Keyword: superconductivity
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MOPWA008 Power Supply of the Pulse Steering Magnet for Changing the Painting Area between the MLF and the MR at J-PARC 3 GeV RCS power-supply, injection, proton, controls 681
 
  • T. Takayanagi, N. Hayashi, K. Horino, M. Kinsho, T. Togashi, T. Ueno, Y. Watanabe
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
 
  The power supply of the pulse steering magnet (PSTR) has been produced. The PSTR of the 3-GeV RCS (Rapid Cycling Synchrotron) in the J-PARC (Japan Proton Accelerator Research Complex) aims at changing the painting area in a pulse-to-pulse mode at 25Hz between the MLF (Material and Life science Experimental Facility) and the MR (50-GeV Main Ring synchrotron) at J-PARC. The power supply has the equipment used to excite the pulse current and the direct current (DC) to correspond to two modes that the paint injection for beam users and the central injection for beam commissioning. In case of the paint injection, the power supply excites the current from 40 A to 450 A in pulse mode, which has the capability to switch from positive to negative polarity. The pulse current has been performed with good accuracy whose deviation to a setting current becomes to be less than ± 0.2 %. In case of the central injection, the power supply excites the current from 1000 A to 3000A in DC mode, which has been realized output current deviation below ± 0.01 %. This paper summarizes the design parameters and the experimental results of the power supply.  
 
WEPWA035 Design of a Superconducting Undulator Magnet Prototype for SSRF undulator, synchrotron, electron, storage-ring 2205
 
  • Z.C. Zhang, J. Cui, J.Y. Jiang, M. Li, W. Li, J.P. Xu, J.J. Xu, J.F. Yu
    SINAP, Shanghai, People's Republic of China
 
  Funding: Project 11275254 supported by National Natural Science Foundation of China.
A 0.65 T NbTi superconducting undulator magnet prototype with a period length of 16 mm and a period number of 5 for SSRF is designed. The magnetic field simulation shows that it is possible to obtain a peak field of 0.6 T on the beam axis at a magnetic gap of 9 mm, with a current density of 800A/mm2 in the superconducting coils. Two coil formers are machined from SAE1018 stainless steel and coated with TiO2 for insulation. The dimension of the grooves of the coil windings in the coil formers is 5 mm x 10 mm. Formvar insulated NbTi superconducting wires with a diameter of 0.6 mm are used for the 128 turn coils per core groove. A five periods core of NbTi superconducting magnet is machined from SAE1018 stainless steel and winded with copper wires.
 
 
WEPWO028 10×10mm2 MgB2 Film Fabricated by HPCVD as a Candidate Material for SRF Cavit cavity, SRF, radio-frequency, heavy-ion 2375
 
  • F. He, K.X. Liu, Z. Ni, D. Xie
    PKU, Beijing, People's Republic of China
  • Q. Feng
    Peking University, Beijing, People's Republic of China
 
  Magnesium diboride (MgB2) is one of candidate material for superconducting radio frequency cavities because of its good features: high transition temperature of ~39K and absence of weak links between grains which prevents other high-Tc superconducting materials, such as YBCO. Previous study of MgB2 are mainly focused on the films’ superconducting properties which are fabricated on Al2O3, SiC or some metal substrates with small scale less than 10×10 mm2. In this work we explore a technique to deposit clean and large-scale MgB2 films on Mo substrate, which is expected to provide a probable way to fabricate MgB2 thin-film cavities.. The measurement results show that its superconducting properties and mechanical behaviors are as good as those fabricated on small-scale metal substrates.  
 
WEPWO067 Conditions for the Existence of 1- and 2-point Multipactor in SRF Cavities cavity, electron, simulation, multipactoring 2456
 
  • V.D. Shemelin
    CLASSE, Ithaca, New York, USA
 
  Funding: NSF award DMR-0807731
One- and two-point multipactor (MP) in RF cavities are well-known phenomena. However, conditions when this or the other type of discharge develops were not clearly defined up to now. Here, an explicit description of these two types of the MP is presented, geometrical parameters, or figures of merit, responsible for initiation of the MP defined, and areas of their existence delineated. Small sizes of trajectories in the MP require a very precise calculation of fields for simulations. On the other hand, due to these small sizes, fields can be presented as the Taylor expansions and trajectories can be found solving ordinary differential equations of motion. Conditions of motion stability and influence of the Miller force are also accounted.