Design of a Radio-Frequency Accelerator Demonstrator for Driving X-Ray Source

Abstract

The assembly of a laser driven photo-injector and an RF linear accelerator offers the advantage of a versatile machine in order to produce multi-pulse electron beams. A train of 20 bunches (micro-pulses) carrying each a 100 nC charge would be extracted from a photo-cathode and accelerated in a DC voltage to 2.5 MV. The electron beam is then injected into superconducting radio frequency cavities operating at 352 MHz. They accelerate the beam as a relativistic linear accelerator. The 55 ns pulse duration electron beam (macro-pulse) is accelerated at 51 MeV through this structure. If this process is repeated at short given time delays, it enables to deliver multi-pulse or/and multi-axe electron beams. This machine has been proposed for radiographic applications and a design has been completed. It led to a proposal for a demonstrator of photo-injector which would be built shortly. Detailed simulations of the electron beam generation, acceleration and transport will be presented along with present experimental studies for validations of the numerical simulation codes.