그림: The accelerating electrons radiate coherent THz emissions continuously along the laser propagation direction, resulting in broadband multi-mJ THz radiation in the far field.
초강력 레이저를 이용한 차세대 전자가속 방법 중 하나인 레이저 항적장 가속 (Laser wakefield electron acceleration, LWFA) 에서 발생하는 테라헤르츠파 (Terahertz, THz) 를 검출 및 특성을 분석한 논문으로 현재까지 측정된 LWFA 에서 발생한 THz 에너지 중 가장 강력한 4 mJ 의 THz 를 생성하였다. 이 연구성과는 기존에 연구되던 메커니즘과 다른 새로운 메커니즘으로 THz 파가 생성될 수 있다는 방안을 제시하였고 광학 분야의 권위지인 Light science & applications 2023년 2월호에 출판되었다. Light science & applications 은 2021년도 JCR에 따르면 JIF가 20.257로 광학 분야 101개 분야 중 3위 이다.
High-power terahertz radiation was observed to be emitted from a gas jet irradiated by 100-terawatt-class laser pulses in the laser-wakefield acceleration of electrons. The emitted terahertz radiation was characterized in terms of its spectrum, polarization, and energy dependence on the accompanying electron bunch energy and charge under various gas target conditions. With a nitrogen target, more than 4 mJ of energy was produced at <10 THz with a laser-to-terahertz conversion efficiency of ~0.15%. Such strong terahertz radiation is hypothesized to be produced from plasma electrons accelerated by the ponderomotive force of the laser and the plasma wakefields on the time scale of the laser pulse duration and plasma period. This model is examined with analytic calculations and particle-in-cell simulations to better understand the generation mechanism of high-energy terahertz radiation in laser-wakefield acceleration.
해외 기사 링크 :
https://www.eurekalert.org/news-releases/978888
https://phys.org/news/2023-02-laser-accelerated-electron-terahertz-emissions.html
