Calculation of the temporal structure for a pulsed slow positron beam based on superconducting accelerator

H. Q. Zhang; P. Kuang; Y. H. Hu; F. Y. Liu; X. Z. Cao; B. Y. Wang; X. P. Li

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arXiv · 2609.36533

Calculation of the temporal structure for a pulsed slow positron beam based on superconducting accelerator

H. Q. Zhang·P. Kuang·Y. H. Hu·F. Y. Liu·X. Z. Cao·B. Y. Wang·X. P. Li

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Abstract

The development of superconducting accelerator (SCA) provides a novel approach to generating pulsed slow positron beams with high time resolution and high intensity. SCAs can produce electron beams with repetition frequencies on the order of MHz and pulse widths of less than 100 ps. A pulsed positron beam based on SCA can, to a certain extent, preserve the excellent temporal structure of the primary electron beam. However, thermalization, diffusion, and surface re-emission of positrons in the moderator will inevitably lead to time broadening of positron pulses. In this paper, a calculation model coupling Geant4 Monte Carlo simulations with positron diffusion theory is established to evaluate the effect of the positron moderation process on time broadening. After being moderated by a tungsten foil, the initial time broadening of the pulsed slow positron beam is approximately 320 ps. By combining the time broadening calculation of pulsed beam during its transport, it is expected that the pulsed slow positron beam generated by the SCA, can be directly applied to the measurement of positron annihilation lifetime.

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H. Q. Zhang, P. Kuang, Y. H. Hu, F. Y. Liu, X. Z. Cao, B. Y. Wang, X. P. Li. 2026-09-29. Calculation of the temporal structure for a pulsed slow positron beam based on superconducting accelerator. https://arxiv.org/abs/2609.36533

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