Radiation losses in a dense high-temperature hydrogen plasma containing impurities

The authors calculate the radiation intensity of a hydrogen plasma containing small amounts of impurity in the form of bare nuclei and hydrogen-, helium-, lithium- and beryllium-like ions with a nuclear charge Z in the range 5 ≤ Z ≤ 18. They consider electron concentrations of 10 16 ≤ n e ≤ 10 20 cm −3 and electron temperatures of 0.05 ⩽ kT/Z 2 Ry ⩽ 3 (Ry = 13.6eV), which are typical of the radiating zone of the plasma focus. The results show, among other things, that the radiation from the impurities may substantially limit the life-time of the high-temperature zone in the plasma focus.