Author: Lu, Y.R.
Paper Title Page
MOPEA039 Beam Commissioning and Neutron Radiography on a High Current Deuteron RFQ 163
 
  • Y.R. Lu, J. Chen, J.E. Chen, S.L. Gao, Z.Y. Guo, F.J. Jia, G. Liu, S.X. Peng, H.T. Ren, W.L. Xia, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • S.Q. Liu, S. Wang, J. Zhao, B.Y. Zou
    State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China
  
  Funding: Supported by NSFC 11079001 and Peking University
The high current deuteron RFQ has been developed and widely used in many projects, especially for accelerator based neutron source and its application. This paper reviews not only the recent developments in the world wide, also presents the beam dynamics, structure design ,RF full power test, beam commissioning of PKUNIFTY, which is consisted of a high current very compact ECR source, a 201.5MHz four-rod deuteron RFQ, thicker beryllium target and its moderating, collimation and neutron radiography system. RF and beam commissioning with duty cycle of 4% show the RFQ inter-vane voltage reaches 70kV at about 240kW, the delivered deuteron peak beam current is about 12mA at 290kW with the beam transmission of about 60%. The improvement of transmission is going on. The initial neutron radiography commissioning has been carried out. The results will promote the future development of small accelerator based neutron source. 		 
 
TUODB202 Experiment and Numerical Simulation Results of Plasma Window 1155
 
  • K. Zhu, S. Huang, Y.R. Lu, B.L. Shi
    PKU, Beijing, People's Republic of China
  
  Funding: Supported by NSFC 91026012
A windowless vacuum seal technique has been widely researched and designed, which can connect high pressure cavity to a vacuum condition with rather little thickness of material. As a result, it will reduce most interaction with the particle beam penetrating through comparing to that of foil window. It is desired extensively in experiments using high-intensity heavy ion beams which will break foil window in a short time or in experiments which require the injecting beams with mono-energy and high purity for example. In this work, we study the plasma window in argon which is used as a windowless vacuum sealing device. A numerical 2D FLUENT-based magneto-hydrodynamic model has been developed to investigate the physical reasons of high pressure difference in plasma window. Further, preliminary experimental results are presented and discussed. 		 
slides icon Slides TUODB202 [2.180 MB]  
 
TUPEA018 Recent Progress of Laser Plasma Proton Accelerator at Peking University 1199
 
  • X.Q. Yan, J.E. Chen, H.Z. Fu, Y.X. Geng, Z.Y. Guo, C. Lin, Y.R. Lu, Y. Shang, Z.X. Yuan, S. Zhao, K. Zhu
    PKU, Beijing, People's Republic of China
  
  Funding: National Natural Science Foundation of China (Grant Nos.10935002, 10835003, 11025523)
Recent a project called Laser plasma Proton Accelerator (LAPA) is approved by MOST in China. A prototype of laser driven proton accelerator (1~15MeV) based on the PSA mechanism and plasma lens is going to be built at Peking University in the next five years. It can be used for the applications such as cancer therapy, plasma imaging and fast ignition for inertial confine fusion. The recent progress of LAPA is reported here. 		 
 
TUPWA022 Beam Dynamics Design of a 325 MHz RFQ 1772
 
  • F.J. Jia, J.E. Chen, G. Liu, Y.R. Lu, X.Q. Yan
    PKU, Beijing, People's Republic of China
  • B.Q. Cui, J.H. Li, G.H. Wei
    CIAE, Beijing, People's Republic of China
  
  The beam dynamic design of a 325 MHz Radio Frequency Quadrupole (RFQ) is presented in this paper. This 4-vane RFQ will accelerate pulsed proton beam from 30 keV to 3 MeV with repetition frequency of 1 MHz. A 1 MHz chopper and a 5 MHz buncher are arranged in the Low-Energy-Beam-Transport (LEBT) to produce the injected beam. The beam length at the RFQ entrance is about 3 ns, and the energy-spread is about 10%. The code of PARMTEQM is used to simulate RFQ structure. The design should realize high transmission for very high intensity beam meanwhile low emittance growth and relatively short length should be kept.  
 
TUPWA023 Design of the Tuning System for the He+ Coupled RFQ-SFRFQ Cavity 1775
 
  • W.L. Xia, J.E. Chen, S.L. Gao, Z.Y. Guo, Y.R. Lu, S.X. Peng, Z. Wang, X.Q. Yan, J. Zhao, K. Zhu
    PKU, Beijing, People's Republic of China
  
  Funding: Supported by NSFC 10905003, 11079001, 91026012 Corresponding author: wangzhi@pku.edu.cn
The CRS (coupled RFQ-SFRFQ) cavity is a new type linac that couples traditional RFQ (radio frequency quadrupole) and SFRFQ (separated function RFQ) electrodes into a single cavity. The overall design of the CRS cavity has been completed and the linac is being manufactured currently. In this paper, we aimed to design a frequency tuning system for the CRS cavity, which will be used to explore the electromagnetic field distribution between RFQ and SFRFQ sections in the cavity. The frequency range, variation of Q value, power consumption and electric field distribution were investigated. Based on the beam dynamic program SFRFQDYNv1.0, we analysed the beam transmission properties of the cavity under the unbalanced electric field distribution. The optimized parameters of the tuning system were obtained. 		 
 
THPWO047 The LLRF Measurement and Analysis of the SSC-LINAC RFQ 3875
 
  • G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • X. Du, Y. He, G. Pan, Y.Q. Yang, X. Yin, Y.J. Yuan, Z.L. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  
  Funding: Supported by NSFC(11079001)
The manufacturing process of the SSC-LINAC RFQ went to end and the LLRF measurement has been done. The frequency of the RFQ is 53.557 MHz without tuning, which is not far from the design value 53.667 MHz. The unflatness of the field along the beam axis is less than ±4%, which meets the simulation results. The dipole field is in the acceptable margin as well. The frequency will be adjusted by tuning plungers in operation. In this paper, the field distribution along the cavity has been measured and compared with the modulated electrodes simulation. The difference and its influences on the beam transmission have been analyzed. 		 
 
THPWO048 A CW High Charge State Heavy Ion RFQ for SSC-LINAC 3878
 
  • Y.R. Lu, J.E. Chen, S.L. Gao, G. Liu, Z. Wang, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • Y. He, L.P. Sun, J.W. Xia, Y.Q. Yang, X. Yin, Y.J. Yuan, Z.L. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  
  Funding: Supported by NSFC 11079001
To improve the super heavy ion beam injection efficiency and supply high current heavy ion beam for Separated Sector Cyclotron, A CW RFQ for heavy ion with high charge state has been designed and manufactured in the last two years. This RFQ will operate at 53.667MHz, will accelerate super heavy ions such as 238U34+ to 143keV/u. This paper will introduce the SSC-LINAC components, especially the RFQ beam dynamics, full length structure design, tuning and cooling method. Furthermore RF system and RF commissioning with full power for the RFQ power cavity will also be presented.