Design and preliminary results of the IMA plasma focus experiment

The present paper describes the design, operation and characteristics of aton 1MA plasma focus device, which built in egypt at the plasma physics department, N.R.C., atomic energy authority. The main parts of the system are: the coaxial electrodes of mather type, the expansion chamber, the condenser bank of 75 kJ stored energy, the pressurized spark gap switches and Blumlein trigger system. Measurement of the breakdown voltage between plasma focus electrodes and discharge current, using half of the condenser bank, showed that, for Uc h = 32 kV, the discharge current was 0.5 Ma. In the discharge current and voltage traces a sharp drop in discharge current correspondingly to a sudden rise in voltage have been observed, which characterize the focus regime. Time structure of the x-ray emission measurements have been performed by means of scintillation detectors. by using a hydrogen gas the results showed that, the x-ray intensity is increased with increasing the hydrogen gas pressure. plasma sheath current density, J-Z distribution in axial direction during the acceleration phase of the discharge is studied, using a miniature Rogovsky coil. The results cleared that Jz is increased with the axial distance from breech to muzzle at different hydrogen gas pressures. 12 figs