Microcharge neutralization transport experiments and simulations for ion-driven inertial confinement fusion

Technical Report · Tue Dec 31 04:00:00 EST 1996

OSTI ID:467866

Olson, C L; Hanson, D L; Poukey, J W ^[1]; Welch, D R ^[2]

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1. Sandia National Lab., Albuquerque, NM (United States)
2. Mission Research Corp., Albuquerque, NM (United States)

Space charge neutralization for intense beams for inertial confinement fusion is usually assumed to be perfect. However, small charge clumps in the beam will not be totally charge neutralized, and the residual net minimum potential set by electron trapping (e{phi} {approx} {1/2}m{sub e}v{sup 2}{sub i}, where m{sub e} is the electron mass and v{sub i} is the ion velocity) may lead to a substantial microdivergence. Experiments on the SABRE accelerator and simulations with the IPROP computer code are being performed to assess this mechanism. The authors have successfully created a 5 mrad beam on the SABRE accelerator, by expanding the beam (a process consistent with Liouville`s theorem) and, by passing the beam through a plate with pinholes, they have created low divergence beamlets to study this mechanism. Results clearly show: (1) at low pressures, trapping does neutralize the beamlets, but only down to e{phi} {approx} {1/2}m{sub e}v{sup 2}{sub i}; and (2) at higher pressures ({approx} 0.1-1 Torr), plasma shielding does remove the effect.

• Research Organization: Lawrence Berkeley Lab., CA (United States); Princeton Univ., NJ (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 467866
• Report Number(s): CONF-9509149--
• Country of Publication: Netherlands
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM EMITTANCE
BEAM NEUTRALIZATION
CHARGE DISTRIBUTION
FLUCTUATIONS
HEAVY IONS
I CODES
ION BEAMS
SPACE CHARGE
TRANSIENTS