pISSN 0374-4914 eISSN 2289-0041

## Research Paper

New Phys.: Sae Mulli 2021; 71: 782-786

Published online September 30, 2021 https://doi.org/10.3938/NPSM.71.782

## Characteristics of Polarization Due to a Linearly Polarized Wiggler in a Free-electron Laser

Soon-Kwon NAM*, Yun Seong PARK

Department of Physics, Kangwon National University, Chunchon 24341, Korea

Correspondence to:snam@kangwon.ac.kr

Received: July 11, 2021; Revised: July 26, 2021; Accepted: July 26, 2021

### Abstract

We analyzed the characteristics of polarization due to a linearly polarized wiggler in a free-electron laser(FEL) oscillator and developed a three-dimensional free-electron laser code with a linearly polarized wiggler in a FEL oscillator for a wiggler period of 0.02 m, a wiggler length of 2 m, an electron beam energy of 13.40 MeV, and an electron beam current of 75 A. The total power due to the linearly polarized wiggler in the fundamental and higher-order modes was studied using the developed FEL code. The intensities of the radiation field with a linearly polarized wiggler for normalized emittances of 1, 5 and 10 mm$\cdot$mrad were calculated. Moreover, the intensity of radiation field with linearly polarized wiggler for the normalized emittances of 1mm$\cdot$mrad was compared to that of the normal wiggler. The intensity of radiation field due to the linearly polarized wiggler for the wavelength was also calculated by the developed code.

Keywords: Radiation intensity, Linearly polarized wiggler, Power