IPAC2012 - List of Keywords (superconducting-RF)

Paper	Title	Other Keywords	Page
MOYAP01	Accelerator Driven Systems	neutron, linac, proton, target	6
	D. Vandeplassche, L. Medeiros Romão SCK•CEN, Mol, Belgium
	Accelerator Driven Systems are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations (transmuters). The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid PbBi (LBE) cooled fast reactor (80 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a CW superconducting linac which is laid out for the highest achievable reliability. The combination of a redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 500 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are entirely focused on the reliability aspects.
	Slides MOYAP01 [6.343 MB]

WEXA01	The High Intensity Horizon at Fermilab	proton, collider, kaon, linac	2065
	R.S. Tschirhart Fermilab, Batavia, USA
	Fermilab’s high intensity horizon is “Project-X” which is a US led initiative with strong international participation that aims to realize a next generation proton source that will dramatically extend the reach of Intensity Frontier research. The Project-X research program includes world leading sensitivity in long-baseline and short-baseline neutrino experiments, a rich program of ultra-rare muon and kaon decays, opportunities for next-generation electric dipole moment experiments and other nuclear/particle physics probes, and a platform to investigate technologies for next generation energy applications. A wide range of R&D activities has been started to support mission critical accelerator subsystems, such as high-gradient superconducting RF accelerating structures, efficient RF power systems, cryo-modules and cryogenic refrigeration plants, advanced beam diagnostics and instrumentation, high-power targetry, as well as the related infrastructure and civil construction preparing for a construction start as early as 2017. The status and prospects of developing the accelerator design, research program, and associated collaborations will be presented. * The Project X program spans several Sub Classifications: A08, A14 A17, A21, A28.
	Slides WEXA01 [9.216 MB]

WEPPC066	Niobium Reaction Kinetics: An Investigation into the Reactions Between Buffered Chemical Polish and Niobium and the Impact on SRF Cavity Etching	niobium, cavity, SRF	2360
	I.M. Malloch, L.J. Dubbs, K. Elliott, R. Oweiss, L. Popielarski FRIB, East Lansing, Michigan, USA
	Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University. In the SRF community, there is no definitive agreement on the precise reaction mechanism in the etching of niobium cavities by buffered chemical polish (BCP) mixtures. As a consequence, it is difficult to predict the heat produced during cavity etching. To gain a better understanding of the reaction kinetics of niobium and BCP, calorimetry experiments were performed to establish an experimental heat of reaction, and research was performed to determine a reasonable reaction scheme to allow for calculation of the theoretical heat of reaction. The results of the calorimetry experiments were in excellent agreement with one another and with the theoretical value. These results will allow for more accurate estimation of etch removal amounts on cavities without the need to perform time-intensive etch rate tests. Applying the experimental data to pre and post cavity etch ultrasonic thickness measurements has shown a significant improvement in the predictability of etch removal amounts in Facility for Rare Isotope Beams (FRIB) half-wave and quarter-wave resonators, and will allow for more reliable heat removal and prevention of Q-disease during other cavity etching procedures.

WEPPC071	Quench Studies of a Superconducting RF Cavity	cavity, superconductivity, resonance, superconducting-cavity	2375
	D. Gonnella, M. Liepe, S. Posen CLASSE, Ithaca, New York, USA
	In tests of superconducting RF cavities, it is important to understand the cause of high field quenches. Quenches at high field above 25 MV/m are a limiting factor in the performance of high accelerating field cavities but their causes are currently not well understood. An ILC shaped single cell cavity with quench field near 40 MV/m was tested with temperature mapping to determine the cause of its hard quench. Prior to quench, heating on the order of 25 mK was concentrated in two hot spots. After a quench, these two hot spots remain and a new one appears with much higher heating (about 40 mK). The quench location was found by the temperature mapping system to be centered at the new hot spot, not at the two hot spot locations before that dominated quench. By studying the quench location and heating on the surface of the cavity, some hints were gained as to the cause of this quench.

WEPPC083	Tunable 28 MHz Superconducting Cavity for RHIC	cavity, niobium, superconducting-cavity, site	2405
	C.H. Boulware, T.L. Grimm Niowave, Inc., Lansing, Michigan, USA S.A. Belomestnykh, I. Ben-Zvi BNL, Upton, Long Island, New York, USA
	Funding: This research has been supported by a Department of Energy Small Business Innovative Research Phase II grant through the Nuclear Physics program office, contract #DE-SC0001215. Replacement of the normal conducting 28 MHz accelerating cavities in the RHIC ring with superconducting structures offers a number of advantages for the machine operation, including reduction of the number of cavities required and improved HOM performance. A prototype folded quarter wave structure is under construction at Niowave, Inc. to meet this need. This novel cavity geometry achieves the very low resonant frequency required with a relatively compact structure, and can provide the large tuning range required (~1% of the cavity frequency). Progress of the cavity fabrication will be presented along with room temperature RF measurements.

