Abstract
When liners (hollow cylindrical shells) are imploded by the current of a pulsed generator, the density of particles and energy of the pinched plasma are largely determined by the implosion time (initial radial size) of the liner, which should be longer than the rise time of current through the liner. Due to the preliminary injection of plasma into the region of the liner load, the rise time of the current through the liner can be reduced to several nanoseconds, and the initial radius of the liner can be reduced to 1 mm or less. This approach makes it possible to obtain a plasma column with a particle density higher than the particle density in a solid, and a plasma energy density of more than 108 J/cm3already at a generator current of 1–2 MA. The spectrum of thermal X-ray emission from such a plasma can be close to the Planck spectrum, which makes it possible to determine the plasma temperature from the ratio of the signals of radiation sensors with different spectral responses. In this paper, under the assumption of the Planck radiation spectrum, the temperature dependence of the signal ratio of two photoemission X-ray diodes (XRDs) with an aluminum photocathodes and polypropylene filters 10 µm and 20 µm thick is calculated. The calculation results were used to determine the temperature of the pinched plasma in experiments on the implosion of thin aluminum foil liners.