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

POSTER

Abstract

Plasmas are a source of unbound electrons for neutralizing heavy ion beams to focus their radial and compress their axial dimensions to achieve high intensity beams for warm dense matter experiments. Long metal plasma columns are produced by the ferroelectric ceramic, BaTiO$_{3}$. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) is covered with ceramic material. High voltage ($\sim $ 8 kV) is applied across the ceramics. A BaTiO$_{3}$ source comprised of five 20-cm-long sources produced uniform plasma in the 5x10$^{10}$ cm$^{-3}$ density range and was used to achieve high beam compression ratios on NDCX. The source was extended to 2 meters and resulted in the heavy ion beam density increasing from 2x10$^{8}$ to 7x10$^{11}$ cm$^{-3}$ and reducing the spot size to 1.5 mm. Present research is developing higher density sources by examining smaller diameter ferroelectric sources and flashboard circuits. A ferroelectric source of 2.9 cm ID achieved densities of 6x10$^{11}$ cm$^{-3}$. Flashboards have the potential to achieve densities approaching 10$^{13}$ cm$^{-3}$.

*Work Supported by US Department of Energy.

Authors

  • P.C. Efthimion

    • Plasma Physics Laboratory, Princeton University, Princeton, NJ

  • Erik Gilson

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

  • Ronald Davidson

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

  • B.G. Logan

    • Lawrence Berkeley National Laboratory, University of California, Berkeley, CA
    • LBNL

  • Peter A. Seidl

    • Lawrence Berkeley National Laboratory, University of California, Berkeley, CA
    • Lawrence Berkeley National laboratory

  • William L. Waldron

    • Lawrence Berkeley National Laboratory, University of California, Berkeley, CA
    • LBNL
    • Lawrence Berkeley National laboratory