Author: Li, D.M.
Paper Title Page
MOPFI046 Transverse RF Kicker Excitation and Longitudinal RF Noise Diffusion for Slow Extraction from SAPT 386
  • L. Ouyang, M. Gu, D.M. Li, Q. Yuan, M.Z. Zhang
    SINAP, Shanghai, People's Republic of China
  Two key techniques used in the slow extraction from synchrotron accelerator: longitudinal RF stochastic noise acceleration, and transverse RF knock out excitation have been studied in this paper. Detailed comparison have revealed the potentials and limits of both methods. For the longitudinal RF stochastic acceleration excitation, the focus has been the phase space compression of particles, which makes the them to hasten around the RF bucket of the cavity, thus to lower the senstivity to ripple. For the transverse RF knock out excitation, the emphasis have been optimal schemes of amplitude modulation and frequency modulation of the RF singals. The optimizations are also used to lower the senstivity of the beam to the ripple and to enhance the uniformity of the extracted beam.  
MOPWA018 CW-type HV Power Supply of 50 Hz and its Application in Accelerator Power Supply 699
  • Z.-F. He, D.M. Li, Y.H. Liu, S.L. Wang, J.-L. Zhang, Y.-T. Zhang
    SINAP, Shanghai, People's Republic of China
  Funding: The Knowledge Innovation Program of Chinese Academy of Sciences
  The high-voltage power supply is an integral part of accelerator technology, as its stable and reliable output is an important guarantee for accelerator properly working. In a number of engineering practice of accelerator design and construction, we tried to use the Cockcroft-Walton (CW) type of power supply driven by 50 Hz and got success. It is of simple structure, low cost, easy maintenance, and high efficiency. This report describes the technical difficulties and the solutions in the CW-type power supply driven by 50 Hz. It also gives an introduction of the latest design of 800 kV/30 mA electron accelerator, which is being assembled at SINAP. Recent work has shown that it is an option to choose 50 Hz driven power system when it is more lenient on the voltage ripple but needed to be as high as possible on the energy conversion efficiency.
MOPWA019 Digital Power Supply Controller Development Based on FPGA 702
  • R.N. Xu, C.L. Guo, D.M. Li, R. Li, S. Tan, W.F. Wu
    SINAP, Shanghai, People's Republic of China
  A digital power supply controller of SSRF (Shanghai Synchrotron Radiation Facility) adops advanced DSP, FPGA and precision ADC as core unit and data acquisition unit. The controller, which is embedded in the power supply case, is composed of two cards, DSP card and ADC card. The controller can communicate with IOC by optical fiber via the Ethernet, Manchester or RS-232 port. The parameters of adjusting power supply can be easily changed to achieve high stability and repeatability. The long-term stability is better than 20ppm. The resolution of current is better than 5ppm. As a replacement of imported PSI controller, the controller is mainly used in middle power supplies in SSRF, and it could accord with all the technical requirements of the facility.  
THPWA021 Studies of Density Distribution and Emittance Measurement for High Current Electronic Beam 3672
  • Q.C. Li, Z.-F. He, J.M. Huang, D.M. Li, Y.-T. Zhang, X.K. Zhu
    SINAP, Shanghai, People's Republic of China
  Beam density distribution and emittance are the important parameters of an accelerator. The accurate emittance measurement has an important reference significance for the design of accelerating tube, and provides a design basis for the aperture size of accelerating tube. This paper introduces a beam measurement method which uses multiwire, can rotate in the horizontal plane and adjust in the Z coordinate. The results of simulation show that this method can accurately measure the beam density distribution and emittance, and the accuracy can meet the requirements of applied accelerator.  
THPWA022 An 800kV 30mA Line-Frequency Cockcroft-Walton Dc Generator Using Gas Insulated Transformer for Radiation Application 3675
  • Y.H. Liu, H.L. Guo, Z.-F. He, D.M. Li, M.X. Li, W.G. Shi, H.J. Su, S.L. Wang, Y.J. Yang, J.L. Zhang, Y.-T. Zhang
    SINAP, Shanghai, People's Republic of China
  The design and construction of a line-frequency 800 kV Cockcroft-Walton DC generator using gas insulated transformers are described, as well as the motive to develop it into radiation application. Several features are underlined, preliminary test results of the prototype presented and some problems encountered discussed.  
THPWA023 Research on Modeling of the High-density Current Electron Gun System Based on T-S Fuzzy Model 3678
  • B. Lv, D.M. Li, H.J. Su
    SINAP, Shanghai, People's Republic of China
  Abstract: The stability of the electron beam is considered as an important performance of industrial electron accelerators. For the beam control system of the accelerator, it is significant to obtain the accurate model of the electron gun system. The paper presents a fuzzy modeling method based on the Takagi-Sugeno (T-S) fuzzy model. A T-S model can be obtained using the system identification algorithms from input-output data. In our approach, fuzzy c-means (FCM) clustering algorithm is applied to identify the model structure. And a hybrid method based on quantum-inspired differential evolution algorithm (QDE) and genetic algorithm (GA) is proposed to learn the parameters of T-S fuzzy model. Experiments on the Box-Jenkins gas furnace data have verified the validity of the modeling approach. The simulation results show that the T-S fuzzy model is very well to describe the electron gun system and reveal its performance.