SRF2015 - List of Keywords (detector)

Paper	Title	Other Keywords	Page
MOPB023	Detectors Sensing Second Events Induced by Thermal Quenches of SRF Cavities in He II	SRF, cavity, instrumentation, diagnostics	135
	M. Fouaidy, F. Dubois, D. Longuevergne, O. Pochon, J.-F. Yaniche IPN, Orsay, France
	SRF bulk Nb cavities are often limited by quench due to anomalous losses (heating due normal defects or Field Emission). We continued R&D on Quench Detectors (QD) activity for locating quench in SRF cavities via 2nd sound in superfluid helium. We investigated 2 kinds of QD: Capacitive OST (COST) and Low Response time resistive Thermometers (LRT). A test stand operating in LHe (Temperature: T0) was used for the characterization of the QD by means of precise experimental simulation of SRF cavity quench (pulsed heat flux qP). For improving spatial resolution of QD, smaller COSTs were developed and tested. We investigated the dynamic response of QD as function of different parameters (heater size/geometry, T0, qP) and data are reported. Further, a 2nd Sound Resonator (SSR), with a pair of COSTs at its 2 extremities as 2nd Sound Generator (SSG) and Detector (SSD) respectively and housing also a low heat capacity heater (SSG) and a LRT (SSD) assembly was developed. The first experimental data obtained, with SSR operated in resonating mode or in a shock wave mode are presented. The results concerning locating of quenches in QWR and spoke cavities are discussed.
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MOPB049	High Flux Three Dimensional Heat Transport in Superfluid Helium and Its Application to a Trilateration Algorithm for Quench Localization With OSTs	cavity, experiment, niobium, software	201
	T. Junginger TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada P. Horn TU Dresden, Dresden, Germany T. Koettig, K.C. Liao, A. Macpherson CERN, Geneva, Switzerland B.J. Peters KIT, Karlsruhe, Germany
	Oscillating superleak transducers of second sound can be used to localize quench spots on superconducting cavities by trilateration. However propagation speeds faster than the velocity of second sound are usually observed imped- ing the localization. Dedicated experiments show that the fast propagation cannot be correlated to the dependence of the velocity on the heat flux density, but rather to boiling effects in the vicinity of the hot spot. 17 OSTs were used to detect quenches on a 704MHz one-cell elliptical cavity. Two different algorithms for quench localization have been tested and implemented in a computer program enabling direct crosschecks. The new algorithm gives more consis- tent results for different OST signals analyzed for the same quench spot.
	Poster MOPB049 [0.901 MB]
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MOPB051	Muon Spin Rotation on Treated Nb Samples in Parallel Field Geometry	cavity, SRF, polarization, niobium	210
	S. Gheidi UBC, Vancouver, B.C., Canada T.J. Buck, T. Junginger, R.E. Laxdal, G. Morris TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada M. Dehn TUM/Physik, Garching bei München, Germany R. Kiefl UBC & TRIUMF, Vancouver, British Columbia, Canada
	MuSR is a powerful tool to probe local magnetism and hence can be used to diagnose the entry of magnetic flux in superconductors. First measurements on SRF samples were done with an external DC field applied perpendicular to the sample1 (transverse geometry) with the muons applied to the sample face. Here the results are strongly impacted by demagnetization, pinning strength and edge effects. A new spectrometer has been developed to allow sample testing with a field varying from 0 to 300mT applied along the sample face (parallel geometry) analogous to rf fields in SRF resonators. The geometry is characterized by a small demagnetization factor reducing the impact of pinning and edge effects on field of first flux entry. The beamline installation and first results comparing transverse and parallel results will be presented. 1 Grassellino et al. Muon spin rotation studies of niobium for superconducting rf applications. Phys. Rev. ST Accel. Beams, 16:062002, Jun 2013.
	Poster MOPB051 [0.719 MB]
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TUPB024	Tuning the Linac With Superconducting Resonator Used as a Phase Detector	linac, acceleration, ion, bunching	602
	N.R. Lobanov, P. Linardakis, D. Tsifakis Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia
	The ANU Heavy Ion Facility is comprised of a 15 MV electrostatic accelerator and superconducting linac booster. The beam is double terminal stripped to provide high charge states at the entrance to the linac, which consists of twelve β=0.1 Split Loop Resonators (SLR). Each SLR needs to be individually tuned in phase and amplitude for optimum acceleration efficiency. The amplitude and phase of the superbuncher and time energy lens also have to be correctly set. The linac set up procedure developed at ANU utilises a beam profile monitor in the middle of a 180 degree achromat and a new technique based on a superconducting resonator operating in a beam bunch detection mode. Both techniques are used to derive a full set of phase distributions for quick and efficient setting up of the entire linac. Verification of the superconducting phase detector is accomplished during routine linac operations and is complemented by longitudinal phase space simulations. The new technique allows better resolution for setting the resonator acceleration phase and better sensitivity to accelerating current.
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TUPB079	Second Sound Quench Detection of Dressed TESLA-Shape SRF Cavities	cavity, simulation, SRF, HOM	774
	Y. Tamashevich University of Hamburg, Hamburg, Germany E. Elsen, A. Navitski DESY, Hamburg, Germany
	A compact detector and numerical algorithm for second sound measurements has been developed. The detector allows precise 3D quench localisation within a single unit and can be used even for cavities with mounted helium tank. The compact device is easily mounted and requires minimum space. It can be used as a part of the standard cold test of cavities. The results obtained with the new detector and a 3D algorithm have been cross-checked by optical inspection and resistor-based temperature mapping. The resolution of the detector is seen to be limited by the sampling rate and the lateral extent of the quench induced heated area on the Nb superconductor.
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TUPB087	Development of an X-Ray Fluorescence Probe for Inner Cavity Inspection	cavity, niobium, radiation, background	799
	M. Bertucci, P. Michelato, L. Monaco, M. Moretti, C. Pagani INFN/LASA, Segrate (MI), Italy A. Navitski DESY, Hamburg, Germany
	The development of an x-ray fluorescence probe for detection of foreign material inclusions of the inner surface of 1.3 GHz tesla-type Niobium cavities is here presented. The setup dimensions are minimized so to access the inner cavity volume and focus on the surface of equator. Preliminary tests confirmed the system capability to detect and localize with good precision small metal inclusions of few micrograms. The results obtained from the inspection of some 1.3 GHz XFEL series production cavities are also pointed out.
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TUPB115	Improvements of the Mechanical, Vacuum and Cryogenic Procedures for European XFEL Cryomodule Testing	cryomodule, vacuum, operation, cryogenics	906
	J. Świerbleski, M. Bednarski, B. Dzieza, W. Gaj, L. Grudnik, P. Halczynski, A. Kotarba, A. Krawczyk, K. Myalski, T. Ostrowicz, B. Prochal, J. Rafalski, M. Sienkiewicz, M. Skiba, M. Wartak, M. Wiencek, J. Zbroja, P. Ziolkowski IFJ-PAN, Kraków, Poland
	The European X-ray Free Electron Laser is under construction at DESY, Hamburg. The linear accelerator part of the laser consists of 100 SRF cryomodules. Before installation in the tunnel the cryomodules undergo a series of performance tests at the AMTF Hall. Testing procedures have been implemented based on TTF (Tesla Test Facility) experience. However, the rate of testing and number of test benches is greater than in the TTF infrastructure. To maintain the goal testing rate of one module per week, improvement to the existing procedures were implemented at AMTF. Around 50% of the testing time is taken by connection of the cryomodule to the test bench, performing all necessary checks and cool down. Most of the preparation procedures have been optimized to decrease mounting time. This paper describes improvements made to the mechanical connections, vacuum checks and cryogenics operation.
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FRAA03	High Gradient Performance in Fermilab ILC Cryomodule	cavity, cryomodule, vacuum, operation	1432
	E.R. Harms, C.M. Baffes, K. Carlson, B.E. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, A. Hocker, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, J.N. Makara, D. McDowell, O.A. Nezhevenko, D.J. Nicklaus, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, W.M. Soyars, P. Varghese, A. Warner Fermilab, Batavia, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Fermilab has assembled an ILC like cryomodule using U.S. processed high gradient cavities and achieved an average gradient of 31.5 MV/m for the entire cryomodule. Test results and challenges along the way will be discussed.
	Slides FRAA03 [5.878 MB]
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Paper

