IPAC2012 - List of Authors (He, Y.)

Paper	Title	Page
MOPPP026	Cryogenic Distribution System for the Proposed Cornell ERL Main Linac	619
	E.N. Smith Cornell University, Ithaca, New York, USA Y. He, G.H. Hoffstaetter, M. Liepe, M. Tigner CLASSE, Ithaca, New York, USA
	Funding: This material is based upon work supported by the National Science Foundation under Grant No. DMR-0807731. The proposed Cornell ERL main linac requires a total cooling power of nearly 8kW at 1.8K, 5kW at 5K and over 100kW at 80K. This is distributed over approximately 65 cryomodules, each containing 6 rf cavities and associated input couplers and higher order mode absorbers. situated in two underground tunnels. While the total heat load is comparable to that for each of the 8 individual LHC cryoplants, the very high ratio of dynamic heat load to static heat load, combined with the high power density at various sites produces interesting challenges for the cryogenic distribution system. A schematic view of the design choices selected, some of which are different from existing large cryogenic systems, and the basis for these decisions, is presented in this paper.

WEPPC073	Progress on Superconducting RF Work for the Cornell ERL	2381
	M. Liepe, F. Furuta, G.M. Ge, Y. He, G.H. Hoffstaetter, T.I. O'Connell, S. Posen, J. Sears, M. Tigner, N.R.A. Valles, V. Veshcherevich CLASSE, Ithaca, New York, USA
	Cornell University is developing the superconducting RF technology required for the construction of a 100 mA hard X-ray light source driven by an Energy-Recovery Linac. Prototypes of all beam line components of the 5 GeV cw SRF main linac cryomodule have been fabricated and tested in detail. This work includes an optimized 7-cell SRF cavity, a broadband HOM beamline absorber, a cold frequency tuner, and a 5 kW CW RF input coupler. A one-cavity test cryomodule has been assembled for a first full cryomodule test of the main linac cavity, and is currently under testing. In this paper we give an overview of these extensive R&D activities at Cornell.

WEPPC075	Testing of the Main-Linac Prototype Cavity in a Horizontal Test Cryomodule for the Cornell ERL	2387
	N.R.A. Valles, F. Furuta, G.M. Ge, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, S. Posen, P. Quigley, J. Sears, M. Tigner, V. Veshcherevich CLASSE, Ithaca, New York, USA
	Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac (ERL). The cavity construction met all necessary fabrication constraints. After a bulk BCP, 650C outgassing, final BCP, and 120C bake the cavity was vertically tested. The cavity met quality factor and gradient specifications (2·10¹⁰ at 16.2 MV/m) in the vertical test. Progressing with the ERL linac development, the cavity was installed in a horizontal test cryomodule and the quality factor versus accelerating gradient was again measured. This baseline measurement is the first test in a sequence of tests of the main linac cavity in the test cryomodule. Subsequent tests will be with increased complexity of the beam line, e.g. with HOM beamline loads installed, to study potential sources of reducing the cavity’s quality factor.

THPPP041	A CW High Charge State Heavy Ion RFQ Accelerator for SSC-LINAC Injector	3826
	G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, Q.F. Zhou, K. Zhu PKU/IHIP, Beijing, People's Republic of China Y. He, C. Xiao, Y.Q. Yang, Y.J. Yuan, H.W. Zhao IMP, Lanzhou, People's Republic of China
	Funding: Supported by NSFC(11079001). The cooler storage ring synchrotron CSR of HIRFL started running in 2008. The SFC (Sector Focusing Cyclotron) and SSC (Separator Sector Cyclotron) form an injector for the CSR. To improve beam intensity and/or injection efficiency, a new linear injector, the SSC-LINAC, for the SSC has been proposed to replace the existing SFC. The SSC-LINAC consists of an ECR ion source, LEBT, a RFQ, MEBT, and four IH-DTLs. This paper only represents the design research of the RFQ accelerator, which has a frequency of 53.667MHz. The ions up to uranium with ratio of mass-to-charge up to 7 are accelerated and injected into the CSR by the SSC-LINAC. The SSC-LINAC works on CW mode. The RFQ beam dynamic design study is based on 238U³⁴⁺ beams with intensity of 0.5mA. The inter-vane voltage is 70kV with a maximum modulation factor of 1.93. It uses a 2.5m-long 4-rod structure to accelerate uranium ions from 3.728keV/u to 143keV/u with transmission efficiency of 94%. The RFQDYN code checks the transmission of different kinds of ions in the RFQ. The specific shunt impedance of RFQ is optimized to 438kΩ.m. The design of cavity tuning and the water cooling system are also included in this paper. Corresponding authors: yrlu@pku.edu.cn, hey@impcas.ac.cn

THPPC014	Commissioning Status of the 3 MeV RFQ for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University	3305
	Q.Z. Xing, Y.J. Bai, D.T. Bin, J.C. Cai, C. Cheng, L. Du, Q. Du, C. Jiang, Q. Qiang, D. Wang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China J.H. Billen TechSource, Santa Fe, New Mexico, USA W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China X.L. Guan Tsinghua University, Beijing, People's Republic of China J. Stovall CERN, Geneva, Switzerland L.M. Young AES, Medford, NY, USA
	Funding: Work supported by the “985 Project” of the Ministry of Education of China. We present, in this paper, the commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In 2012 the 3-meter-long RFQ will deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. Braze of the vanes was completed in September, 2011. The final field tuning of the whole cavity was completed in October, 2011. Initial commissioning will be underway at the beginning of 2012.

