Hydrodynamic Expansion of Pellicles Caused by e-Beam Heating

Ho, D.

Lawrence Livermore National Laboratory

关键词: Heating;    X-Ray Radiography;    Computerized Simulation;    43 Particle Accelerators;    36 Materials Science;   

DOI  :  10.2172/792635
RP-ID  :  UCRL-ID-137358
RP-ID  :  W-7405-Eng-48
RP-ID  :  792635

美国|英语

来源: UNT Digital Library

【 摘 要 】

Placing a pellicle in front of a x-ray converter target for radiographic applications can confine the backstreaming ions and target plasma to a shorter channel so that the cumulative effect on e-beam focusing is reduced. The pellicle is subject to heating by e-beam since the pellicle is placed upstream of the target. The calculation of the hydrodynamic expansion, caused by the heating, using the radiation hydrodynamics code LASNEX is presented in this report. Calculations show that mylar pellicles disintegrate at the end of a multi-pulse intense e-beam while beryllium and carbon pellicles remain intact. The expansions for the kapton-carbon multi-layered targets are also examined. Hydrodynamic expansions for pellicles with various e-beam spot radii are calculated for DARHT-II beam parameters. All the simulation results indicate that the backstreaming ions can be stopped.