Radiative collapses in Z-pinches with axial mass losses

The possibility of producing radiative collapses in pinches is studied using a 1/2D numerical model with pure bremsstrahlung as the source of radiation, including anomalous resistivities and axial mass losses. The results of the model show the existence of both a lower and an upper limit value of the pinch current to produce collapses. It is also shown that a minimum initial pinch radius (which depends on the initial particle density) is required in order to obtain radiative collapses. The inclusion of axial mass losses makes the production of the collapse more difficult, because it enhances the anomalous resistivity heating. (author)