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With the rapid development of high-power petawatt class lasers worldwide, exploring physics in the strong field QED regime will become one of the frontiers for laser–plasma interactions research. Particle-in-cell codes, including quantum emission processes, are powerful tools for predicting and analyzing future experiments where the physics of relativistic plasma is strongly affected by strong field QED processes. The spin/polarization dependence of these quantum processes has been of recent interest. In this article, we perform a parametric study of the interaction of two laser pulses with an ultrarelativistic electron beam. The first pulse is optimized to generate high-energy photons by nonlinear Compton scattering and efficiently decelerate electron beam through the quantum radiation reaction. The second pulse is optimized to generate electron–positron pairs by the nonlinear Breit–Wheeler decay of photons with the maximum polarization dependence. This may be experimentally realized as a verification of the strong field QED framework, including the spin/polarization rates.
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Compact module for complementary-channel THz pulse slicing
We present a modular quasi-optical pulse slicer designed for use at terahertz (THz) frequencies. Given a quasi-cw input, the two outputs of a module are (1) a pulse with programmable duration and (2) its complement. The quasi-optical design incorporates a laser-driven silicon switch at Brewster's angle to the incoming THz beam, which limits undesired reflections before the switch is activated such that THz power is only transmitted when the switch is “on.” An “off” switch ensures that no power is leaked after the pulse and that the switching profile is sharp. The slicer's small footprint (0.048×0.072×0.162 m3) and small insertion loss (1.2 dB at 320 GHz) as well as high switching efficiency (∼70%) allows modules to be stacked to create multiple pulses. The output channel that is not used for experiments can be used for concurrent analysis of beam parameters. Stacking modular assemblies will enable more complex sequences of kW-level pulses than are currently achievable for applications including free-electron-laser or gyrotron-powered pulsed electron spin resonance at high magnetic fields.
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- Award ID(s):
- 2117994
- PAR ID:
- 10536586
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Applied Physics Letters
- Volume:
- 124
- Issue:
- 2
- ISSN:
- 0003-6951
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1063/5.0180412
