SPECTROSCOPIC DIAGNOSIS OF THE TEMPERATURE PROFILE OF AN AL-MG Z-PINCH

We consider the question of how the temperature profile of a Z-pinch p lasma can be determined and/or constrained by the requirement that its observed ii-shell spectrum be replicated. As a case study we employ s patially integrated, time-resolved K-shell data obtained from the impl osion of 30-wire Al:Mg alloy arrays on the Saturn driver at Sandia Nat ional Laboratories. Given the measured pinch size, its K-shell power a nd line intensities are compared with the predictions of a collisional -radiative-equilibrium plasma model whose temperature profile is varie d in seeking agreement with the data. The Al data rules out a large ra nge of possible temperature profiles, but two quite different temperat ure distributions can both match the measurements. These are: a unifor m temperature, or, one with a sharply dropping temperature near the pi nch outer edge. However, the measured ratio of the Mg a resonance line s to those of Al, even though time-integrated, excludes the possibilit y of a uniform temperature distribution.