| Paper |
Title |
Page |
| TUPC061 |
Laser Wire Beam Profile Monitor at Spallation Neutron Source (SNS)
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1197 |
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- Y. Liu, S. Assadi, W. P. Grice, C. D. Long
ORNL, Oak Ridge, Tennessee
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We report the first measurement of a hydrogen ion beam profile in the superconducting linear accelerator (SCL) at the Spallation Neutron Source (SNS) with a laser wire beam profile monitor. The advantage of the laser beam profile monitor includes non-invasive measurement, longitudinal beam scan and multiple station measurement capabilities. A Q-switched Nd:YAG laser at 1.06 μm is used to detach electrons from hydrogen ions. The laser has a repetition rate of 30 Hz and a pulse width of 7 ns. Typical pulse energies are 50 - 200 mJ. The laser is physically located outside the SCL tunnel and the ion beam profiles are measured at 9 different locations covering the entire SCL region (~ 200 m). At SNS the beam structure consists of 50 ps long micropulses separation by ~ 2.5 ns and gated into macropulses of up to 1 ms long. The firing of the laser flashlamps is synchronized to the macropulse timing. The collection magnet bends the photodetached electrons out of the beam and into a Faraday cup. Both horizontal and vertical beam profiles (typical width: 2 - 4 mm) can be measured with a resolution of 4 um. Transverse beam scans can be performed throughout the macropulse.
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| TUPC125 |
Status of the Spallation Neutron Source Superconducting RF Facility
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1362 |
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- F. Casagrande, S. Assadi, M. T. Crofford, W. R. DeVan, X. Geng, T. W. Hardek, S. Henderson, M. P. Howell, Y. W. Kang, J. Mammosser, W. C. Stone, D. Stout, W. H. Strong, D. C. Williams, P. A. Wright
ORNL, Oak Ridge, Tennessee
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The Spallation Neutron Source (SNS) project was completed without on-site superconducting RF (SRF) facilities. Installation of the infrastructure necessary to maintain and repair the superconducting Linac and to support power upgrade research and development (R&D) is well underway. Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is now complete. These systems were recently operated satisfactorily to test a cryomodule that had been removed from the accelerator and repaired in the cleanroom. A horizontal cryostat has been fabricated and will be soon commissioned. Equipment for cryomodule assembly and disassembly has been installed and used for cryomodule disassembly. Cavity processing equipment, specifically an ultra-pure water system, high pressure rinse system, and vertical test area is being designed and installed. This effort is providing both 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 test facility.
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| TUPD037 |
Design and Development of Intercepting Devices at the Spallation Neutron Source
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1508 |
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- R. T. Roseberry, S. Assadi, D. W. Crisp, K. R. Gawne
ORNL, Oak Ridge, Tennessee
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Beam measurements in the LINAC and transport lines of the Spallation Neutron Source at Oak Ridge National Laboratory utilize a variety of intercepting instruments such as in-line emittance systems, wire scanners, scrapers and scintillation view screens. All of these devices require linear actuators with vacuum feedthroughs. The majority of the actuators acquired during the construction phase of the SNS were of commercial origin and have proven unable to meet long-term physics and engineering requirements. The predominant difficulties with these devices were lack of precision, reliability and longevity. Three new families of linear actuators have been developed at the SNS to address these deficiencies. The approach used in their development, has been to utilize a combination of commercially available linear motion components in custom built chassis to address the needs of a given set of applications. This approach has yielded devices that have met or exceeded expectations for accuracy, precision, radiation resistance, longevity and economy. Aspects of the underlying design of these actuators and their implementation will be presented at this conference.
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