Terahertz Cherenkov radiation induced by a self-modulated electron beam in plasma wakefield

Shengpeng Yang,Changjian Tang,Yuxi Xia,Shaoyong Chen,Qing Zhou

doi:10.1063/1.5047253

Abstract

In this paper, a novel scheme of generating terahertz radiation is proposed, which considers a relativistic electron beam being modulated by its self-excited plasma wakefield in a plasma-filled slow-wave structure (SWS). Both the dispersion relation and the particle-in-cell simulation show that the self-modulation of the beam can act as a mode-selection method to excite the high-harmonics of the SWS and generate terahertz electromagnetic radiation. The present work gives a new thought for researching high-power and tunable terahertz sources.

Highlights

The past few years has witnessed a range of inspiring achievements in overcoming this challenge
The modulated beam will resonantly amplify the plasma wakefield in return
This positive feedback is known as the self-modulation instability,8–11 which is introduced in this paper as a mode-selection method scitation.org/journal/adv for exciting high-harmonic eigenmodes of a slow-wave structure (SWS)

Summary

INTRODUCTION

Terahertz (THz) band has drawn significant interests in many application areas including biomedical imaging, nondestructive testing, and high data rate communication. In the process of realizing these technologies, a great challenge is to find appropriate THz radiation sources. The past few years has witnessed a range of inspiring achievements in overcoming this challenge. In the process of realizing these technologies, a great challenge is to find appropriate THz radiation sources.. To make further efforts for designing more powerful and achievable THz sources, improvements on the present manufacturing technologies are needed, and more new techniques with innovative ideas are worthy to be explored. The modulated beam will resonantly amplify the plasma wakefield in return. This positive feedback is known as the self-modulation instability, which is introduced in this paper as a mode-selection method. As the mode-selection is determined by the plasma frequency, the electromagnetic (EM) radiation can reach the THz band by adjusting the plasma density

DISPERSION RELATION OF THE SYSTEM

Findings

PIC SIMULATION