Adaptive electron beam shaping using a photoemission gun and spatial light modulator
The need for precisely defined beam shapes in photoelectron sources has been well established. In this paper, we use a spatial light modulator and simple shaping algorithm to create arbitrary, detailed transverse laser shapes with high fidelity. We transmit this shaped laser to the photocathode of a high voltage dc gun. Using beam currents where space charge is negligible, and using an imaging solenoid and fluorescent viewscreen, we show that the resultant beam shape preserves these detailed features with similar fidelity. Next, instead of transmitting a shaped laser profile, we use an active feedback on the unshaped electron beam image to create equally accurate and detailed shapes. We demonstrate that this electron beam feedback has the added advantage of correcting for electron optical aberrations, yielding shapes without skew. The method may serve to provide precisely defined electron beams for low current target experiments, space-charge dominated beam commissioning, as well as for online adaptive correction of photocathode quantum efficiency degradation.
- Research Organization:
- Cornell University, Ithaca, NY (United States). Cornell Laboratory for Accelerator-Based Studies and Education.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC00039650; SC0003965
- OSTI ID:
- 1179916
- Alternate ID(s):
- OSTI ID: 1188409
- Journal Information:
- Physical Review Special Topics. Accelerators and Beams, Journal Name: Physical Review Special Topics. Accelerators and Beams Vol. 18 Journal Issue: 2; ISSN 1098-4402
- Publisher:
- American Physical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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