SRF2015 - List of Keywords (storage-ring)

Paper	Title	Other Keywords	Page
TUAA03	BESSY VSR: A Novel Application of SRF for Synchrotron Light Sources	cavity, damping, SRF, HOM	462
	A.V. Vélez, H.-W. Glock, P. Goslawski, A. Jankowiak, J. Knobloch, A. Neumann, M. Ries, G. Wüstefeld HZB, Berlin, Germany
	CW SRF Cavities have been used very successfully in the past in synchrotron light sources to provide high power acceleration. Here we present a novel application of higher harmonic systems of two frequencies (1.5 GHz and 1.75 GHz) to generate a beating of accelerating voltage. With such a system it is possible to store "standard" (some 10 ps long) and "short" (ps and sub-ps long) pulses simultaneously in the light source. This opens up brand new possibilities for light source users to perform dynamic and high-resolution experiments at the same facility. The demands on the SRF system and RF control are substantial and a new design, based on waveguide damping, is currently being developed. This system will be used for a major upgrade of the BESSY-II facility to the BESSY Variable Pulse Storage Ring (BESSY-VSR) for a next-generation storage-ring light source. We will discuss the concept, challenges and designs for BESSY-VSR.
	Slides TUAA03 [2.103 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB002	Elimination of High Frequency Noise From the Beam in the Diamond Light Source Storage Ring	operation, synchrotron, controls, power-supply	525
	C. Christou, A. Bogusz, P.J. Marten DLS, Oxfordshire, United Kingdom
	High frequency beam motion has been identified as a source of noise in infrared beamlines in a number of synchrotron light sources. Diamond is a third generation synchrotron light source with storage ring current maintained by two superconducting CESR-B cavities powered by IOT-driven RF amplifiers. In our case, undesirable beam motion in the kilohertz range is predominantly driven by spectral content in the voltage across the IOTs arising from the switched mode nature of the high voltage power supply. Spectral noise on the amplifiers and beam has been identified and characterised and efforts to eliminate this noise are described. Care has been taken to maintain the overall stability of the RF at Diamond and tests have been carried out on an infrared beamline to investigate the degree to which beam noise impacts beamline operation in its different operating configurations.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB006	The CLS SRF Cryogenic System Upgrade	cryomodule, cavity, SRF, cryogenics	539
	C.N. Regier CLS, Saskatoon, Saskatchewan, Canada
	The Canadian Light Source currently makes use of a 500 MHz CESR-B type SRF cavity in its storage ring. While the performance of this cavity has generally been good, the reliability of the cryostat and cryogenic system has suffered a few setbacks over the 10 years of operation. The position of CLS as a user facility requires reliable beam to be consistently delivered. For this reason CLS is undertaking an upgrade project to improve system reliability and reduce downtime due to planned and unplanned maintenance. The upgrade is to include a redundant helium compressor, and new cryogenic infrastructure. In addition, the spare CESR-B cryomodule will be installed and operating in the storage ring. This talk reviews the problems with the current system to date, and discusses the proposals for the upgrade of the system.
	Poster TUPB006 [0.622 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB088	20 kW CW Power Couplers for the APS-U Harmonic Cavity	cavity, Windows, operation, electron	1346
	M.P. Kelly, A. Barcikowski, Z.A. Conway, D. Horan, M. Kedzie, S.H. Kim, P.N. Ostroumov ANL, Argonne, Illinois, USA S.V. Kutsaev RadiaBeam, Santa Monica, California, USA J. Rathke AES, Medford, New York, USA
	Funding: This work supported by the U.S. DOE, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357. This research used resources of ANL’s ATLAS facility, which is a DOE Office of Science User Facility. A pair of 20 kW CW adjustable RF power couplers optimized for 1.4 GHz have been designed and are being built as part of the APS-U bunch lengthening system. The system uses one superconducting RF cavity to be installed into the APS Upgrade electron storage ring and will provide a tremendous practical benefit to the majority of users by increasing the beam lifetime by 2-3 times. The 80 mm diameter, 50 Ω coaxial couplers include 4 cm (~20 dB) of adjustability. This allows optimization of bunch lengthening for a range of storage ring beam currents and fill patterns while, simultaneously, maintaining the required 0.84 MV harmonic cavity voltage. To provide bunch lengthening, the cavity/coupler system must extract RF power (up to 32 kW) from the beam. Each coupler will transmit roughly half of the total extracted power to external water-cooled loads. The design extends upon on a well-tested ANL two RF window concept, using a pair of simple rugged 80 mm diameter alumina disks. A new feature is the ‘hourglass-shaped’ inner conductor chosen to maximize transmission at 1.4 GHz. Results of electromagnetic and thermal simulations, as well as, prototyping and initial RF testing are presented.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUAA03

