IDERIX : An 8 MV flash x-rays machine using a LTD design

Abstract

For future flash radiographic needs, 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 +/− 100 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 (50μm) allow reducing the losses and improving the performances of the generator. The insulation inside the stage will be done using dielectric oil.