IPAC2011 - List of Authors (Chi, Y.L.)

Paper

Title

Page

Beam Dynamics Studies on the 100 MeV/100 kW Electron Linear Accelerator for NSC KIPT Neutron Source

673

S. Pei, Y.L. Chi, M. Hou, W.B. Liu, G. Pei, S.H. Wang, Z.S. Zhou
IHEP Beijing, Beijing, People's Republic of China
N. Aizatsky, I.M. Karnaukhov, V.A. Kushnir, V. Mitrochenco, A.Y. Zelinsky
NSC/KIPT, Kharkov, Ukraine

We designed one 100MeV/100kW electron linear accelerator for NSC KIPT, which will be used to drive a neutron source on the base of subcritical assembly. Beam dynamics studies has been conducted to reach the design requirement (E=100MeV, P=100kW, dE/E<1% for 99% particles). In this paper, we will present the progress of the design and dynamics simulation results. For high intensity and long beam pulse linear accelerators, BBU effect is one big issue; special care has been taken in the accelerating structure design. To satisfy the energy spread requirement at the linac exit, the particles with large energy difference from the synchronous particle should be eliminated at low energy stage to ease the design of the collimation system and radiation shielding. A dispersion free chicane with 4 bending magnets is introduced at the downstream of the 1st accelerating section; the unwanted particles will be collimated there.

TUXA01

Status and Challenges of the China Spallation Neutron Source

889

S. Fu, H. Chen, Y.W. Chen, Y.L. Chi, H. Dong, L. Dong, S.X. Fang, K.X. Huang, W. Kang, J. Li, L. Ma, H.F. Ouyang, H. Qu, H. Sun, J. Tang, C.H. Wang, Q.B. Wang, S. Wang, T.G. Xu, Z.X. Xu, X. Yin, C. Zhang, J. Zhang
IHEP Beijing, Beijing, People's Republic of China

The accelerator complex of China Spallation Neutron Source (CSNS) mainly consists of an H⁻ linac of 80 MeV and a rapid-cycling synchrotron of 1.6 GeV. It operates at 25 Hz repetition rate with an initial proton beam power of 100 kW and is upgradeable to 500kW. The project will start construction in the middle of 2011 with a construction period of 6.5 years. The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges. This paper presents the current status of CSNS project and summarizes the technology development during the past several years.

Slides TUXA01 [3.444 MB]

TUPC034

Design Studies on 100 MeV/100 kW Electron Linac for NSC KIPT Neutron Source on the Base of Subcritical Assembly Driven by Linac

1075

Y.L. Chi, J. Cao, X.W. Dai, C.D. Deng, M. Hou, X.C. Kong, R.L. Liu, W.B. Liu, C. Ma, G. Pei, H. Song, S.H. Wang, G. Xu, J. Zhao, Z.S. Zhou
IHEP Beijing, Beijing, People's Republic of China
M.I. Ayzatskiy, I.M. Karnaukhov, V.A. Kushnir, V.V. Mytrochenko, A.Y. Zelinsky
NSC/KIPT, Kharkov, Ukraine
S. Pei
IHEP Beijng, Beijing, People's Republic of China

In NSC KIPT, Kharkov, Ukraine, a neutron source on the base of subcritical assembly driven by 100 MeV/100 kW electron linear accelerator is under design and development. To provide neutron flux value of about 1013 neutron/s the electron linear accelerator with 100 MeV beam and average beam power of 100 kW will be used. Construction and manufacture of the linear accelerator of such high beam intensity with low emittance and beam losses is a challenging task. In the report the project of the electron linear accelerator of the required beam energy and intensity is described. The accelerator structure and main technical solutions are presented. To overcome the BBU effect of this high average beam current, several effective measures are adopt, such as using constant gradient structure to spread the HOMs frequencies different cells, larger inner radius and shorter section length make the higher group velocity and optimize the structure geometry to keep the shunt impedance as good as possible. After the beam bunching system, a chicane is followed to chopper the beam to avoid the beam lost in the higher energy part.

THPZ012

Luminosity Enhancement and Performance in BEPCII

3708

Q. Qin, J. Cao, J. Cheng, Y.L. Chi, H. Dong, Z. Duan, D. Ji, W. Kang, S.P. Li, L. Ma, H. Qu, C.H. Wang, G.W. Wang, J.Q. Wang, X.H. Wang, Y. Wei, J. Xing, G. Xu, C.H. Yu, J. Yue, C. Zhang, Y. Zhang
IHEP Beijing, Beijing, People's Republic of China

The Beijing Electron Positron Collider (BEPC) was upgraded to a factory-like machine –- BEPCII, during last several years. From last November, the BEPCII was commissioned again for its luminosity. Efforts on optics correction including optimizing the strengths of superconducting quadrupoles near the IP, orbits correction concerning beam energy, etc, make the transvers tunes possible to move very close to half integer, bringing a big luminosity increase. The background of the detector is also reduced with beam commissioning, and finally fit the requirements of data taking. Further luminosity commissioing, including coupling optimization, beta-waist tuning, was carried on, and the luminosity reached 6.49·10³² cm^-2 s^-1 during routine operation. Some measures of luminosity enhancement and the luminosity related accelerator physics issues will be discussed.

