Precision control of gamma-ray polarization using a crossed helical undulator free-electron laser

Journal Article (Journal Article)

Polarized gamma-ray beams are a precise and selective probe for studying fundamental questions about nuclear structure and hadron properties. Improvements to this probe require new experimental approaches that can produce high-flux gamma-ray beams with easily switchable pure polarization states. Here, we report an optics-free method to precisely control the polarization of a Compton gamma-ray beam. Using a free-electron laser (FEL) oscillator with two helical undulator magnets of opposite helicities, we have produced a linearly polarized FEL beam with a variable polarization direction and an unprecedented degree of linear polarization, P = 0.997. With this FEL as a photon drive, we are able to generate Compton gamma-ray beams having either left/right-circular polarization or rotatable linear polarization. The linearly polarized gamma-ray beam has been characterized and shows P = 0.97. This demonstrated polarization control technique is well suited for high-flux gamma-ray production with any level of FEL power. Lin Lin

Full Text

Duke Authors

Cited Authors

  • Yan, J; Mueller, JM; Ahmed, MW; Hao, H; Huang, S; Li, J; Litvinenko, VN; Liu, P; Mikhailov, SF; Popov, VG; Sikora, MH; Vinokurov, NA; Wu, YK

Published Date

  • September 1, 2019

Published In

Volume / Issue

  • 13 / 9

Start / End Page

  • 629 - 635

Electronic International Standard Serial Number (EISSN)

  • 1749-4893

International Standard Serial Number (ISSN)

  • 1749-4885

Digital Object Identifier (DOI)

  • 10.1038/s41566-019-0467-6

Citation Source

  • Scopus