-to-shot reproducibility of the system. The pinhole images of X-ray-emitting zones indicate that the dominant X-ray emission is from the anode tip, although the emission from hot spots along the pinch axis also contributes.

52.59.Hq - Dense plasma focus.
52.58.Lq - Z-pinches, plasma focus, and other pinch devices.

© EDP Sciences 2005