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Precision control of gamma-ray polarization using a crossed helical undulator free-electron laser
发布时间:2020-02-14点击次数:
影响因子: 0.0
DOI码: 10.1038/s41566-019-0467-6
发表刊物: Nature Photonics
摘要: 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 polariza- tion 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, PLin = 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 charac- terized and shows PLin = 0.97. This demonstrated polarization control technique is well suited for high-flux gamma-ray produc- tion with any level of FEL power.
卷号: 13
页面范围: 629–635
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发表时间: 2019-09-01
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