SRF2015 - List of Authors (Gao, J.)

Paper	Title	Page
MOPB070	Preliminary Conceptual Design of the CEPC SRF System	272
	J.Y. Zhai, J. Gao, T.M. Huang, Z.C. Liu, Z.H. Mi, P. Sha, Y. Sun, H.J. Zheng IHEP, Beijing, People's Republic of China S.A. Belomestnykh BNL, Upton, Long Island, New York, USA S.A. Belomestnykh Stony Brook University, Stony Brook, USA C. Pagani INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	CEPC is a circular electron positron collider operating at 240 GeV center-of-mass energy as a Higgs factory, recently proposed by the Chinese high energy physics community. The CEPC study group, together with the FCC and ILC community, will contribute to the development of future high energy colliders and experiments which will ensure that the elementary particle physics remain a vibrant and exciting field of fundamental investigation for decades to come. Superconducting RF (SRF) system is one of the most important technical systems of CEPC and is a key to achieving its design energy and luminosity. It will dominate, with the associated RF power source and cryogenic system, the overall machine cost, efficiency and performance. The CEPC SRF system will be one of the largest and most powerful SRF accelerator installations in the world. The preliminary conceptual design of the CEPC SRF system is summarized in this paper, including the machine layout, key parameter choices and some critical issues such as HOM damping, emphasizing the new technology requirement and R&D focuses.
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TUPB017	1.3 GHz SRF Technology R&D Progress of IHEP	581
	J.Y. Zhai, Y.L. Chi, J.P. Dai, X.W. Dai, J. Gao, R. Ge, D.Y. He, T.M. Huang, X. Huang, S. Jin, S.P. Li, H.Y. Lin, B. Liu, Z.C. Liu, Q. Ma, Z.H. Mi, W.M. Pan, X.H. Peng, L.R. Sun, Y. Sun, Z. Xue, S.W. Zhang, Z. Zhang, H. Zhao, T.X. Zhao, H.J. Zheng, Z.S. Zhou IHEP, Beijing, People's Republic of China
	IHEP started the 1.3GHz SRF technology R&D in 2006 and recently enters the stage of integration and industrialization. After successfully making several single cell and 9-cell cavities of different shape and material, we designed and assembled a short cryomodule containing one large grain low loss shape 9-cell cavity with an input coupler and a tuner etc. This module will perform horizontal test in 2016 with the newly commissioned 1.3GHz 5MW klystron and the 2K cryogenic system. Beam test with a DC photocathode gun is also foreseen in the near future. We report here the problems, key findings and improvements in cavity dressing, clean room assembly, cryomodule assembly and the liquid nitrogen cool down test. A fine grain TESLA 9-cell cavity is also under fabrication in a company as the industrialization study.
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THPB004	HOM Calculations for Different Cavities and Beam Induced HOM Power Analysis of ESS	1061
	H.J. Zheng, J. Gao IHEP, Beijing, People's Republic of China J.F. Chen INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	For different design of ESS superconducting cavities, the higher order modes (HOM's) of monopoles, dipoles, quadrupoles and sextupoles are found. Their R/Q values are also calculated. Main HOM related issues are the beam instabilities and the HOM induced power especially from TM monopoles. The analysis for the beam induced HOM voltage and power in this paper showed that, if the HOM frequency is a few kHz away from the beam spectrum, it is not a problem. In order to understand the effects of the beam structure, analytic expressions are developed. With these expressions, the induced HOM voltage and power were calculated by assuming external Q for each HOM. Our analysis confirm that, with thebeam structure of ESS and a good cavity design, no special tight tolerances are required for cavity fabrication and no HOM couplers in the cavity beam pipes are planned.
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Paper

Title

Page

Preliminary Conceptual Design of the CEPC SRF System

272

J.Y. Zhai, J. Gao, T.M. Huang, Z.C. Liu, Z.H. Mi, P. Sha, Y. Sun, H.J. Zheng
IHEP, Beijing, People's Republic of China
S.A. Belomestnykh
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh
Stony Brook University, Stony Brook, USA
C. Pagani
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

CEPC is a circular electron positron collider operating at 240 GeV center-of-mass energy as a Higgs factory, recently proposed by the Chinese high energy physics community. The CEPC study group, together with the FCC and ILC community, will contribute to the development of future high energy colliders and experiments which will ensure that the elementary particle physics remain a vibrant and exciting field of fundamental investigation for decades to come. Superconducting RF (SRF) system is one of the most important technical systems of CEPC and is a key to achieving its design energy and luminosity. It will dominate, with the associated RF power source and cryogenic system, the overall machine cost, efficiency and performance. The CEPC SRF system will be one of the largest and most powerful SRF accelerator installations in the world. The preliminary conceptual design of the CEPC SRF system is summarized in this paper, including the machine layout, key parameter choices and some critical issues such as HOM damping, emphasizing the new technology requirement and R&D focuses.

Export •

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

TUPB017

1.3 GHz SRF Technology R&D Progress of IHEP

581

J.Y. Zhai, Y.L. Chi, J.P. Dai, X.W. Dai, J. Gao, R. Ge, D.Y. He, T.M. Huang, X. Huang, S. Jin, S.P. Li, H.Y. Lin, B. Liu, Z.C. Liu, Q. Ma, Z.H. Mi, W.M. Pan, X.H. Peng, L.R. Sun, Y. Sun, Z. Xue, S.W. Zhang, Z. Zhang, H. Zhao, T.X. Zhao, H.J. Zheng, Z.S. Zhou
IHEP, Beijing, People's Republic of China

IHEP started the 1.3GHz SRF technology R&D in 2006 and recently enters the stage of integration and industrialization. After successfully making several single cell and 9-cell cavities of different shape and material, we designed and assembled a short cryomodule containing one large grain low loss shape 9-cell cavity with an input coupler and a tuner etc. This module will perform horizontal test in 2016 with the newly commissioned 1.3GHz 5MW klystron and the 2K cryogenic system. Beam test with a DC photocathode gun is also foreseen in the near future. We report here the problems, key findings and improvements in cavity dressing, clean room assembly, cryomodule assembly and the liquid nitrogen cool down test. A fine grain TESLA 9-cell cavity is also under fabrication in a company as the industrialization study.

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

THPB004

HOM Calculations for Different Cavities and Beam Induced HOM Power Analysis of ESS

1061

H.J. Zheng, J. Gao
IHEP, Beijing, People's Republic of China
J.F. Chen
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

For different design of ESS superconducting cavities, the higher order modes (HOM's) of monopoles, dipoles, quadrupoles and sextupoles are found. Their R/Q values are also calculated. Main HOM related issues are the beam instabilities and the HOM induced power especially from TM monopoles. The analysis for the beam induced HOM voltage and power in this paper showed that, if the HOM frequency is a few kHz away from the beam spectrum, it is not a problem. In order to understand the effects of the beam structure, analytic expressions are developed. With these expressions, the induced HOM voltage and power were calculated by assuming external Q for each HOM. Our analysis confirm that, with thebeam structure of ESS and a good cavity design, no special tight tolerances are required for cavity fabrication and no HOM couplers in the cavity beam pipes are planned.

Export •

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