2011 Particle Accelerator Conference - List of Keywords (superconducting-cavity)

Paper	Title	Other Keywords	Page
MOP290	Self Excited Operation for a 1.3 GHz 5-cell Superconducting Cavity	cavity, controls, TRIUMF, feedback	660
	K. Fong, M.P. Laverty, Q. Zheng TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada E.P. Chojnacki, G.H. Hoffstaetter, D. Meidlinger, S.P. Wang CLASSE, Ithaca, New York, USA
	Self-Excited operation of a resonant system does not require any external frequency tracking as the frequency is determined by the phase lag of the self-excited loop, it is therefore particularly useful for testing high Q RF cavities that do not have an automatic tuning mechanism. Self-exited operation has long been shown to work with single-cell cavities. We have recently demonstrated that it is also possible for multi-cell cavities, where multiple resonant modes are present. The Cornell 1.3 GHz 5-cell superconducting cavities was operated using Self-Excited operation and we were able to lock to the accelerating (pi) mode, despite the presence of neighbouring modes that are less than 10 MHz away. By means of the loops phase advance, we were able to select which mode was excited.

TUP163	Design Construction and Test Results of a HTS Solenoid for Energy Recovery Linac	solenoid, cavity, focusing, linac	1127
	R.C. Gupta, M. Anerella, I. Ben-Zvi, G. Ganetis, D. Kayran, G.T. McIntyre, J.F. Muratore, S.R. Plate, W. Sampson BNL, Upton, Long Island, New York, USA M.D. Cole, D. Holmes AES, Medford, NY, USA
	Funding: This work is supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886. An innovative feature of the proposed Energy Recovery Linac (ERL) at Brookhaven National Laboratory (BNL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS in the solenoid offers many advantages. The solenoid is located in the transition region (4 K to room temperature) where the temperature is too high for a conventional low temperature superconductor and the heat load on the cryogenic system too high for copper coils. Proximity to the cavity provides early focusing and thus a reduction in the emittance of the electron beam. In addition, taking full advantage of the high critical temperature of HTS, the solenoid has been designed to reach the required field at ~77 K, which can be obtained with liquid nitrogen. This significantly reduces the cost of testing and allows a variety of critical pre‐tests (e.g. measurements of the axial and fringe fields) which would have been very expensive at 4 K in liquid helium because of the additional requirements for a cryostat and associated facilities. This paper will present the design, construction, test results and current status of this HTS solenoid.

WEP170	Inspection Camera for Superconducting Cavity at IHEP	cavity, background, focusing, brightness	1808
	Z.C. Liu, J. Gao, Z.Q. Li IHEP Beijing, Beijing, People's Republic of China
	The first 1.3GHz low-loss large grain 9-cell superconducting cavity for ILC was fabricated at the Institute of High Energy Physics (IHEP) in April, 2010. The gradient of the cavity reached 20MV/m on the first vertical test in KEK in June, 2010. The gradient was limited by quench and field emission of the ninth-cell of the cavity. To locate the position of defects and improve surface processing, we have developed a high resolution inspection camera for the 1.3GHz 9-cell superconducting cavity of IHEP to check the cavity surface and make comparison. The camera is suitable for single and multi-cell 1.3GHz superconducting cavities. As there are several types of cavity under developing in IHEP, the camera was designed to be suitable for different type and frequency cavities like 500MHz BEPC II superconducting cavity, 1.3GHz TESLA and TESLA-like cavity, 1.3GHz and 650MHz low-beta cavity.

Paper

Title

Other Keywords

Page

MOP290

Self Excited Operation for a 1.3 GHz 5-cell Superconducting Cavity

cavity, controls, TRIUMF, feedback

660

K. Fong, M.P. Laverty, Q. Zheng
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
E.P. Chojnacki, G.H. Hoffstaetter, D. Meidlinger, S.P. Wang
CLASSE, Ithaca, New York, USA

Self-Excited operation of a resonant system does not require any external frequency tracking as the frequency is determined by the phase lag of the self-excited loop, it is therefore particularly useful for testing high Q RF cavities that do not have an automatic tuning mechanism. Self-exited operation has long been shown to work with single-cell cavities. We have recently demonstrated that it is also possible for multi-cell cavities, where multiple resonant modes are present. The Cornell 1.3 GHz 5-cell superconducting cavities was operated using Self-Excited operation and we were able to lock to the accelerating (pi) mode, despite the presence of neighbouring modes that are less than 10 MHz away. By means of the loops phase advance, we were able to select which mode was excited.

TUP163

Design Construction and Test Results of a HTS Solenoid for Energy Recovery Linac

solenoid, cavity, focusing, linac

1127

R.C. Gupta, M. Anerella, I. Ben-Zvi, G. Ganetis, D. Kayran, G.T. McIntyre, J.F. Muratore, S.R. Plate, W. Sampson
BNL, Upton, Long Island, New York, USA
M.D. Cole, D. Holmes
AES, Medford, NY, USA

Funding: This work is supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.
An innovative feature of the proposed Energy Recovery Linac (ERL) at Brookhaven National Laboratory (BNL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS in the solenoid offers many advantages. The solenoid is located in the transition region (4 K to room temperature) where the temperature is too high for a conventional low temperature superconductor and the heat load on the cryogenic system too high for copper coils. Proximity to the cavity provides early focusing and thus a reduction in the emittance of the electron beam. In addition, taking full advantage of the high critical temperature of HTS, the solenoid has been designed to reach the required field at ~77 K, which can be obtained with liquid nitrogen. This significantly reduces the cost of testing and allows a variety of critical pre‐tests (e.g. measurements of the axial and fringe fields) which would have been very expensive at 4 K in liquid helium because of the additional requirements for a cryostat and associated facilities. This paper will present the design, construction, test results and current status of this HTS solenoid.

WEP170

Inspection Camera for Superconducting Cavity at IHEP

cavity, background, focusing, brightness

1808

Z.C. Liu, J. Gao, Z.Q. Li
IHEP Beijing, Beijing, People's Republic of China

The first 1.3GHz low-loss large grain 9-cell superconducting cavity for ILC was fabricated at the Institute of High Energy Physics (IHEP) in April, 2010. The gradient of the cavity reached 20MV/m on the first vertical test in KEK in June, 2010. The gradient was limited by quench and field emission of the ninth-cell of the cavity. To locate the position of defects and improve surface processing, we have developed a high resolution inspection camera for the 1.3GHz 9-cell superconducting cavity of IHEP to check the cavity surface and make comparison. The camera is suitable for single and multi-cell 1.3GHz superconducting cavities. As there are several types of cavity under developing in IHEP, the camera was designed to be suitable for different type and frequency cavities like 500MHz BEPC II superconducting cavity, 1.3GHz TESLA and TESLA-like cavity, 1.3GHz and 650MHz low-beta cavity.