View
36
Download
2
Category
Preview:
DESCRIPTION
Activities of Accelerator lab, Tsinghua Univ. on ILC-related researches. Presented by Qingzi Xing Accelerator lab, Dep. Engineering Physics, Tsinghua Univ. Nov. 6 th , 2007, IHEP. A preliminary Thomson Scattering X-ray experimental setup - PowerPoint PPT Presentation
Citation preview
Accelerator Lab of Tsinghua University
Activities of Accelerator lab, Tsinghua Univ. on ILC-related
researches
Presented by Qingzi XingAccelerator lab, Dep. Engineering Physics, Tsinghua Univ.
Nov. 6th, 2007, IHEP
Accelerator Lab of Tsinghua University
A preliminary Thomson Scattering X-ray experimental setup
Field tuning and HOMs measurement of the 9-cell ICHIRO copper cavity model
SC Deflecting Cavity for ultra-fast X-ray pulse
2
Accelerator Lab of Tsinghua University
Positron Source (Compton Scheme)
From KURIKI Masao, ILC School 2006
A preliminary Thomson Scattering X-ray experimental setup
Laserwire components
From Marc Ross, ILC School 2007 3
Electron and laser photon interaction: Positron source & beam diagnostics
Accelerator Lab of Tsinghua University
A preliminary Thomson Scattering X-ray experimental setup
Ocilator
DAQ
Linac
Quadrupole
Faraday Cup
B1
CCD CameraComputer
Collimeter & Shielding
Detector
Laser
Triode Electron Gun
YAG or OTR foil
Slit
4
Accelerator Lab of Tsinghua University
The experimental setup scheme
Parameters of Preliminary Thomson
scattering experiments
5
Accelerator Lab of Tsinghua University
The measurement result for X-ray from MCP
MCP(based on flange)
Valve
CF25 Flange
To Pump
Spare
CF50(35) FlangeAbsorption flakes
Thomson scattering X-ray
X-ray Mulitlayer(angle of reflection is about
50mrad)
6 ns
1.7x104/pulse
X-ray photon
6
Accelerator Lab of Tsinghua University
A Proposed Thomson Scattering X-ray Source (Using 60~100MeV Linac)
7
Accelerator Lab of Tsinghua University
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 field flatness is 53.2% before tuning, and 97.2% after tuning with the PI mode freq. of 1298.2 MHz. 8
Accelerator Lab of Tsinghua University
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. 2
(c) Perturbation of cell No. 3
(d) Perturbation of cell No. 4
(e) Perturbation of cell No. 5
9
Accelerator Lab of Tsinghua University
Calculated (Left) and Measured* (Right) dispersion curves of the monopole and dipole modes
* ▲ and indicates the different polarization in the dipole passbands.
10
Accelerator Lab of Tsinghua University
Modef (GHz)
Calculated
f (GHz)
Measured
R/Q① (Ohm/cmn)
Calculated
R/Q① (Ohm/cmn)
MeasuredTM010-9 1.299249 1.298271 1125.75 974.02
TE111-7a 1.715894 1.728774 6.91 2.63
TE111-8a 1.737056 1.752081 3.76 3.49
TM110-5a 1.926031 1.924716 14.20 7.91
TM110-4b 1.939577 1.939012 13.11 1.01TM011-6 2.169293 134.42TM011-7 2.175969 184.35TM111-1 2.448334 30.49TM111-2a 2.454574 2.456481 20.01 7.55
FM and HOM data calculated and measured①: n=0 for monopoles, n=2 for dipoles; a, b indicate polarizations.
2 2
0 00 0 0
1 1 2 2/ [( cos ) ( sin ) ]
2
L L
z zn
z zR Q E dz E dz
b f W
11
Accelerator Lab of Tsinghua University
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 perturbation objects. |E| (Up) and Ez (Down) are mainly measured.
12
Accelerator Lab of Tsinghua University
SC Deflecting Cavity for ultra-fast X-ray pulse• Deflecting Cavity can be used to generate sub-picosecond’s X-ray
pulses. The scheme is shown below.
• Proposed at LBNL, ANL… Collaboration
13
x
RF kick
Crab crossing
From Andrei Seryi, ILC School 2006
Hard X-ray pulses by electron bunch manipulation and x-ray compression
Accelerator Lab of Tsinghua University
2 Cell Cavity design for LBNL
B_peak •Peak magnetic field @ iris
Waveguide damper for LOM and HOM
14
Accelerator Lab of Tsinghua University
0.5 1 1.5 2 2.5 3 3.5 4
x 109
10-3
10-2
10-1
100
101
102
103
f (Hz)
Z 0 ||
(k
)
iris35, end45iris40, end45threshold
0.5 1 1.5 2 2.5 3 3.5 4
x 109
100
101
102
103
104
105
f (Hz)
Z 1
(k
/m
)
2 ca
vitie
s, v
ertic
al
Transverse Impedance
straight wgthresholdwg with step
2 M /m
working mode
mode in wg@bp
TE111
TE121
0.5 1 1.5 2 2.5 3 3.5 4
x 109
100
101
102
103
104
f (Hz)
Z 1
(k
/m
) 2
cav
ities
, hor
izon
tal
Transverse Impedance
TM110
, unwanted
TE111
2 M /m
Storage ring needed to damp the LOM and HOMs
Waveguide for LOM, HOM and unwanted Dipole mode at x-direction
Impedance below threshold
Impedance after Waveguide Damping
Longitudinal Impedance
Transverse Impedancehorizontal vertical
15
Accelerator Lab of Tsinghua University
Holes for “Bead-pull”
MAFIA Measured
f / GHz Q f / GHz Q
1.03065 10462 TM01 1.0300 4440
1.03749 10443 TM01 1.0370 4600
1.50065 12842 TM11 1.4995 5400
1.52719 13418 TM11 1.5262 4400
2.03292 14935 TM21 2.0314 7000
2.03557 15014 TM21 2.0345 6240
Q is lower because of
Surface roughness
Cell assembly
Cold Test on Al model
Parallel wire to make a “bead”
16
Accelerator Lab of Tsinghua University
Cold Test on Al model for Damping
Cavity with/without Waveguide damping
17
Accelerator Lab of Tsinghua University
Bunch Length Measurement by RF Deflecting Cavity
Photo-CathodeRF Gun
Linac Linac QuadrupolesRF Deflecting
Cavity Flag
Photo-CathodeRF Gun
RF DeflectingCavity Flag
18
Accelerator Lab of Tsinghua University
different configurations
19
Accelerator Lab of Tsinghua University
3-Cell Deflecting Cavity Design
20
Accelerator Lab of Tsinghua University
Recommended