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Shiwaku, Hideaki; Mitsui, Takaya; Tozawa, Kazukiyo*
JAEA-Research 2009-009, 60 Pages, 2009/07
The liquid nitrogen circulation cooling device for a double crystal monochromator was introduced, and the multi-crystal switching system was developed on the JAEA dedicated beamline "BL11XU" at SPring-8. The multi-crystal switching system has features to be able to exchange crystals in cryogenic temperature and in a vacuum at any time. By this system, it is available to use high flux X-rays energy range of 6 to 70 keV.
Shobu, Takahisa; Tozawa, Kazukiyo*; Shiwaku, Hideaki; Konishi, Hiroyuki; Inami, Toshiya; Harami, Taikan; Mizuki, Junichiro
AIP Conference Proceedings 879, p.902 - 906, 2007/01
BL22XU with undulator is consisted of one optical hutch and three experimental hutches and about 120m in length. The aim of this beamline is to perform diffraction and absorption experiment with anomalous dispersion, the high pressure experiments at high or low temperature with multi-anvil type and diamond-anvil type high pressure system and stress measurements. The energy region from 3 to 70keV and high flux of X-rays were required to satisfy these experimental conditions. Then we installed two kinds of monochromator by employing Si (111) crystals. One is SPring-8 "standard" double crystal monochromators to make low-energy X-rays from 3 to 37keV (L-mono), the other is double crystal monochromators, mechanically separated, but combined with calculation to make high-energy X-rays from 36 to 72keV (H-mono). These monochromators were arranged in the tandem for optics. L-mono can be used by lowering the first crystal of the H-mono, on the other hand the H-mono can be used by lifting the whole of L-mono. The liquid nitrogen is used for cooling the crystals, and as a result the high quality monochromatized X-rays is obtained. At the position of 115m from undulator, the beam size is 2.5 mm (vertical) 3.5 mm (horizontal) (FWHM) and the flux is estimated to be 3
10
photon/s. But the stability of X-rays is rather poor because of the vibration caused by nitrogen liquid cooling system. The vertical position of X-rays changes by about 0.2 mm in a few minutes of periods, and the intensity of X-rays varies at about 10%. The stable X-rays within a limitation of accuracy can be obtained by using Monochromator stabilization, so called MOSTAB, which is a feedback control system.
Kiriyama, Koji*; Shiwaku, Hideaki; Mochizuki, Tetsuro*; Shobu, Takahisa*; Tozawa, Kazukiyo*
JAERI-Tech 2005-003, 36 Pages, 2005/03
Multi-stabilizing methods for vibrations on the cryogenically cooled monochromator have been tried on BL11XU at SPring-8. Observed vibrations on crystals were mainly 1-10 Hz, 30 Hz, and 50 Hz. The results suggested that sources of the vibrations were liquid nitrogen flow and propagation from vibrations of vacuum pumps equipped with beam line. We took countermeasures of the vibrations to liquid nitrogen tubes, and set parameters (temperature, pressure and flow-late) of the cryogenic cooling system for 1-10 Hz vibration. Vibration absorber was set not to propagate the vibrations from the vacuum pumps and their fans for 30 and 50 Hz vibrations. These methods successfully removed the mechanical vibrations. Then, intensity vibration of X-ray was decreased from 4.47 % to 0.85 %, in the end. The stabilizing methods on BL11XU are expected to apply to the similar system at the other beam-lines.
Tozawa, Kazukiyo*; Kiriyama, Koji*; Mitsui, Takaya; Shiwaku, Hideaki; Harami, Taikan
JAERI-Tech 2004-041, 27 Pages, 2004/03
Liquid-N-cooled Si crystals replaced water-cooled diamond crystals for the double-crystal monochromator on BL11XU at SPring-8. To use the whole energy from 6 keV to 70 keV, we developed the system of dual symmetric Si geometry, Si(111)/Si(311), which can be switched by a horizontal translation (X) stage perpendicular to the beam axis. The off-line experiment was performed to estimate the degree of the crystal strain, which may arise from the way of assembling in the crystal holder. With MoK
, rocking curves from the crystals were measured for the second crystal of the double-crystal diffractometer of parallel setting. Each of the observed full-width at half maximum (FWHM) was almost constant and identical to the calculated value wherever X-rays hit on the crystal surface. By the use of synchrotron radiation from the undulator the crystals were tested and then the characterization was performed. The observed intensities and rocking curves resulted in that each crystal was good for BL11XU and that the performance of X-ray reflection was improved.
