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Vibrational stability of a cryocooled horizontal double-crystal monochromator

Kristiansen, Paw; Johansson, Ulf LU ; Ursby, Thomas LU and Jensen, Brian Norsk LU (2016) In Journal of Synchrotron Radiation 23(Pt 5). p.81-1076
Abstract

The vibrational stability of a horizontally deflecting double-crystal monochromator (HDCM) is investigated. Inherently a HDCM will preserve the vertical beam stability better than a `normal' vertical double-crystal monochromator as the vibrations of a HDCM will almost exclusively affect the horizontal stability. Here both the relative pitch vibration between the first and second crystal and the absolute pitch vibration of the second crystal are measured. All reported measurements are obtained under active cooling by means of flowing liquid nitrogen (LN2). It is found that it is favorable to circulate the LN2 at high pressures and low flow rates (up to 5.9 bar and down to 3 l min(-1) is tested) to attain low vibrations. An absolute pitch... (More)

The vibrational stability of a horizontally deflecting double-crystal monochromator (HDCM) is investigated. Inherently a HDCM will preserve the vertical beam stability better than a `normal' vertical double-crystal monochromator as the vibrations of a HDCM will almost exclusively affect the horizontal stability. Here both the relative pitch vibration between the first and second crystal and the absolute pitch vibration of the second crystal are measured. All reported measurements are obtained under active cooling by means of flowing liquid nitrogen (LN2). It is found that it is favorable to circulate the LN2 at high pressures and low flow rates (up to 5.9 bar and down to 3 l min(-1) is tested) to attain low vibrations. An absolute pitch stability of the second crystal of 18 nrad RMS, 2-2500 Hz, and a relative pitch stability between the two crystals of 25 nrad RMS, 1-2500 Hz, is obtained under cryocooling conditions that allow for 1516 W to be adsorbed by the LN2 before it vaporizes.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Synchrotron radiation, X-ray optics
in
Journal of Synchrotron Radiation
volume
23
issue
Pt 5
pages
6 pages
publisher
Wiley-Blackwell
ISSN
1600-5775
DOI
10.1107/S1600577516009243
language
English
LU publication?
yes
id
12c620c1-1b81-4a58-9ad7-05df768ce5fc
date added to LUP
2016-09-07 10:21:36
date last changed
2016-10-02 13:15:48
@misc{12c620c1-1b81-4a58-9ad7-05df768ce5fc,
  abstract     = {<p>The vibrational stability of a horizontally deflecting double-crystal monochromator (HDCM) is investigated. Inherently a HDCM will preserve the vertical beam stability better than a `normal' vertical double-crystal monochromator as the vibrations of a HDCM will almost exclusively affect the horizontal stability. Here both the relative pitch vibration between the first and second crystal and the absolute pitch vibration of the second crystal are measured. All reported measurements are obtained under active cooling by means of flowing liquid nitrogen (LN2). It is found that it is favorable to circulate the LN2 at high pressures and low flow rates (up to 5.9 bar and down to 3 l min(-1) is tested) to attain low vibrations. An absolute pitch stability of the second crystal of 18 nrad RMS, 2-2500 Hz, and a relative pitch stability between the two crystals of 25 nrad RMS, 1-2500 Hz, is obtained under cryocooling conditions that allow for 1516 W to be adsorbed by the LN2 before it vaporizes.</p>},
  author       = {Kristiansen, Paw and Johansson, Ulf and Ursby, Thomas and Jensen, Brian Norsk},
  issn         = {1600-5775},
  keyword      = {Synchrotron radiation,X-ray optics},
  language     = {eng},
  month        = {09},
  number       = {Pt 5},
  pages        = {81--1076},
  publisher    = {ARRAY(0x88c5880)},
  series       = {Journal of Synchrotron Radiation},
  title        = {Vibrational stability of a cryocooled horizontal double-crystal monochromator},
  url          = {http://dx.doi.org/10.1107/S1600577516009243},
  volume       = {23},
  year         = {2016},
}