Paper

Title

Page

Cryogenic Distribution System for the Proposed Cornell ERL Main Linac

619

E.N. Smith
Cornell University, Ithaca, New York, USA
Y. He, G.H. Hoffstaetter, M. Liepe, M. Tigner
CLASSE, Ithaca, New York, USA

Funding: This material is based upon work supported by the National Science Foundation under Grant No. DMR-0807731.
The proposed Cornell ERL main linac requires a total cooling power of nearly 8kW at 1.8K, 5kW at 5K and over 100kW at 80K. This is distributed over approximately 65 cryomodules, each containing 6 rf cavities and associated input couplers and higher order mode absorbers. situated in two underground tunnels. While the total heat load is comparable to that for each of the 8 individual LHC cryoplants, the very high ratio of dynamic heat load to static heat load, combined with the high power density at various sites produces interesting challenges for the cryogenic distribution system. A schematic view of the design choices selected, some of which are different from existing large cryogenic systems, and the basis for these decisions, is presented in this paper.

WEPPC073

Progress on Superconducting RF Work for the Cornell ERL

2381

M. Liepe, F. Furuta, G.M. Ge, Y. He, G.H. Hoffstaetter, T.I. O'Connell, S. Posen, J. Sears, M. Tigner, N.R.A. Valles, V. Veshcherevich
CLASSE, Ithaca, New York, USA

Cornell University is developing the superconducting RF technology required for the construction of a 100 mA hard X-ray light source driven by an Energy-Recovery Linac. Prototypes of all beam line components of the 5 GeV cw SRF main linac cryomodule have been fabricated and tested in detail. This work includes an optimized 7-cell SRF cavity, a broadband HOM beamline absorber, a cold frequency tuner, and a 5 kW CW RF input coupler. A one-cavity test cryomodule has been assembled for a first full cryomodule test of the main linac cavity, and is currently under testing. In this paper we give an overview of these extensive R&D activities at Cornell.

WEPPC075

Testing of the Main-Linac Prototype Cavity in a Horizontal Test Cryomodule for the Cornell ERL

2387

N.R.A. Valles, F. Furuta, G.M. Ge, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, S. Posen, P. Quigley, J. Sears, M. Tigner, V. Veshcherevich
CLASSE, Ithaca, New York, USA

Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac (ERL). The cavity construction met all necessary fabrication constraints. After a bulk BCP, 650C outgassing, final BCP, and 120C bake the cavity was vertically tested. The cavity met quality factor and gradient specifications (2·10¹⁰ at 16.2 MV/m) in the vertical test. Progressing with the ERL linac development, the cavity was installed in a horizontal test cryomodule and the quality factor versus accelerating gradient was again measured. This baseline measurement is the first test in a sequence of tests of the main linac cavity in the test cryomodule. Subsequent tests will be with increased complexity of the beam line, e.g. with HOM beamline loads installed, to study potential sources of reducing the cavity’s quality factor.

THPPP041

A CW High Charge State Heavy Ion RFQ Accelerator for SSC-LINAC Injector

3826

G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, Q.F. Zhou, K. Zhu
PKU/IHIP, Beijing, People's Republic of China
Y. He, C. Xiao, Y.Q. Yang, Y.J. Yuan, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: Supported by NSFC(11079001).
The cooler storage ring synchrotron CSR of HIRFL started running in 2008. The SFC (Sector Focusing Cyclotron) and SSC (Separator Sector Cyclotron) form an injector for the CSR. To improve beam intensity and/or injection efficiency, a new linear injector, the SSC-LINAC, for the SSC has been proposed to replace the existing SFC. The SSC-LINAC consists of an ECR ion source, LEBT, a RFQ, MEBT, and four IH-DTLs. This paper only represents the design research of the RFQ accelerator, which has a frequency of 53.667MHz. The ions up to uranium with ratio of mass-to-charge up to 7 are accelerated and injected into the CSR by the SSC-LINAC. The SSC-LINAC works on CW mode. The RFQ beam dynamic design study is based on 238U³⁴⁺ beams with intensity of 0.5mA. The inter-vane voltage is 70kV with a maximum modulation factor of 1.93. It uses a 2.5m-long 4-rod structure to accelerate uranium ions from 3.728keV/u to 143keV/u with transmission efficiency of 94%. The RFQDYN code checks the transmission of different kinds of ions in the RFQ. The specific shunt impedance of RFQ is optimized to 438kΩ.m. The design of cavity tuning and the water cooling system are also included in this paper.
Corresponding authors: yrlu@pku.edu.cn, hey@impcas.ac.cn

THPPC014

Commissioning Status of the 3 MeV RFQ for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University

3305

Q.Z. Xing, Y.J. Bai, D.T. Bin, J.C. Cai, C. Cheng, L. Du, Q. Du, C. Jiang, Q. Qiang, D. Wang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
J.H. Billen
TechSource, Santa Fe, New Mexico, USA
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
X.L. Guan
Tsinghua University, Beijing, People's Republic of China
J. Stovall
CERN, Geneva, Switzerland
L.M. Young
AES, Medford, NY, USA

Funding: Work supported by the “985 Project” of the Ministry of Education of China.
We present, in this paper, the commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In 2012 the 3-meter-long RFQ will deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. Braze of the vanes was completed in September, 2011. The final field tuning of the whole cavity was completed in October, 2011. Initial commissioning will be underway at the beginning of 2012.