Positron acceleration by terahertz wave and electron beam in plasma channel

• Published in: New journal of physics Vol. 25; no. 6; pp. 63013 - 63019
• Main Authors: Xu, Zhangli, Shen, Baifei, Si, Meiyu, Huang, Yongsheng
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.06.2023
• Subjects: coherent transition radiation; Defocusing; Electron beams; Electrons; intense terahertz wave; Metal foils; particle-in-cell (PIC) simulation; Physics; positron acceleration; Positrons; Terahertz frequencies
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/acdc47

Abstract We present a scheme of positron acceleration by intense terahertz (THz) wave together with the driving large-charge electron beam in a plasma channel. The THz wave rapidly evolves into a transversely uniform acceleration field and a weakly focusing/defocusing lateral field in the channel. The THz wave is partially formed with the scheme of coherent transition radiation when the electron beam goes through a metal foil and partially because of the wakefield in the plasma channel. The electron beam continuously supplies energy to the THz wave. Such a field structure offers the feasibility of long-distance positron acceleration while preserving beam quality. By two-dimensional simulations, we demonstrate the acceleration of positrons from initial 1 GeV to 126.8 GeV with a charge of ∼10 pC over a distance of 1 m. The energy spread of accelerated positrons is 2.2%. This scheme can utilize the electron beam either from laser-driven or conventional accelerators, showing prospects towards high-quality and flexible THz-driven relativistic positron sources of ∼100 GeV.