Paper	Title	Page
MOPS033	Beam Dynamics Studies on the 100 MeV/100 kW Electron Linear Accelerator for NSC KIPT Neutron Source	673
	S. Pei, Y.L. Chi, M. Hou, W.B. Liu, G. Pei, S.H. Wang, Z.S. Zhou IHEP Beijing, Beijing, People's Republic of China N. Aizatsky, I.M. Karnaukhov, V.A. Kushnir, V. Mitrochenco, A.Y. Zelinsky NSC/KIPT, Kharkov, Ukraine
	We designed one 100MeV/100kW electron linear accelerator for NSC KIPT, which will be used to drive a neutron source on the base of subcritical assembly. Beam dynamics studies has been conducted to reach the design requirement (E=100MeV, P=100kW, dE/E<1% for 99% particles). In this paper, we will present the progress of the design and dynamics simulation results. For high intensity and long beam pulse linear accelerators, BBU effect is one big issue; special care has been taken in the accelerating structure design. To satisfy the energy spread requirement at the linac exit, the particles with large energy difference from the synchronous particle should be eliminated at low energy stage to ease the design of the collimation system and radiation shielding. A dispersion free chicane with 4 bending magnets is introduced at the downstream of the 1st accelerating section; the unwanted particles will be collimated there.

TUXA01	Status and Challenges of the China Spallation Neutron Source	889
	S. Fu, H. Chen, Y.W. Chen, Y.L. Chi, H. Dong, L. Dong, S.X. Fang, K.X. Huang, W. Kang, J. Li, L. Ma, H.F. Ouyang, H. Qu, H. Sun, J. Tang, C.H. Wang, Q.B. Wang, S. Wang, T.G. Xu, Z.X. Xu, X. Yin, C. Zhang, J. Zhang IHEP Beijing, Beijing, People's Republic of China
	The accelerator complex of China Spallation Neutron Source (CSNS) mainly consists of an H⁻ linac of 80 MeV and a rapid-cycling synchrotron of 1.6 GeV. It operates at 25 Hz repetition rate with an initial proton beam power of 100 kW and is upgradeable to 500kW. The project will start construction in the middle of 2011 with a construction period of 6.5 years. The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges. This paper presents the current status of CSNS project and summarizes the technology development during the past several years.
	Slides TUXA01 [3.444 MB]

TUPC034	Design Studies on 100 MeV/100 kW Electron Linac for NSC KIPT Neutron Source on the Base of Subcritical Assembly Driven by Linac	1075
	Y.L. Chi, J. Cao, X.W. Dai, C.D. Deng, M. Hou, X.C. Kong, R.L. Liu, W.B. Liu, C. Ma, G. Pei, H. Song, S.H. Wang, G. Xu, J. Zhao, Z.S. Zhou IHEP Beijing, Beijing, People's Republic of China M.I. Ayzatskiy, I.M. Karnaukhov, V.A. Kushnir, V.V. Mytrochenko, A.Y. Zelinsky NSC/KIPT, Kharkov, Ukraine S. Pei IHEP Beijng, Beijing, People's Republic of China
	In NSC KIPT, Kharkov, Ukraine, a neutron source on the base of subcritical assembly driven by 100 MeV/100 kW electron linear accelerator is under design and development. To provide neutron flux value of about 1013 neutron/s the electron linear accelerator with 100 MeV beam and average beam power of 100 kW will be used. Construction and manufacture of the linear accelerator of such high beam intensity with low emittance and beam losses is a challenging task. In the report the project of the electron linear accelerator of the required beam energy and intensity is described. The accelerator structure and main technical solutions are presented. To overcome the BBU effect of this high average beam current, several effective measures are adopt, such as using constant gradient structure to spread the HOMs frequencies different cells, larger inner radius and shorter section length make the higher group velocity and optimize the structure geometry to keep the shunt impedance as good as possible. After the beam bunching system, a chicane is followed to chopper the beam to avoid the beam lost in the higher energy part.

THPZ012	Luminosity Enhancement and Performance in BEPCII	3708
	Q. Qin, J. Cao, J. Cheng, Y.L. Chi, H. Dong, Z. Duan, D. Ji, W. Kang, S.P. Li, L. Ma, H. Qu, C.H. Wang, G.W. Wang, J.Q. Wang, X.H. Wang, Y. Wei, J. Xing, G. Xu, C.H. Yu, J. Yue, C. Zhang, Y. Zhang IHEP Beijing, Beijing, People's Republic of China
	The Beijing Electron Positron Collider (BEPC) was upgraded to a factory-like machine –- BEPCII, during last several years. From last November, the BEPCII was commissioned again for its luminosity. Efforts on optics correction including optimizing the strengths of superconducting quadrupoles near the IP, orbits correction concerning beam energy, etc, make the transvers tunes possible to move very close to half integer, bringing a big luminosity increase. The background of the detector is also reduced with beam commissioning, and finally fit the requirements of data taking. Further luminosity commissioing, including coupling optimization, beta-waist tuning, was carried on, and the luminosity reached 6.49·10³² cm^-2 s^-1 during routine operation. Some measures of luminosity enhancement and the luminosity related accelerator physics issues will be discussed.