Author: Peng, S.X.
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.
 
 
MOPFI033 Commissioning Results and Progress of a Helium Injector for Coupled RFQ and SFRFQ Project at Peking University 357
 
  • J. Chen, J.E. Chen, S.L. Gao, Z.Y. Guo, Y.T. Luo, S.X. Peng, H.T. Ren, Z. Wang, Z.H. Wang, W.L. Xia, Y. Xu, A.L. Zhang, T. Zhang, J. Zhao
    PKU, Beijing, People's Republic of China
 
  At Peking University (PKU) a new helium injector for coupled radio frequency quadrupole(RFQ) and separated function radio frequency quadrupole(SFRFQ) within one cavity, so called as coupled RFQ & SFRFQ, was designed recently*. It will provide a 30keV 20mA He+ beam whose emittance is less than 0.15 π.mm.mrad for the accelerator. It is a combination of a 2.45GHz PKU PMECRIS (Permanent Magnet ECRIS) and a 1.16 m long LEBT. Within the 1.16 m LEBT, 2 solenoids, 2 steering magnets, a kicker, a space charge compensation section, a collimator, two vacuum valves, a Faraday cup and an ACCT are installed. The manufacture has been completed and the commissioning is on the way. In this paper we will address the commissioning results and its progress.
* Haitao Ren, et al., A Helium Injector for Coupled RFQ and SFRFQ Cavity Project at Peking University. Proc. LINAC’12, Paper TUPB034, Israel, 2012
 
 
MOPFI034 First Intense H Beam Generated by a Microwave-driven Pure Volume Source 360
 
  • S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, H.T. Ren, Zh.W. Wang, Y. Xu, T. Zhang
    PKU, Beijing, People's Republic of China
  • A.L. Zhang
    Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
  • J. Zhao
    State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China
 
  The 2.45 GHz Electron cyclotron resonance (ECR) plasma generators have demonstrated their efficiency, reproducibility on producing H+, D+, O+, N+, He+, Ar+* and He2+ at Peking University(PKU). Recently, modifications on magnet field configuration, discharge chamber structure and extraction system have been done to set-up a microwave-driven pure volume H ion source. First experiment was done on PKU ion source test bench at the beginning of Nov, 2012. A 15 mA H ion beam has been produced at 40 keV by this prototype source. This paper describes the source principle and design in detail and reports on the current status of the development work.
* H. T. Ren, S. X. Peng*, P. N. Lu, S. Yan, Q. F. Zhou, J. Zhao, Z. X. Yuan, Z. Y. Guo and J. E. Chen, Rev. Sci. Instrum. 83, 02B905 (2012)
 
 
MOPFI035 Preliminary Results of H2+ Beam Generated by a 2.45 GHz Permanent Magnet ECR Ion Source at PKU 363
 
  • Y. Xu, J. Chen, J.E. Chen, Z.Y. Guo, Y.T. Luo, S.X. Peng, H.T. Ren, Z.H. Wang, T. Zhang, J. Zhao
    PKU, Beijing, People's Republic of China
  • A.L. Zhang
    Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
 
  Recently, the need to build an ion source generating high current hydrogen molecular ion H2+ beam has been growing rapidly. For example, H2+ ion can be used as a pilot beam of the intense deuteron beam during the commission phase of linear accelerators to minimize the activation of components. And it is an effective way to improve the output current of cyclotrons by accelerating H2+ and stripping it into H+ at the exit of accelerator, instead of accelerating H+ beam directly. To obtain high-yield H2+ ion beam, experimental and theoretical study was carried out on the 2.45 GHz Peking University permanent magnet electron cyclotron resonance ion source (PKU PMECR). With PMECR II*, studies on the size of discharge chamber and the operation pressure were carried out to increase H2+ ion fraction. Beam analysis results prove that the H2+ can reach 40.5% with suitable operation parameters. More details will be presented in this paper.
* Zhizhong Song, Shixiang Peng et al., Rev. Sci. Instrum. 77, 03A305 (2006)
** Author to whom correspondence should be addressed. Electronic mail:
sxpeng@pku.edu.cn.
 
 
MOPME035 Design of a Non-Intercepting Beam Diagnostic Device Using Neutral Beam Fluorescence Method 547
 
  • J. Zhao, J. Chen, J.E. Chen, Z.Y. Guo, S.X. Peng, H.T. Ren, Y. Xu, A.L. Zhang, T. Zhang
    PKU, Beijing, People's Republic of China
  • H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  The forward neutral beam from deflecting magntic field carries some characteristic properties of high intensity particle beams, such as profile, emittance etc. Therefore a reliable measurement of neutral beam fluorescence can be used to develop a fast and non-interceptive beam diagnostic tool. A non-intercepting beam emittance (profile) monitor using neutral beam fluorescence method has being constructed at Peking University. As a performance test, an emttiance of an extracted proton beam from a permanent magnetic electron cyclotron resonance (ECR) ion source was successfully measured. The details of design and results of measurement will be presented in this paper.  
 
MOPWO014 Numerical Methods to the Space Charge Compensation (SCC) Effect of the LEBT Beam 915
 
  • S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, P.N. Lu, Y.T. Luo, H.T. Ren, Z.H. Wang, Y. Xu, T. Zhang, J. Zhao
    PKU, Beijing, People's Republic of China
  • A.L. Zhang
    Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
 
  Numerical simulation as well as experimental researches on space charge compensation for high intensity, low energy ion beam has been done at Peking University (PKU). In this paper we will describe the simulation model proposed at PKU and use it on the PKU ECR single-charged ion source. It consists of a new concept of equivalent density and more consideration of physical process. A series of arithmetical equations is gained through theoretical derivation. Although no numerical solutions have been carried out from our computation, it is foreseeable that the final result will be achieved soon.  
 
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.
 
 
THOAB102 A Pepper-pot Based Device for Diagnostics of the Single-shot Beam 3093
 
  • S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, P.N. Lu, H.T. Ren, Z.H. Wang, Y. Xu, Z.X. Yuan, T. Zhang, J. Zhao
    PKU, Beijing, People's Republic of China
  • A.L. Zhang
    Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
  • J. Zhao
    State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China
 
  Generally the beam emittance can be measured by different Emittance Measurement Units (EMUs), such as the pepper-pot device, the slit-wire type facility and the Allison scanner. However, for a microsecond single-shot ion beam, the pepper-pot device is a suitable choice because of its cut-off single-shot technique without any time-consuming step. A pepper-pot based beam current & profile measurement device, which is a combination of Faraday cup technique and pepper-pot measurement facility, was developed at PKU. It consists of a main Faraday cup with a pepper-pot mask at its bottom, and a Faraday cup array locating 3 mm away from the pepper-pot mask. This device has been tested at the PKU LEBT test bench and the measurement results are consistent with the results acquired by the Allison scanner. By replacing the Faraday cup array with a fluorescent screen and a CCD camera, this device becomes a facility that not only has the ability to measure the total beam current and the beam profile, but also has the capability to measure the beam emittance for CW or pulsed ion beams. Details will be presented in this paper.  
slides icon Slides THOAB102 [5.332 MB]