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arXiv · 2009.05521

Ultra-short, MeV-scale laser-plasma positron source for positron annihilation lifetime spectroscopy

Thomas L. Audet·Aaron Alejo·Luke Calvin·Mark Hugh Cunningham·Glenn Ross Frazer·Nasr A. M. Hafz·Christos Kamperidis·Song Li·Gagik Nersisyan·Daniel Papp·Michael Phipps·Jonathan Richard Warwick·Gianluca Sarri
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Abstract

Sub-micron defects represent a well-known fundamental problem in manufacturing since they can significantly affect performance and lifetime of virtually any high-value component. Positron annihilation lifetime spectroscopy is arguably the only established method capable of detecting defects down to the sub-nanometer scale but, to date, it only works for surface studies, and with limited resolution. Here, we experimentally and numerically show that laser-driven systems can overcome these well-known limitations, by generating ultra-short positron beams with a kinetic energy tuneable from 500 keV up to 2 MeV and a number of positrons per shot in a 50 keV energy slice \color{black} of the order of $10^3$. Numerical simulations of the expected performance of a typical mJ-scale kHz laser demonstrate the possibility of generating MeV-scale narrow-band and ultra-short positron beams with a flux exceeding $10^5$ positrons/s, of interest for fast volumetric scanning of materials at high resolution.

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Thomas L. Audet, Aaron Alejo, Luke Calvin, Mark Hugh Cunningham, Glenn Ross Frazer, Nasr A. M. Hafz, Christos Kamperidis, Song Li, Gagik Nersisyan, Daniel Papp, Michael Phipps, Jonathan Richard Warwick, Gianluca Sarri. 2020-09-11. Ultra-short, MeV-scale laser-plasma positron source for positron annihilation lifetime spectroscopy. https://doi.org/10.1103/physrevaccelbeams.24.073402

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