Paper

Title

Other Keywords

Page

MOYAP01

Accelerator Driven Systems

neutron, linac, proton, target

6

D. Vandeplassche, L. Medeiros Romão
SCK•CEN, Mol, Belgium

Accelerator Driven Systems are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations (transmuters). The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid PbBi (LBE) cooled fast reactor (80 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a CW superconducting linac which is laid out for the highest achievable reliability. The combination of a redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 500 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are entirely focused on the reliability aspects.

Slides MOYAP01 [6.343 MB]

WEXA01

The High Intensity Horizon at Fermilab

proton, collider, kaon, linac

2065

R.S. Tschirhart
Fermilab, Batavia, USA

Fermilab’s high intensity horizon is “Project-X” which is a US led initiative with strong international participation that aims to realize a next generation proton source that will dramatically extend the reach of Intensity Frontier research. The Project-X research program includes world leading sensitivity in long-baseline and short-baseline neutrino experiments, a rich program of ultra-rare muon and kaon decays, opportunities for next-generation electric dipole moment experiments and other nuclear/particle physics probes, and a platform to investigate technologies for next generation energy applications. A wide range of R&D activities has been started to support mission critical accelerator subsystems, such as high-gradient superconducting RF accelerating structures, efficient RF power systems, cryo-modules and cryogenic refrigeration plants, advanced beam diagnostics and instrumentation, high-power targetry, as well as the related infrastructure and civil construction preparing for a construction start as early as 2017. The status and prospects of developing the accelerator design, research program, and associated collaborations will be presented.
* The Project X program spans several Sub Classifications: A08, A14 A17, A21, A28.

Slides WEXA01 [9.216 MB]

WEPPC066

Niobium Reaction Kinetics: An Investigation into the Reactions Between Buffered Chemical Polish and Niobium and the Impact on SRF Cavity Etching

niobium, cavity, SRF

2360

I.M. Malloch, L.J. Dubbs, K. Elliott, R. Oweiss, L. Popielarski
FRIB, East Lansing, Michigan, USA

Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University.
In the SRF community, there is no definitive agreement on the precise reaction mechanism in the etching of niobium cavities by buffered chemical polish (BCP) mixtures. As a consequence, it is difficult to predict the heat produced during cavity etching. To gain a better understanding of the reaction kinetics of niobium and BCP, calorimetry experiments were performed to establish an experimental heat of reaction, and research was performed to determine a reasonable reaction scheme to allow for calculation of the theoretical heat of reaction. The results of the calorimetry experiments were in excellent agreement with one another and with the theoretical value. These results will allow for more accurate estimation of etch removal amounts on cavities without the need to perform time-intensive etch rate tests. Applying the experimental data to pre and post cavity etch ultrasonic thickness measurements has shown a significant improvement in the predictability of etch removal amounts in Facility for Rare Isotope Beams (FRIB) half-wave and quarter-wave resonators, and will allow for more reliable heat removal and prevention of Q-disease during other cavity etching procedures.

WEPPC071

Quench Studies of a Superconducting RF Cavity

cavity, superconductivity, resonance, superconducting-cavity

2375

D. Gonnella, M. Liepe, S. Posen
CLASSE, Ithaca, New York, USA

In tests of superconducting RF cavities, it is important to understand the cause of high field quenches. Quenches at high field above 25 MV/m are a limiting factor in the performance of high accelerating field cavities but their causes are currently not well understood. An ILC shaped single cell cavity with quench field near 40 MV/m was tested with temperature mapping to determine the cause of its hard quench. Prior to quench, heating on the order of 25 mK was concentrated in two hot spots. After a quench, these two hot spots remain and a new one appears with much higher heating (about 40 mK). The quench location was found by the temperature mapping system to be centered at the new hot spot, not at the two hot spot locations before that dominated quench. By studying the quench location and heating on the surface of the cavity, some hints were gained as to the cause of this quench.

WEPPC083

Tunable 28 MHz Superconducting Cavity for RHIC

cavity, niobium, superconducting-cavity, site

2405

C.H. Boulware, T.L. Grimm
Niowave, Inc., Lansing, Michigan, USA
S.A. Belomestnykh, I. Ben-Zvi
BNL, Upton, Long Island, New York, USA

Funding: This research has been supported by a Department of Energy Small Business Innovative Research Phase II grant through the Nuclear Physics program office, contract #DE-SC0001215.
Replacement of the normal conducting 28 MHz accelerating cavities in the RHIC ring with superconducting structures offers a number of advantages for the machine operation, including reduction of the number of cavities required and improved HOM performance. A prototype folded quarter wave structure is under construction at Niowave, Inc. to meet this need. This novel cavity geometry achieves the very low resonant frequency required with a relatively compact structure, and can provide the large tuning range required (~1% of the cavity frequency). Progress of the cavity fabrication will be presented along with room temperature RF measurements.