Thermal electric and magnetic fields at the surface of an electron beam target
A relativistic electron beam pulse of high current density will heat a thin target plate to a plasma state as it traverses. The gradient of plasma temperature--Te is predominantly radial, and the gradient of plasma density--ne is predominantly axial. The cross product of these terms is significant at the vacuum-to-metal interface through which the beam enters. This cross product is a thermal source of magnetization, which can be much larger than the vacuum magnetic field of the electron beam, and it is of opposite polarity. The thermal energy density in the target can be hundreds of times larger than the energy density of the vacuum magnetic field of the beam. If the nose of the electron beam current pulse rises linearly with time then the thermal magnetization increases as time squared. Heat pushes electrons axially from the interior of the plate to the surfaces, and radially away from the beam axis. The electric field that arises from this effect is essentially the negative of the pressure gradient, it points outward.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP) (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 9124
- Report Number(s):
- UCRL-JC-134513; YN0100000; YN0100000; TRN: AH200122%%257
- Resource Relation:
- Conference: ICOPS'99, The 26th IEEE International Conference on Plasma Science, Monterey, CA (US), 06/20/1999--06/24/1999; Other Information: PBD: 9 Jun 1999
- Country of Publication:
- United States
- Language:
- English
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