Title

Other Keywords

Page

MOPB023

Detectors Sensing Second Events Induced by Thermal Quenches of SRF Cavities in He II

SRF, cavity, instrumentation, diagnostics

135

M. Fouaidy, F. Dubois, D. Longuevergne, O. Pochon, J.-F. Yaniche
IPN, Orsay, France

SRF bulk Nb cavities are often limited by quench due to anomalous losses (heating due normal defects or Field Emission). We continued R&D on Quench Detectors (QD) activity for locating quench in SRF cavities via 2nd sound in superfluid helium. We investigated 2 kinds of QD: Capacitive OST (COST) and Low Response time resistive Thermometers (LRT). A test stand operating in LHe (Temperature: T0) was used for the characterization of the QD by means of precise experimental simulation of SRF cavity quench (pulsed heat flux qP). For improving spatial resolution of QD, smaller COSTs were developed and tested. We investigated the dynamic response of QD as function of different parameters (heater size/geometry, T0, qP) and data are reported. Further, a 2nd Sound Resonator (SSR), with a pair of COSTs at its 2 extremities as 2nd Sound Generator (SSG) and Detector (SSD) respectively and housing also a low heat capacity heater (SSG) and a LRT (SSD) assembly was developed. The first experimental data obtained, with SSR operated in resonating mode or in a shock wave mode are presented. The results concerning locating of quenches in QWR and spoke cavities are discussed.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

MOPB049

High Flux Three Dimensional Heat Transport in Superfluid Helium and Its Application to a Trilateration Algorithm for Quench Localization With OSTs

cavity, experiment, niobium, software

201

T. Junginger
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
P. Horn
TU Dresden, Dresden, Germany
T. Koettig, K.C. Liao, A. Macpherson
CERN, Geneva, Switzerland
B.J. Peters
KIT, Karlsruhe, Germany

Oscillating superleak transducers of second sound can be used to localize quench spots on superconducting cavities by trilateration. However propagation speeds faster than the velocity of second sound are usually observed imped- ing the localization. Dedicated experiments show that the fast propagation cannot be correlated to the dependence of the velocity on the heat flux density, but rather to boiling effects in the vicinity of the hot spot. 17 OSTs were used to detect quenches on a 704MHz one-cell elliptical cavity. Two different algorithms for quench localization have been tested and implemented in a computer program enabling direct crosschecks. The new algorithm gives more consis- tent results for different OST signals analyzed for the same quench spot.

Poster MOPB049 [0.901 MB]

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MOPB051

Muon Spin Rotation on Treated Nb Samples in Parallel Field Geometry

cavity, SRF, polarization, niobium

210

S. Gheidi
UBC, Vancouver, B.C., Canada
T.J. Buck, T. Junginger, R.E. Laxdal, G. Morris
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
M. Dehn
TUM/Physik, Garching bei München, Germany
R. Kiefl
UBC & TRIUMF, Vancouver, British Columbia, Canada

MuSR is a powerful tool to probe local magnetism and hence can be used to diagnose the entry of magnetic flux in superconductors. First measurements on SRF samples were done with an external DC field applied perpendicular to the sample1 (transverse geometry) with the muons applied to the sample face. Here the results are strongly impacted by demagnetization, pinning strength and edge effects. A new spectrometer has been developed to allow sample testing with a field varying from 0 to 300mT applied along the sample face (parallel geometry) analogous to rf fields in SRF resonators. The geometry is characterized by a small demagnetization factor reducing the impact of pinning and edge effects on field of first flux entry. The beamline installation and first results comparing transverse and parallel results will be presented.
1 Grassellino et al. Muon spin rotation studies of niobium for superconducting rf applications.
Phys. Rev. ST Accel. Beams, 16:062002, Jun 2013.