Shiwaku, Hideaki; Mitsui, Takaya; Tozawa, Kazukiyo*; Kiriyama, Koji*; Harami, Taikan; Mochizuki, Tetsuro*
AIP Conference Proceedings 705, p.659 - 662, 2004/00
We developed a multi-crystal switching system on a cryogenically cooled monochromator of JAERI materials science beamline, BL11XU. In order to study our science, it is necessary for ensuring at least the energy range of 6 - 70keV to employ Si(111) and Si(311) crystals. The principle of the crystal switching is that, two pair of crystals is arranged side by side, and they are translated in horizontal direction for exchanging. Indium sheets were inserted between both sides of crystals in order to improve thermal contact. Some adjustment stages of the monochromator were removed to avoid the crystal vibration and a sheet heater was installed on an X-axis stage to prevent over-cooling of X-axis stages. The monochromator is under commissioning at present. In comparison with a previous indirect water cooling diamond (111) crystal monochromator, this monochromator provides high flux intensity from 4 times to 7 times. It takes only 5 minutes to exchange and adjust crystals geometry. This mechanism will be easily applied to other crystals, for example asymmetrical-cut crystals.
Tozawa, Kazukiyo*; Kiriyama, Koji*; Mitsui, Takaya; Shiwaku, Hideaki; Harami, Taikan
AIP Conference Proceedings 705, p.671 - 674, 2004/00
Liquid-N-cooled Si crystals replaced water-cooled diamond crystals for the double-crystal monochromator on BL11XU at SPring-8. To use the whole energy from 6keV to 70keV, we adopted the system of alternative dual symmetric Si geometry, Si(111)/Si(311), which can be switched by a horizontal translation (X) stage perpendicular to the beam axis. Before the experiment on BL11XU, the off-line evaluation was performed to estimate the degree of the crystal strain, which may arise from the way of assembling. With MoK
, rocking curves from the crystals were measured for the second crystal of the double-crystal diffractometer of parallel setting. Each of the observed FWHM was almost constant and identical to the calculated value wherever X-rays hit on the crystal surface. By the use of synchrotron radiation from the undulator the crystals were tested and then the characterization was performed. The observed intensities and rocking curves resulted in that each crystal was good for BL11XU and that the performance of X-ray reflection was improved.
Kiriyama, Koji*; Shiwaku, Hideaki; Tozawa, Kazukiyo*
JAERI-Tech 2003-061, 21 Pages, 2003/07
Cryogenically cooled monochromator equipped with circulated-liquid-nitrogen cooling system has been developed on JAERI beam-line, BL11XU, at SPring-8. This cooling system has improved the performance of X-ray reflection. The system has difficulty for the operation because of a lack of the manual. So, it is required to establish a systematic guide of the system. Here we report a manual with fruitful know-how to operate the cryogenic cooling system on BL11XU safely and easily. The new manual is wholly tabulated and shows comments, instructions, and valve conditions in all one-step. The operator, by using this manual, can manipulate the system with no misoperation.
Kiriyama, Koji; Shiwaku, Hideaki; Mochizuki, Tetsuro*; Shobu, Takahisa; Tozawa, Kazukiyo*
no journal, ,
Oscillating inhibition methods for mechanical vibrations on the cryogenically-cooled Si monochromator have been developed on BL11XU at SPring-8. The intensity fluctuation of the X-rays of the monochromator was observed. So, we need to identify the vibration sources and take countermeasures against the vibrations to keep quality of X-rays. In this study, the intensity fluctuation of the X-rays, vibrations larger than 1 Hz on the X-rays and the crystals was measured thoroughly. Without the oscillating inhibition methods, observed intensity fluctuation of X-rays was irregular in several minutes and uneven every second. Measured vibration frequencies were mainly 110 Hz,
20 Hz,
55 Hz on X-rays, and were mainly 1
10 Hz,
30 Hz, and
50 Hz on crystals. The countermeasures were found to be dramatically effective to restrain on the vibrations. As a result, the width of the intensity fluctuation with time decreased from 2.86 percent to 1.46 percent (std. deviation: 0.008302 to 0.004479) that means improving the stability of X-rays from monochromator. The oscillating inhibition methods in the present study on BL11XU at SPring-8 can be applied to the similar monochromator at the other beamlines.