Design analysis on composite target of high energy multi-pulse radiography

The analytic theory of the energy deposition of electron beam on the conversion target and the design approach for the composite target are presented. The high temperature plasma formed in the simple target would eject along positive and negative axial directions and make the target perforated. In the same beam energy, the beam with larger focal spot makes smaller ablated cavities with curl edge in the target, but the beam with smaller spot makes larger ones with relativly smooth edge. The composite target and the modified composite target can bear continuous strikes of 2~3 beam pulses. The Monte Carlo simulation shows that the spot size of bremsstrahlung sources are the same as the electron beam spot size on the target, thus the composite target can be used in the multi-pulse radiograph