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Title: The Gas Attenuator of FLASH at DESY

Abstract

FLASH (Free electron LASer at Hamburg) as a part of the Deutsches Elektronen Synchroton DESY is the first Free Electron Laser (FEL) user facility for VUV and soft X-ray coherent light experiments. The SASE (Self Amplification by Stimulated Emission) process generates ultra short coherent radiation pulses on the femtosecond time scale with peak powers in the GW range. Several experiments need reliable means to reduce the FEL intensity over many orders of magnitude without changing the photon beam characteristics. Since a reduction of the FEL intensity by variation of machine parameters is not appropriate, a windowless gas-filled cell in combination with differential pumping units is used for attenuating the FEL radiation. This attenuator is placed in the beamline in outside the experimental hall. The total length of the gas cell is 15 m and the maximum gas pressure, which can be handled by the differential pumping units, is about 0.1 mbar. The attenuation range of Nitrogen covers at least 5 orders of magnitude in the spectral range of 19 to 120 nm due to its large absorption cross section. Between 19 and 9 nm and for shorter wavelengths Xenon and Krypton can be used, respectively.

Authors:
;  [1]
  1. Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22603 Hamburg (Germany)
Publication Date:
OSTI Identifier:
21043428
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 879; Journal Issue: 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2436055; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ABSORPTION; AMPLIFICATION; ATTENUATION; BEAM PRODUCTION; COHERENT RADIATION; DESY; FAR ULTRAVIOLET RADIATION; FREE ELECTRON LASERS; KRYPTON; LASER RADIATION; PHOTON BEAMS; PULSES; SOFT X RADIATION; STIMULATED EMISSION; VARIATIONS; WAVELENGTHS; XENON

Citation Formats

Hahn, Ulrich, and Tiedtke, Kai. The Gas Attenuator of FLASH at DESY. United States: N. p., 2007. Web. doi:10.1063/1.2436055.
Hahn, Ulrich, & Tiedtke, Kai. The Gas Attenuator of FLASH at DESY. United States. doi:10.1063/1.2436055.
Hahn, Ulrich, and Tiedtke, Kai. Fri . "The Gas Attenuator of FLASH at DESY". United States. doi:10.1063/1.2436055.
@article{osti_21043428,
title = {The Gas Attenuator of FLASH at DESY},
author = {Hahn, Ulrich and Tiedtke, Kai},
abstractNote = {FLASH (Free electron LASer at Hamburg) as a part of the Deutsches Elektronen Synchroton DESY is the first Free Electron Laser (FEL) user facility for VUV and soft X-ray coherent light experiments. The SASE (Self Amplification by Stimulated Emission) process generates ultra short coherent radiation pulses on the femtosecond time scale with peak powers in the GW range. Several experiments need reliable means to reduce the FEL intensity over many orders of magnitude without changing the photon beam characteristics. Since a reduction of the FEL intensity by variation of machine parameters is not appropriate, a windowless gas-filled cell in combination with differential pumping units is used for attenuating the FEL radiation. This attenuator is placed in the beamline in outside the experimental hall. The total length of the gas cell is 15 m and the maximum gas pressure, which can be handled by the differential pumping units, is about 0.1 mbar. The attenuation range of Nitrogen covers at least 5 orders of magnitude in the spectral range of 19 to 120 nm due to its large absorption cross section. Between 19 and 9 nm and for shorter wavelengths Xenon and Krypton can be used, respectively.},
doi = {10.1063/1.2436055},
journal = {AIP Conference Proceedings},
number = 1,
volume = 879,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}