Modeling the use of Self-Focused Beams to Overcome the Effects of Target Emissions in Advanced Hydrodynamic Radiography Machines

Lauer, E

Lawrence Livermore National Laboratory

关键词: Plumes;    71 Classical And Quantum Mechanics, General Physics;    Simulation;    Atomic Number;    Electron Beams;   

DOI  :  10.2172/15006181
RP-ID  :  UCRL-ID-143423
RP-ID  :  W-7405-ENG-48
RP-ID  :  15006181

美国|英语

来源: UNT Digital Library

【 摘 要 】

In the machines being developed for advanced hydrodynamic radiography, an electron beam of several kA current and 20 Mev particle energy is focused to less than a millimeter diameter onto a high atomic number target to produce bremstrahlung X-rays. Several pulses occur during a period of about 2 {micro}s. A plasma plume is predicted to move upstream from the target . If the final focus onto the target is in vacuum, then the plasma from an early pulse may neutralize the self-electric field of a later pulse causing over-focusing (1). Also positive ions may be accelerated upstream by the self-electric field of a beam focused onto a conducting target in vacuum (1,2). The ions neutralize part of the self-electric field and so cause a time varying change of focusing.