Enhanced laser-driven proton acceleration via improved fast electron heating in a controlled pre-plasma

L. A. Gizzi; E. Boella; L. Labate; F. Baffigi; P. J. Bilbao; F. Brandi; G. Cristoforetti; A. Fazzi; L. Fulgentini; D. Giove; P. Koester; D. Palla; P. Tomassini

doi:10.1038/s41598-021-93011-3

arXiv · 2106.00814

Enhanced laser-driven proton acceleration via improved fast electron heating in a controlled pre-plasma

L. A. Gizzi·E. Boella·L. Labate·F. Baffigi·P. J. Bilbao·F. Brandi·G. Cristoforetti·A. Fazzi·L. Fulgentini·D. Giove·P. Koester·D. Palla·P. Tomassini

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Abstract

The interaction of ultraintense laser pulses with solids is largely affected by the plasma gradient at the vacuum-solid interface, which modifies the absorption and ultimately, controls the energy distribution function of heated electrons. A micrometer scale-length plasma has been predicted to yield a significant enhancement of the energy and weight of the fast electron population and to play a major role in laser-driven proton acceleration with thin foils. We report on recent experimental results on proton acceleration from laser interaction with foil targets at ultra-relativistic intensities. We show a three-fold increase of the proton cut-off energy when a micrometer scale-length pre-plasma is introduced by irradiation with a low energy femtosecond pre-pulse. Our realistic numerical simulations agree with the observed gain of the proton cut-off energy and confirm the role of stochastic heating of fast electrons in the enhancement of the accelerating sheath field.

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L. A. Gizzi, E. Boella, L. Labate, F. Baffigi, P. J. Bilbao, F. Brandi, G. Cristoforetti, A. Fazzi, L. Fulgentini, D. Giove, P. Koester, D. Palla, P. Tomassini. 2021-06-01. Enhanced laser-driven proton acceleration via improved fast electron heating in a controlled pre-plasma. https://doi.org/10.1038/s41598-021-93011-3

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