Computer assisted beam characterization at AIRIX facility

AIRIX is a high current accelerator designed for flash X-ray radiography. The electron beam produced into a vacuum diode (2 kA, 3.5 MV to 3.8 MV, 60 ns) is extracted from a velvet cold cathode. For a complete beam characterization, at the diode output, a set of beam transport data is required. Part of those parameters can be experimentally obtained, but others, the transverse beam sizes, are unfortunately not measured. The TRAJENV code is designed to simulate beam transport. The code is coupled with the MINUIT minimization library and it computes the unknown beam parameters at the diode output. In this paper, we propose to describe both experimental and theoretical approaches leading to the full beam characterization at the diode output.