Density profile measurements from a two-gun focus device

Summary form only given. The dynamics of the plasma evolution in a two-gun plasma focus device has been studied using laser shadowgraphy and laser interferometry. The experiments were carried out with a 700-kJ two-gun plasma focus device consisting of a pair of Mather-type coaxial electrodes connected muzzle to muzzle. The goal of the experiment was to study the density profiles in the plasma foci and the middle region in order to understand the formation of the plasma foci and their time evolution. The laser shadowgraphy was done with an XeCl excimer pumped dye laser system which operated at 550 nm with a pulse width of ~10 ns. The laser interferometry was carried out using a TEA-TEA oscillator-amplifier N₂-laser system at 337.1 nm wavelength and subnanosecond pulse width. The maximum electron density was ⩾2×10¹⁹ cm^-3, and the growth of hydrodynamic instabilities was observed