1–6 Jun 2025
Taipei International Convention Center (TICC)
Asia/Taipei timezone

Improvement of electron beam properties for Few-TW LWFA conducted in a sub-mm gas cell filled with a helium-nitrogen mixture

TUPS134
3 Jun 2025, 16:00
2h
Exhibiton Hall A _Salmon (TWTC)

Exhibiton Hall A _Salmon

TWTC

Poster Presentation MC3.T25 Lasers Tuesday Poster Session

Speaker

Po Wei Lai (National Tsing Hua University)

Description

Developing a laser wakefield acceleration (LWFA) scheme by focusing few-TW laser pulses into a thin, dense gas target paves the way for generating high-average-current electron beams driven by a modern high-repetition-rate laser. Our previous study demonstrated that using a sub-mm nitrogen (N₂) gas cell facilitates the routine generation of 10-MeV-scale electron beams from few-TW LWFA with ionization-induced injection. However, excessive ionization-induced defocusing of the pump laser pulse tends to occur in an N₂ target, motivating the use of a helium (He) – nitrogen (N₂) mixture as the gas target to mitigate pump pulse defocusing in few-TW LWFA*. In this study, the effect of nitrogen doping ratio ranging from 0.5% to 5% was investigated using 40-fs, 1-TW pulses with a 0.4-mm-long gas cell. We found that a manifest peak repeatedly appears around 10 MeV in the energy spectra with the 99.5% He - 0.5% N₂ gas mixture - a result never observed with the pure N₂ cell. Using the He-N₂ mixture also leads to a noticeable increase in the charge of high-energy electrons (>5 MeV) and a reduction in the pointing fluctuation of the output beams compared to the pure N₂ target.

Funding Agency

This work was supported by the National Science and Technology Council in Taiwan with Grant No. NSTC 113-2112-M-007-013 and NSTC 113-NU-E-007-006-NU.

Footnotes

P. -W. Lai et al., Phys. Plasmas, 30, 010703 (2023).
*M. -W. Lin et al., Phys. Plasmas, 27, 013102 (2020).

Region represented Asia
Paper preparation format Word

Author

Po Wei Lai (National Tsing Hua University)

Co-authors

Chen-Kang Huang (National Central University) Chih-Hao Pai (National Central University) Hsu-hsin Chu (National Central University) Khoa Tran (National Tsing Hua University) Ming-wei Lin (National Tsing Hua University) Shih-Hung Chen (National Central Univeristy) Yao-Li Liu (National Central University)

Presentation materials

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