Narrow bandwidth, low-emittance positron beams from a laser-wakefield accelerator

• Published in: Scientific reports Vol. 14; no. 1; p. 6001
• Main Authors: Streeter, M. J. V., Colgan, C., Carderelli, J., Ma, Y., Cavanagh, N., Los, E. E., Ahmed, H., Antoine, A. F., Audet, T., Balcazar, M. D., Calvin, L., Kettle, B., Mangles, S. P. D., Najmudin, Z., Rajeev, P. P., Symes, D. R., Thomas, A. G. R., Sarri, G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12-03-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/1960; 639/766/1960/1135; 639/766/25; Energy charge; Experimental research; Humanities and Social Sciences; Lasers; multidisciplinary; Positrons; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-56281-1

The rapid progress that plasma wakefield accelerators are experiencing is now posing the question as to whether they could be included in the design of the next generation of high-energy electron-positron colliders. However, the typical structure of the accelerating wakefields presents challenging complications for positron acceleration. Despite seminal proof-of-principle experiments and theoretical proposals, experimental research in plasma-based acceleration of positrons is currently limited by the scarcity of positron beams suitable to seed a plasma accelerator. Here, we report on the first experimental demonstration of a laser-driven source of ultra-relativistic positrons with sufficient spectral and spatial quality to be injected in a plasma accelerator. Our results indicate, in agreement with numerical simulations, selection and transport of positron beamlets containing
N
e
+
≥
10
5
positrons in a 5% bandwidth around 600 MeV, with femtosecond-scale duration and micron-scale normalised emittance. Particle-in-cell simulations show that positron beams of this kind can be guided and accelerated in a laser-driven plasma accelerator, with favourable scalings to further increase overall charge and energy using PW-scale lasers. The results presented here demonstrate the possibility of performing experimental studies of positron acceleration in a laser-driven wakefield accelerator.