Status on the Sphinx Machine Based on the I-as LTD Technology

The Sphinx machine developed at the Centre d'Etudes de Gramat is based on the 1-μs linear-transformer-driver (LTD) technology. Before 2006, it operated with 16 branches of eight LTD stages each and was used for implosion of Z-pinch loads in direct drive mode. At a charging voltage of 50 kV, the stored energy was 1.3 MJ, and the good reliability of the machine allowed many experiments on 4-MA 700-ns implosion of nested wire arrays. Parallel to these experiments, improvements on LTD stages have been achieved on test beds up to 70-kV charging voltage, leading to a new design of LTD stage, named LTD-05. The Sphinx machine has been upgraded with 144 such LTD-05 stages. Details are given on stage design, on electrical and electrostatic simulations, and on experimental results. The following subsystems modifications or developments are also described: 1) premagnetizing and triggering systems and 2) prepulse current generator for wire-array preheating. Moreover, a status on improved performances and reliability of the complete Sphinx system is given.