Plasma focus characteristics using stainless steel anode

Abstract

In a low energy (2.3 kJ) Mather-type plasma focus with stainless steel anode, neutron and x-ray emission is investigated by employing time-integrated and time resolved detectors. A neutron yield of 3.5 × 108 is observed, which is almost double the yield when a copper anode is used. It is speculated that a low sputtering yield of the anode material lowers the impurity concentration in the plasma and thus enhances the neutron yield. One may therefore conclude that a proper choice of electrode material is essential to achieve enhanced radiation yield from plasma focus devices. At a pressure of 2.0 mbar, the neutron yield is found to be the highest and almost isotropic. Further, multiple foci are also observed. The neutron fluence isotropy and the high yield are attributed to trapping of magnetic flux lines and of energetic deuterons between the two current sheaths.

Enhanced and reproducible neutron emission from a plasma focus with pre-ionization induced by depleted uranium (U238)

“…During the last few decades, attempts have been made to enhance neutron yield from a plasma focus by adjusting different parameters such as capacitor energy, operating voltage, circuit inductance, pressure of working gases, material and shape of electrodes, proper selection of the length of the anode and insulator and different machine parameters in addition to normal operating conditions [3][4][5][6][7][8][9][10][11][12]. Plasma focus pulsars are among the cheapest available neutron generators, with unique features of extremely short pulses (hundreds of nanoseconds) that suit a number of interesting applications.…”

Effect of anode shape on correlation of neutron emission with pinch energy for a 2.7kJ Mather-type plasma focus device

“…The performance of this device was found to be higher than any other PF apparatus, compared on the empirical scaling law of neutron yield versus pinch current. A remarkable sixfold increase in the average maximum total neutron yield, compared to the similar energy UNU-ICTP Plasma Focus device, 18 was achieved for deuterium at a relatively much higher filling gas pressure of 20 mbar by Koh et al 19 Zakaullah et al 20 reported an increased neutron yield by using stainless steel anode instead of copper anode in a low energy ͑2.3 kJ͒ plasma focus device. Neutron yield of 3.5ϫ 10 8 was recorded by employing time integrated and time resolved detectors, which was almost twice the yield obtained from Cu anode.…”

Preliminary plasma focus studies at ODAK-3K device using track detectors

“…For this reason, plenty of work has been done on theoretical and experimental dependencies of neutron yield. For instance, the configuration of device, insulator characteristics, shape of the central anode, amount of peak and pinch currents and pressure and voltage values play an important role in obtaining the maximum neutron yield [11][12][13]. Another important point is that spatial scattering of yields is changed by the above-mentioned parameters.…”