High-charge, highly polarized positron beams generated from a laser-driven nanowire-array target
Abstract
The generation of high-charge, highly polarized positron beams in the interaction of a linearly polarized laser pulse with a nanowire-array target is investigated. Here, laser-driven electrons emit high-energy photons through nonlinear Compton scattering (NCS), which subsequently produce electron--positron pairs through the nonlinear Breit--Wheeler (NBW) process. We model this interaction using two-dimensional spin-resolved quantum electrodynamics particle-in-cell (QED-PIC)} simulations. At positron birth, the sign of Sz is statistically correlated with that of the local Bz. The spatiotemporal field structure arising from the laser--nanowire interaction strengthens the correlation between the birth spin sign and the direction of the subsequent transverse Lorentz impulse, thereby limiting cancellation between opposite-spin contributions at a given angle. The results show that the average polarization degree reaches |S̅z|≈0.46, and the positron charge satisfying |S̅z|>0.3 is approximately 308 nC. Parameter scans reveal that the high-polarization positron charge is maximized at intermediate target densities and nanowire periods. Such a source could enable polarization-sensitive studies of strong-field QED and spin-dependent phenomena in high-energy and materials physics.
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BibTeX
@misc{zhang2026highcharge,
title = {{High-charge, highly polarized positron beams generated from a laser-driven nanowire-array target}},
author = {De-Sheng Zhang and Cui-Wen Zhang and Kun Xue and Feng Wan and Xue-Ren Hong and Jian-Xing Li and Bai-Song Xie},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.09908},
eprint = {2609.09908},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.09908},
}
RIS
TY - UNPB
TI - High-charge, highly polarized positron beams generated from a laser-driven nanowire-array target
AU - De-Sheng Zhang
AU - Cui-Wen Zhang
AU - Kun Xue
AU - Feng Wan
AU - Xue-Ren Hong
AU - Jian-Xing Li
AU - Bai-Song Xie
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.09908
UR - https://arxiv.org/abs/2609.09908
AB - The generation of high-charge, highly polarized positron beams in the interaction of a linearly polarized laser pulse with a nanowire-array target is investigated. Here, laser-driven electrons emit high-energy photons through nonlinear Compton scattering (NCS), which subsequently produce electron--positron pairs through the nonlinear Breit--Wheeler (NBW) process. We model this interaction using two-dimensional spin-resolved quantum electrodynamics particle-in-cell (QED-PIC)} simulations. At positron birth, the sign of S_z is statistically correlated with that of the local B_z. The spatiotemporal field structure arising from the laser--nanowire interaction strengthens the correlation between the birth spin sign and the direction of the subsequent transverse Lorentz impulse, thereby limiting cancellation between opposite-spin contributions at a given angle. The results show that the average polarization degree reaches |S̅_z|≈0.46, and the positron charge satisfying |S̅_z|>0.3 is approximately 308 nC. Parameter scans reveal that the high-polarization positron charge is maximized at intermediate target densities and nanowire periods. Such a source could enable polarization-sensitive studies of strong-field QED and spin-dependent phenomena in high-energy and materials physics.
ER -