Speaker
Description
Idealized physics models of charged-particle beam transport predict beam distribution second moments and envelopes, but not the detailed beam structure. We combine experiment and simulation to explore the interplay of space charge and angular momentum with realistic beam distributions in a low-energy transport system. Our realistic phase-space distributions derive from direct experimental measurements near the beam source. The platform for this work is our Long Solenoid Experiment (LSE), a beamline designed to explore flat-to-round (FTR) and round-to-flat (RTF) beam transformations where space charge is a significant factor. Our transport system employs a thermionic electron gun, a slit mask, and a triplet of skew quadrupoles to generate and manipulate flat beams with emittance ratios up to 20:1. The triplet is followed by a long solenoid, and diagnostics include a sliding view-screen that enables detailed phase-space diagnostics over multiple plasma periods. We present particle-in-cell simulations initialized with phase-space distributions measured directly at the source. These simulations reproduce the experimental observations with high fidelity and reveal the sensitivity of the transverse beam dynamics to initial conditions and lattice parameters.
Work supported by USDOE under grant DESC0022009.
| Working group | WG5 |
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