THB5 —  Working Group B - Session 5   (07-Jul-16   14:00—15:40)
Chair: M. Ikegami, FRIB, East Lansing, Michigan, USA
Paper Title Page
THPM1Y01
 Beam Dynamics Design of CIADS superconducting linac  
 
  • S.H. Liu, W.L. Chen, Y. He, H. Jia, Y. Tao, Z.J. Wang
    IMP/CAS, Lanzhou, People's Republic of China
  
  Funding: Chinese National Natural Science Foundation：11525523 & XDA03020202
Chinese government has approved the CIADS project, which aims to demonstrate the nuclear waste transmutation technology. The CIADS driver accelerator is designed to be a 600MeV, 10mA CW operation superconducting linac. The main issue of such high power large-scale facility is the construction cost and beam loss control. For superconducting linac, the main cost is spent on the superconducting cavity and RF amplifier system. The improvement of acceleration efficiency of cavity and utilization of RF amplifiers will be useful for the cost saving. The other beam physics issues including lattice design, error simulation and adapted compensation strategy are also studied. In the talk, the cost optimization as well as beam physics considerations will be presented. 		 
slides icon Slides THPM1Y01 [2.791 MB]  
Export • reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPM2Y01
 Instability of CW RFQ With High Beam Loading  
 
  • R. Huang, Y. He, H.W. Zhao
    IMP/CAS, Lanzhou, People's Republic of China
  
  Funding: The National Natural Science Fund 91426303 and 11525523.
The frequency detuning as large as 10 kHz observed on the RFQ of the Injector II of the CIADS when the beam passed by couldn’t be explained by the beam loading theory based on the equivalent circuit analysis, which is a mainstream theory being widely used in the analysis of beam loading nowadays. By introducing the concept of beam-cavity system, together with the impedance model of the beam, the beam induced detuning of the beam-cavity system was proved to be amount to the optimum detuning of the cavity under the given beam condition in a very straightforward way and the problem was therefore converted to the calculation of the optimum detuning of the RFQ. With the introduction of the new notions of effective synchronous phase and RF phase, the existing beam loading theory is extended to the analysis of the more complex accelerating structures, such as RFQ, which has many accelerating cells and with different synchronous phase in each cell, along with more than one dominant mode coexisting in the cavity. The numerical result obtained from the extended beam loading theory was well agreed with the experiment result mentioned at the beginning. 		 
slides icon Slides THPM2Y01 [0.898 MB]  
Export • reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPM3Y01
 Space Charge Resonances in Linacs  
 
  • D.C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  
  Space charge driven resonances in proton linacs have long been recognised as possible sources of emittance growth and halo development, with potentially severe consequences for beam quality and transmission rates. With increasing demand for high intensity, high power beams, understanding and quantifying these effects has become an essential step in any accelerator design. In this paper we briefly review the current resonance models, we analyse the design approach taken in several modern machines and we highlight the latest experimental efforts undertaken to validate theoretical models and code predictions.  
slides icon Slides THPM3Y01 [2.881 MB]  
Export • reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)