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ABSTRACT: The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression.
AIP Conference Proceedings. 03/2008; 985(1):309-315.
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D. Stout,
S. Assadi,
I. Campisi,
F. Casagrande,
M. Crofford,
R. Devan,
X. Geng,
T. Hardek,
S. Henderson, M. Howell,
Y. Kang,
W. Stone,
W. Strong,
D. Williams,
P. Wright
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ABSTRACT: The spallation neutron source (SNS) project was completed with only limited superconducting RF (SRF) facilities installed as part of the project. A concerted effort has been initiated to install the infrastructure and equipment necessary to maintain and repair the superconducting Linac, and to support power upgrade research and development (R&D). Installation of a Class 10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is underway. A horizontal cryostat, which can house a helium vessel/cavity and fundamental power coupler for full power, pulsed testing, is being procured. Equipment for cryomodule assembly and disassembly is being procured. This effort, while derived from the experience of the SRF community, will provide a unique high power test capability as well as long term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF facilities.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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I.E. Campisi,
S. Assadi,
F. Casagrande,
M. Crofford,
G. Dodson,
J. Galambos,
M. Giannella,
S. Henderson, M. Howell,
Y. Kang,
K. Kasemir,
S.H. Kim,
Z. Kursun,
P. Ladd,
H. Ma,
D. Stout,
W. Strong,
Y. Zhang,
M. Champion
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ABSTRACT: The Superconducting Linac at SNS has been operating with beam for almost two years. As the first operational pulsed superconducting linac, many of the aspects of its performance were unknown and unpredictable. A lot of experience has been gathered during the commissioning of its components, during the beam turn on and during operation at increasingly higher beam power. Some cryomodules have been cold for well over two years and have been extensively tested. The operation has been consistently conducted at 4.4 K and 10 and 15 pulses per second, with some cryomodules tested at 30 and 60 Hz and some tests performed at 2 K. Careful balance between safe operational limits and the study of conditions, parameters and components that create physical limits has been achieved.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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D. Hatfield,
F. Casagrande,
I. Campisi,
P. Gurd, M. Howell,
D. Stout,
H. Strong,
D. Arenius,
J. Creel,
K. Dixon,
V. Ganni,
P. Knudsen
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ABSTRACT: The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented. © 2006 American Institute of Physics
AIP Conference Proceedings. 04/2006; 823(1):1436-1443.
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F. Casagrande,
I. Campisi,
P. Gurd,
D. Hatfield, M. Howell,
D. Stout,
H. Strong,
D. Arenius,
J. Creel,
K. Dixon,
V. Ganni,
P. Knudsen
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ABSTRACT: The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 Watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning strategy and status will be presented.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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ABSTRACT: The Spallation Neutron Source (SNS) superconducting linac (SCL) consists of 11 medium beta (0.61) and 12 high beta (0.81) superconducting RF cryomodules, 32 intersegment quadrupole magnet/diagnostics stations, 9 spool beampipes for future upgrade cryomodules, and two differential pumping stations on either end of the SCL. The cryomodules and spool beampipes were designed and manufactured by Jefferson Laboratory, and the quadrupole magnets and beam position monitors were designed and furnished by Los Alamos National Laboratory. Remaining items were designed by Oak Ridge National Laboratory. At present the SCL is being installed and tested. This paper discusses the experience gained during installation and the performance in terms of mechanical and cryogenic systems.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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I.E. Campisi,
S. Assadi,
F. Casagrande,
M. Champion,
P. Chu,
S. Cousineau,
M. Crofford,
C. Deibele,
J.D. Galambos,
P. Gurd, [......],
D. Jeon,
Y.W. Kang,
K. Kasemir,
Z. Kursun,
H. Ma,
M. Piller,
D. Stout,
W. Strong,
A. Vassioutchenko,
Y. Zhang
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ABSTRACT: The Spallation Neutron Source being built at Oak Ridge National Laboratory employs eighty one 805 MHz superconducting cavities operated at 2.1 K to accelerate the H-beam from 187 MeV to about 1 GeV. The superconducting cavities and cryomodules with two different values of beta (. 61 and .81) have been designed and constructed at Jefferson Lab for operation at 2.1 K with unloaded Q’s in excess of 5×10<sup>9</sup>. To gain experience in testing cryomodules in the SNS tunnel before the final commissioning of the 2.1 K Central Helium Liquefier, integration tests are being conducted on the cryomodules at 4.2 K. This is the first time that a superconducting cavity system specifically designed for 2.1 K operation has been extensively tested at 4.2 K without superfluid helium.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
