Progress in light ion fusion

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5905322

Quintez, J P; Adams, R G; Allshouse, G O; Bacon, L D; Bailey, J E; Bloomquist, D D; Chandler, G A; Coats, R S; Cook, D L; Cuneo, M E; Derzon, M S; Desjarlais, M P; Dreike, P L; Dukart, R J; Gerber, R A; Green, T A; Haill, T A; Hanson, D L; Hussey, T W; Johnson, D J ; Kensek, R P; Kiefer, M L; Krall, N A; Leeper, R J; Lockner, T R; Maenchen, J E; Matzen, M K; McDaniel, D H; McGuire, E J; McKay, P F

Advances in ion beam theory, diagnostics, and experiments in the past two years have enabled efficient generation of intense proton beams on PBFA II and focusing of the beam power to 5.4 TW/cm{sup 2}. Improvements in the uniformity of the ion diode magnetic field and anode shaping produced a proton beam with good azimuthal symmetry. The beam was diagnosed using conical targets in concert with inner-shell excitation x-ray cameras and ion pinhole cameras. The measured asymmetry was less than 15 percent, a level adequate to begin initial studies of the beam/target interaction with proton beams. Substantial improvements in power density beyond the present level require an ion beam that is more magnetically stiff and has lower ion divergence. Thin-film-based lithium sources have produced more than 150 kJ of lithium energy above 6 MV. For the first 15 ns of the ion beam pulse, multiple diagnostics show a high purity lithium beam. Simulations using the three-dimensional electromagnetic particle-in-cell code QUICKSILVER have identified an early-time diocotron instability in the electron flow in the diode. Analytic calculations, which include a charge-neutral region in the diode inside the beam acceleration gap, give a growth rate for the diocotron instability that is in good agreement with the simulations. In the QUICKSILVER simulations, the early-time diocotron instability eventually gives way to a low-frequency instability with a period on the order of the ion beam transit-time'' time scale. When this occurs, the ion divergence increases substantially as a result of the enhanced coupling. Results from the ion diode simulations and analytic theory are discussed, as well as recent developments in diagnostics for the measurement of ion divergence.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5905322
• Report Number(s): SAND-91-0859C; CONF-9104210--2; ON: DE91010854
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700208* -- Fusion Power Plant Technology-- Inertial Confinement Technology
ACCELERATORS
BEAMS
CHARGED PARTICLES
FOCUSING
ION BEAM TARGETS
IONS
LIGHT IONS
LITHIUM IONS
NUCLEON BEAMS
PARTICLE BEAM FUSION ACCELERATOR
PARTICLE BEAMS
PLASMA DIAGNOSTICS
PROTON BEAMS
TARGETS