IDERIX: An 8MV Flash X-rays Machine using a LTD Generator Design

Summary form only given. For future hydrodynamic experiments, an 8 MV radiographic machine, IDERIX, will be developed for the CEA/PEM. This machine will be composed by ~80 super fast LTD (linear transformer driver) stages. The output voltage of each of these stages (100 kV -75 ns) will be inductively added along a ~20 m stepped magnetically insulated transmission line to deliver the power up to the beam diode. In each stage, 16 bricks, made with two 8 nF capacitors (that can be charged up to plusmn100 kV) and one multi-channels multi-gaps switch, are arranged in parallel (with a star pattern). The number of bricks is chosen to adapt the stage impedance to the diode impedance and operate the LTD generator close to matched mode. Moreover, new magnetic cores using a thinner ferromagnetic tape (50 mum) will allow reducing the losses and improving the performances of the generator. The insulation inside the stage will be done using dielectric oil. Downstream, the vacuum transmission line will be connected to a diode. The negative rod pinch diode geometry has been studied and tested at 6 MV on the ASTERIX generator since 2004. In 2006, a 2 meters MITL with the same geometry than the foreseen end of the future LTD generator, has been added to ASTERIX to mimic the power feed. Thus a dose of 70 rads at 1 m and a spot size of 2 mm (LANL/CEA definition) have been obtained. Simulations predict that those performances should increase at 8 MV and should satisfy die specification asked to IDERIX. A global description of the machine followed by an update on generator and diode studies will be proposed.