TY - JOUR
T1 - Improvement in stability of SPring-8 X-ray monochromators with cryogenic-cooled silicon crystals
AU - Yamazaki, Hiroshi
AU - Ohashi, Haruhiko
AU - Senba, Yasunori
AU - Takeuchi, Tomoyuki
AU - Shimizu, Yasuhiro
AU - Tanaka, Masayuki
AU - Matsuzaki, Yasuhisa
AU - Kishimoto, Hikaru
AU - Miura, Takanori
AU - Terada, Yasuko
AU - Suzuki, Motohiro
AU - Tajiri, Hiroo
AU - Goto, Shunji
AU - Yamamoto, Masaki
AU - Takata, Masaki
AU - Ishikawa, Tetsuya
PY - 2013/1/1
Y1 - 2013/1/1
N2 - SPring-8 standard double-crystal monochromators cooled with liquid nitrogen are being improved for providing a stable supply of intense nanometer-focused X-ray beams. The instability originates from the vibration and thermal deformations of the various stages of the monochromators: the former is caused by turbulent flow of the liquid nitrogen, and the latter is mainly due to unwanted cooling from the liquid nitrogen. A low-vibration flexible tube was devised to stabilize the coolant flow by covering the corrugations of the flexible tube with an alumina fiber textile. To achieve thermal insulation, we inserted a machinable ceramic block and a copper plate between the cooled crystal holder and the stages; the temperature of the copper plate was controlled to within ±0.01 °C using a sheet heater and a proportional-integral-derivative current controller. As a result, the vibration was reduced from 1 to 0.15 in terms of the misalignment angle between the two crystals, and a vertical focus size of 230 nm was achieved by demagnification projection of the real light source onto the focal plane. The angular instability due to the thermal deformation was suppressed to a rate of less than 0.2/h. Furthermore, we discuss ongoing improvements for further stabilization.
AB - SPring-8 standard double-crystal monochromators cooled with liquid nitrogen are being improved for providing a stable supply of intense nanometer-focused X-ray beams. The instability originates from the vibration and thermal deformations of the various stages of the monochromators: the former is caused by turbulent flow of the liquid nitrogen, and the latter is mainly due to unwanted cooling from the liquid nitrogen. A low-vibration flexible tube was devised to stabilize the coolant flow by covering the corrugations of the flexible tube with an alumina fiber textile. To achieve thermal insulation, we inserted a machinable ceramic block and a copper plate between the cooled crystal holder and the stages; the temperature of the copper plate was controlled to within ±0.01 °C using a sheet heater and a proportional-integral-derivative current controller. As a result, the vibration was reduced from 1 to 0.15 in terms of the misalignment angle between the two crystals, and a vertical focus size of 230 nm was achieved by demagnification projection of the real light source onto the focal plane. The angular instability due to the thermal deformation was suppressed to a rate of less than 0.2/h. Furthermore, we discuss ongoing improvements for further stabilization.
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U2 - 10.1088/1742-6596/425/5/052001
DO - 10.1088/1742-6596/425/5/052001
M3 - Conference article
AN - SCOPUS:84876271220
VL - 425
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
SN - 1742-6588
IS - PART 5
M1 - 052001
T2 - 11th International Conference on Synchrotron Radiation Instrumentation, SRI 2012
Y2 - 9 July 2012 through 13 July 2012
ER -