Terahertz laser modulation of electron beams

Journal Article · Sun Mar 01 04:00:00 EST 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3075563· OSTI ID:21190052

Neumann, J G; Fiorito, R B; O'Shea, P G ^[1]; Loos, H; Sheehy, B; Shen, Y; Wu, Z ^[2]

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1. Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)
2. National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

The study of modulated electron beams is important because they can be used to produce coherent radiation, but the modulations can cause unwanted instabilities in some devices. Specifically, in a free electron laser, proper prebunching at the desired emission frequency can enhance performance, while bunching resulting from instabilities and bunch compression schemes can degrade performance. In a photoinjector accelerator, tailoring the shape of the drive laser pulse could be used as a technique to either enhance or mitigate the effect of these modulations. This work explores the possibility of creating deeply modulated electron beams at the photocathode by using a modified drive laser designed to produce multiple subpicosecond pulses repeated at terahertz frequencies. Longitudinal space charge forces can strongly influence the evolution of modulations by converting density modulations to energy modulations. Experiments at the Source Development Laboratory electron accelerator at Brookhaven National Laboratory and PARMELA simulations are employed to explore the dynamics of electron beams with varying charge and with varying initial modulation. Finally, terahertz light generated by a transition radiator is used to confirm the structure of the electron beam.

• OSTI ID: 21190052
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 105; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATORS
BEAM BUNCHING
BNL
COHERENT RADIATION
ELECTRON BEAMS
ELECTRONS
FREE ELECTRON LASERS
MODULATION
PERFORMANCE
PHOTOCATHODES
PULSES
SIMULATION
SPACE CHARGE