BESSY VSR: A Novel Application of SRF for Synchrotron Light Sources

cavity, damping, SRF, HOM

462

A.V. Vélez, H.-W. Glock, P. Goslawski, A. Jankowiak, J. Knobloch, A. Neumann, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

CW SRF Cavities have been used very successfully in the past in synchrotron light sources to provide high power acceleration. Here we present a novel application of higher harmonic systems of two frequencies (1.5 GHz and 1.75 GHz) to generate a beating of accelerating voltage. With such a system it is possible to store "standard" (some 10 ps long) and "short" (ps and sub-ps long) pulses simultaneously in the light source. This opens up brand new possibilities for light source users to perform dynamic and high-resolution experiments at the same facility. The demands on the SRF system and RF control are substantial and a new design, based on waveguide damping, is currently being developed. This system will be used for a major upgrade of the BESSY-II facility to the BESSY Variable Pulse Storage Ring (BESSY-VSR) for a next-generation storage-ring light source. We will discuss the concept, challenges and designs for BESSY-VSR.

Slides TUAA03 [2.103 MB]

Export •

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

TUPB002

Elimination of High Frequency Noise From the Beam in the Diamond Light Source Storage Ring

operation, synchrotron, controls, power-supply

525

C. Christou, A. Bogusz, P.J. Marten
DLS, Oxfordshire, United Kingdom

High frequency beam motion has been identified as a source of noise in infrared beamlines in a number of synchrotron light sources. Diamond is a third generation synchrotron light source with storage ring current maintained by two superconducting CESR-B cavities powered by IOT-driven RF amplifiers. In our case, undesirable beam motion in the kilohertz range is predominantly driven by spectral content in the voltage across the IOTs arising from the switched mode nature of the high voltage power supply. Spectral noise on the amplifiers and beam has been identified and characterised and efforts to eliminate this noise are described. Care has been taken to maintain the overall stability of the RF at Diamond and tests have been carried out on an infrared beamline to investigate the degree to which beam noise impacts beamline operation in its different operating configurations.

Export •

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

TUPB006

The CLS SRF Cryogenic System Upgrade

cryomodule, cavity, SRF, cryogenics

539

C.N. Regier
CLS, Saskatoon, Saskatchewan, Canada

The Canadian Light Source currently makes use of a 500 MHz CESR-B type SRF cavity in its storage ring. While the performance of this cavity has generally been good, the reliability of the cryostat and cryogenic system has suffered a few setbacks over the 10 years of operation. The position of CLS as a user facility requires reliable beam to be consistently delivered. For this reason CLS is undertaking an upgrade project to improve system reliability and reduce downtime due to planned and unplanned maintenance. The upgrade is to include a redundant helium compressor, and new cryogenic infrastructure. In addition, the spare CESR-B cryomodule will be installed and operating in the storage ring. This talk reviews the problems with the current system to date, and discusses the proposals for the upgrade of the system.

Poster TUPB006 [0.622 MB]

Export •

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

THPB088

20 kW CW Power Couplers for the APS-U Harmonic Cavity

cavity, Windows, operation, electron

1346

M.P. Kelly, A. Barcikowski, Z.A. Conway, D. Horan, M. Kedzie, S.H. Kim, P.N. Ostroumov
ANL, Argonne, Illinois, USA
S.V. Kutsaev
RadiaBeam, Santa Monica, California, USA
J. Rathke
AES, Medford, New York, USA

Funding: This work supported by the U.S. DOE, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357. This research used resources of ANL’s ATLAS facility, which is a DOE Office of Science User Facility.
A pair of 20 kW CW adjustable RF power couplers optimized for 1.4 GHz have been designed and are being built as part of the APS-U bunch lengthening system. The system uses one superconducting RF cavity to be installed into the APS Upgrade electron storage ring and will provide a tremendous practical benefit to the majority of users by increasing the beam lifetime by 2-3 times. The 80 mm diameter, 50 Ω coaxial couplers include 4 cm (~20 dB) of adjustability. This allows optimization of bunch lengthening for a range of storage ring beam currents and fill patterns while, simultaneously, maintaining the required 0.84 MV harmonic cavity voltage. To provide bunch lengthening, the cavity/coupler system must extract RF power (up to 32 kW) from the beam. Each coupler will transmit roughly half of the total extracted power to external water-cooled loads. The design extends upon on a well-tested ANL two RF window concept, using a pair of simple rugged 80 mm diameter alumina disks. A new feature is the ‘hourglass-shaped’ inner conductor chosen to maximize transmission at 1.4 GHz. Results of electromagnetic and thermal simulations, as well as, prototyping and initial RF testing are presented.

Export •

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