1、Activities of Accelerator lab, Tsinghua Univ. on ILC-related researches,Presented by Qingzi Xing Accelerator lab, Dep. Engineering Physics, Tsinghua Univ. Nov. 6th, 2007, IHEP,A preliminary Thomson Scattering X-ray experimental setupField tuning and HOMs measurement of the 9-cell ICHIRO copper cavit
2、y modelSC Deflecting Cavity for ultra-fast X-ray pulse,2,Positron Source (Compton Scheme)From KURIKI Masao, ILC School 2006,A preliminary Thomson Scattering X-ray experimental setup,Laserwire componentsFrom Marc Ross, ILC School 2007,3,Electron and laser photon interaction: Positron source & beam di
3、agnostics,A preliminary Thomson Scattering X-ray experimental setup,4,The experimental setup scheme,Parameters of Preliminary Thomsonscattering experiments,5,The measurement result for X-ray from MCP,6 ns 1.7x104/pulse X-ray photon,6,A Proposed Thomson Scattering X-ray Source (Using 60100MeV Linac),
4、7,9-cell superconducting ICHIRO copper cavity model provided by KEK.,Field flatness measurement system of the ICHIRO cavity.,Field tuning and HOMs measurement OF the 9-cell ICHIRO copper cavity model,Relative axial electric field of the TM010_PI mode obtained from the bead-pull measurement. The fiel
5、d flatness is 53.2% before tuning, and 97.2% after tuning with the PI mode freq. of 1298.2 MHz.,8,The change of the field and the spectrum due to the perturbation of individual cells, based on the analysis of the equivalent circuit model .,(a) Perturbation of cell No. 1,(b) Perturbation of cell No.
6、2,(c) Perturbation of cell No. 3,(d) Perturbation of cell No. 4,(e) Perturbation of cell No. 5,9,Calculated (Left) and Measured* (Right) dispersion curves of the monopole and dipole modes * and indicates the different polarization in the dipole passbands.,10,FM and HOM data calculated and measured :
7、 n=0 for monopoles, n=2 for dipoles; a, b indicate polarizations.,11,Relative frequency shift of the TE111_PI mode 1.5cm off the axis obtained from the bead-pull measurement using a dielectric (Left) needle ( d = 1.4 mm, l = 16.6 mm ) and a metal (Right) needle ( d = 0.31 mm , l = 20 mm ) as perturb
8、ation objects. |E| (Up) and Ez (Down) are mainly measured.,12,SC Deflecting Cavity for ultra-fast X-ray pulse,Deflecting Cavity can be used to generate sub-picoseconds X-ray pulses. The scheme is shown below. Proposed at LBNL, ANL Collaboration,13,Crab crossingFrom Andrei Seryi, ILC School 2006,Hard
9、 X-ray pulses by electron bunch manipulation and x-ray compression,2 Cell Cavity design for LBNL,B_peak,Peak magnetic field iris,Waveguide damper for LOM and HOM,14,Storage ring needed to damp the LOM and HOMs Waveguide for LOM, HOM and unwanted Dipole mode at x-direction Impedance below threshold,I
10、mpedance after Waveguide Damping,Longitudinal Impedance,Transverse Impedance,horizontal,vertical,15,Holes for “Bead-pull”,Q is lower because of Surface roughness Cell assembly,Cold Test on Al model,Parallel wire to make a “bead”,16,Cold Test on Al model for Damping,Cavity with/without Waveguide damping,17,Bunch Length Measurement by RF Deflecting Cavity,18,different configurations,19,3-Cell Deflecting Cavity Design,20,Thanks for your attention!,