Poster MOPB051 [0.719 MB]

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TUPB024

Tuning the Linac With Superconducting Resonator Used as a Phase Detector

linac, acceleration, ion, bunching

602

N.R. Lobanov, P. Linardakis, D. Tsifakis
Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia

The ANU Heavy Ion Facility is comprised of a 15 MV electrostatic accelerator and superconducting linac booster. The beam is double terminal stripped to provide high charge states at the entrance to the linac, which consists of twelve β=0.1 Split Loop Resonators (SLR). Each SLR needs to be individually tuned in phase and amplitude for optimum acceleration efficiency. The amplitude and phase of the superbuncher and time energy lens also have to be correctly set. The linac set up procedure developed at ANU utilises a beam profile monitor in the middle of a 180 degree achromat and a new technique based on a superconducting resonator operating in a beam bunch detection mode. Both techniques are used to derive a full set of phase distributions for quick and efficient setting up of the entire linac. Verification of the superconducting phase detector is accomplished during routine linac operations and is complemented by longitudinal phase space simulations. The new technique allows better resolution for setting the resonator acceleration phase and better sensitivity to accelerating current.

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB079

Second Sound Quench Detection of Dressed TESLA-Shape SRF Cavities

cavity, simulation, SRF, HOM

774

Y. Tamashevich
University of Hamburg, Hamburg, Germany
E. Elsen, A. Navitski
DESY, Hamburg, Germany

A compact detector and numerical algorithm for second sound measurements has been developed. The detector allows precise 3D quench localisation within a single unit and can be used even for cavities with mounted helium tank. The compact device is easily mounted and requires minimum space. It can be used as a part of the standard cold test of cavities. The results obtained with the new detector and a 3D algorithm have been cross-checked by optical inspection and resistor-based temperature mapping. The resolution of the detector is seen to be limited by the sampling rate and the lateral extent of the quench induced heated area on the Nb superconductor.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB087

Development of an X-Ray Fluorescence Probe for Inner Cavity Inspection

cavity, niobium, radiation, background

799

M. Bertucci, P. Michelato, L. Monaco, M. Moretti, C. Pagani
INFN/LASA, Segrate (MI), Italy
A. Navitski
DESY, Hamburg, Germany

The development of an x-ray fluorescence probe for detection of foreign material inclusions of the inner surface of 1.3 GHz tesla-type Niobium cavities is here presented. The setup dimensions are minimized so to access the inner cavity volume and focus on the surface of equator. Preliminary tests confirmed the system capability to detect and localize with good precision small metal inclusions of few micrograms. The results obtained from the inspection of some 1.3 GHz XFEL series production cavities are also pointed out.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB115

Improvements of the Mechanical, Vacuum and Cryogenic Procedures for European XFEL Cryomodule Testing

cryomodule, vacuum, operation, cryogenics

906

J. Świerbleski, M. Bednarski, B. Dzieza, W. Gaj, L. Grudnik, P. Halczynski, A. Kotarba, A. Krawczyk, K. Myalski, T. Ostrowicz, B. Prochal, J. Rafalski, M. Sienkiewicz, M. Skiba, M. Wartak, M. Wiencek, J. Zbroja, P. Ziolkowski
IFJ-PAN, Kraków, Poland

The European X-ray Free Electron Laser is under construction at DESY, Hamburg. The linear accelerator part of the laser consists of 100 SRF cryomodules. Before installation in the tunnel the cryomodules undergo a series of performance tests at the AMTF Hall. Testing procedures have been implemented based on TTF (Tesla Test Facility) experience. However, the rate of testing and number of test benches is greater than in the TTF infrastructure. To maintain the goal testing rate of one module per week, improvement to the existing procedures were implemented at AMTF. Around 50% of the testing time is taken by connection of the cryomodule to the test bench, performing all necessary checks and cool down. Most of the preparation procedures have been optimized to decrease mounting time. This paper describes improvements made to the mechanical connections, vacuum checks and cryogenics operation.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

FRAA03

High Gradient Performance in Fermilab ILC Cryomodule

cavity, cryomodule, vacuum, operation

1432

E.R. Harms, C.M. Baffes, K. Carlson, B.E. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, A. Hocker, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, J.N. Makara, D. McDowell, O.A. Nezhevenko, D.J. Nicklaus, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, W.M. Soyars, P. Varghese, A. Warner
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Fermilab has assembled an ILC like cryomodule using U.S. processed high gradient cavities and achieved an average gradient of 31.5 MV/m for the entire cryomodule. Test results and challenges along the way will be discussed.

Slides FRAA03 [5.878 MB]

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