Open AccessPhotoelectron shield for the first mirror of a soft X‐ray beamline
Author(s) -
Wakabayashi Daisuke,
Tanaka Hirokazu,
Toyoshima Akio,
Yamashita Shohei,
Takeichi Yasuo
Publication year - 2021
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577520013648
Subject(s) - undulator , photoelectric effect , beamline , materials science , shield , vacuum chamber , optics , x ray , physics , atomic physics , beam (structure) , composite material , petrology , geology
At a soft X‐ray beamline with an undulator source, significant heat generation at the first‐mirror chamber and light emission at the viewport were found, which can be explained by photoelectrons from the mirror. The chamber temperature increases up to approximately 50°C over a period of several hours. A photoelectron shield consisting of thin copper plates not only prevents the heat generation and light emission but also improves the pressure of the vacuum chamber, if a voltage of a few tens of V is applied to the shield. The total electron yield of the shield reached as much as 58 mA under high heat‐load conditions, indicating the emission of numerous photoelectrons from the first mirror. Heat‐balance analyses suggest that approximately 30% or more of the heat load on the first mirror is transferred to the surroundings.