Multi- Meter-Long Plasma Source for Heavy Ion Beam Charge Neutralization

POSTER

Abstract

Plasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to focus them to a small spot size and compress their axial length. To produce long plasma columns, sources based upon ferroelectric ceramics with large dielectric coefficients have been developed. The source utilizes the ferroelectric ceramic BaTiO$_{3}$ to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) is covered with ceramic material. High voltage ($\sim $ 8 kV) is applied between the drift tube and the front surface of the ceramics. A BaTiO$_{3}$ source comprised of five 20-cm-long sources has been tested and characterized, producing relatively uniform plasma in the 5x10$^{10}$ cm$^{-3}$ density range. The source has been integrated into the NDCX device for charge neutralization and beam compression experiments. Initial beam compression experiments yielded current compression ratios $\sim $ 120. Recently, an additional 1 meter long source was fabricated to produce a 2 meter source for NDCX compression experiments. Present research is developing higher density sources to support beam compression experiments for high energy density physics applications.

Authors

  • Philip Efthimion

    Plasma Physics Laboratory, Princeton University, Princeton, NJ, Princeton Plasma Physics Laboratory

  • E.P. Gilson

    Plasma Physics Laboratory, Princeton University, Princeton, NJ

  • Ronald Davidson

    Princeton Plasma Physics Laboratory, PPPL, Plasma Physics Laboratory, Princeton University, Princeton, NJ

  • B.G. Logan

    Lawrence Berkeley National Laboratory University of California, Berkeley, CA

  • P.A. Seidl

    Lawrence Berkeley National Laboratory University of California, Berkeley, CA

  • W. Waldron

    Lawrence Berkeley National Laboratory University of California, Berkeley, CA