Comparison of experimental data and 3D simulations of ion beam neutralization from the neutralized transport experiment

Journal Article · Wed Sep 22 04:00:00 EDT 2004 · Physics of Plasmas

OSTI ID:838982

Thoma, C ^[1]; Welch, D R; Yu, S S; Henestroza, E; Roy, P K; Eylon, S; Gilson, E P

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1. LBNL Library

The Neutralized Transport Experiment (NTX) at Lawrence Berkeley National Laboratory has been designed to study the final focus and neutralization of high perveance ion beams for applications in heavy ion fusion (HIF) and high energy density physics (HEDP) experiments. Pre-formed plasmas in the last meter before the target of the scaled experiment provide a source of electrons which neutralize the ion current and prevent the space-charge induced spreading of the beam spot. NTX physics issues are discussed and experimental data is analyzed and compared with 3D particle-in-cell simulations. Along with detailed target images, 4D phase-space data of the NTX at the entrance of the neutralization region has been acquired. This data is used to provide a more accurate beam distribution with which to initialize the simulation. Previous treatments have used various idealized beam distributions which lack the detailed features of the experimental ion beam images. Simulation results are compared with NTX experimental measurements for 250 keV K{sup +} ion beams with dimensionless perveance of 1-7 x 10{sup -4}. In both simulation and experiment, the deduced beam charge neutralization is close to the predicted maximum value.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Office of Fusion Energy Sciences (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 838982
• Report Number(s): LBNL--56401; HIFAN 1371
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Vol. 12
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DISTRIBUTION
ELECTRONS
ENERGY DENSITY
HEAVY IONS
ION BEAMS
PHASE SPACE
PHYSICS
SIMULATION
SPACE CHARGE
TARGETS
TRANSPORT