JLC Collimation System Design

velodromeryeΠολεοδομικά Έργα

15 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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T.Ohgaki, ISG9, Dec 10-13, 2002 1
JLC Collimation System Design
T.Ohgaki (KEK)
JLC FFIR/BDSIM Collaboration
1. JLC Collimation System
2. Synchrotron Radiation, Electron Loss
3. Muon Attenuators
4. Summary
T.Ohgaki, ISG9, Dec 10-13, 2002 2
JLC Collimation and Final Focus
Based on NLC Collimation system + Pantaleo’FF
Full crossing angle 6mrad for changing the angle
of energy collimation
T.Ohgaki, ISG9, Dec 10-13, 2002 3
JLC Beam Parameters
Center of mass energy 500 GeV
Number of particle per bunch 0.75x10
10
Number of bunches per train 192
Repetition frequency 120 Hz
Horizontal normalized emittance 3.6x10
-6
m rad
Vertical normalized emittance 4.0x10
-8
mrad
Horizontal beta function in IP 8x10
-3
m
Vertical beta function in IP 1.1x10
-4
m
Horizontal beam size in IP 243 nm
Vertical beam size in IP 3 nm
Horizontal angle in IP 30 
rad
Vertical angle in IP 27 rad
T.Ohgaki, ISG9, Dec 10-13, 2002 4
Collimation Depth &
Energy Collimation
Collimation Depth Criteria:
No photon hit R > 1cm at z = 350cm
x’< 13 x 30.3 rad y’< 43 x 27.3 rad
(13
x
, 43
y
)
Energy Collimation Momentum acceptance
|p/p| < 0.015
T.Ohgaki, ISG9, Dec 10-13, 2002 5
Synchrotron Radiation
s=-3.51s=0
Core, p/p 0.3%, macro 10000 (T-ratio: 1)
total number of photons 342752 (9.096 MeV) (Collimation+FF)
number of photons at IP 10890 (loss 331862)
x (m)
x (m)
y (m)
y (m)
IP front of QD
T.Ohgaki, ISG9, Dec 10-13, 2002 6
Synchrotron Radiation
s=0 s=-3.51
Flat, 13
x
43
y
, p/p 3%, macro 10000 (T-ratio: 0.3346)
total number of photons 217488 (19.39 MeV) (Collimation+FF)
number of photons at IP 12208 (loss 205280)
x (m)
x (m)
y (m)
y (m)
front of QD
IP
T.Ohgaki, ISG9, Dec 10-13, 2002 7
Synchrotron Radiation
Flat, 13
x
43
y
, p/p 3%
s=-3.51
Core, p/p 0.3%
s=-3.51
QD MagnetQD Magnet
x (m)x (m)
y (m)
y (m)
T.Ohgaki, ISG9, Dec 10-13, 2002 8
Muon backgrounds
MUCARLO (Namito version)
4 Muon attenuators 37mx2,45m,70m
(option 15m,20m)
Electron beam: 250GeV
Muon generation point: Spoiler,Absorber
IP
Drift space
77m
48m37m20m 25m 37m
T.Ohgaki, ISG9, Dec 10-13, 2002 9
JLC Muon Attenuator
T.Ohgaki, ISG9, Dec 10-13, 2002 10
Magnetic field of muon attenuators
T.Ohgaki, ISG9, Dec 10-13, 2002 11
Radius and sands of muon attenuators
400 600 800 1000 1200 1400 1600
10
4
10
5
10
6
10
7


e/mu
Distance from IP (m)
inner 11cm & outer 31cm + sands
inner 18cm & outer 78cm + sands
All sands
T.Ohgaki, ISG9, Dec 10-13, 2002 12
400 600 800 1000 1200 1400 1600
10
5
10
6
10
7
10
8
10
9


e/mu
Distance from IP (m)
10kG large radius & sands
10kG large radius & sands
& 2 short attnuators
Short muon attenuators
T.Ohgaki, ISG9, Dec 10-13, 2002 13
Kuroda’s Collimation + FF
Gy (m)
Gx (m)
JLC Collimation + FF
Crossing 3mrad
Beam Line: 1434m
Big Bend 5.5mrad
JLC Collimation + Final Focus
Gx (m)
Gy (m)
Crossing 3mrad
Beam Line: 2099m
Muon attenuator
T.Ohgaki, ISG9, Dec 10-13, 2002 14
Summary
• Based on NLC collimation system + Pantaleo’FF, we
have studied JLC collimation system by SAD code.
• We have estimated the performance of muon
attenuators in this collimation system by
MUCARLO.
• Plan to make new collimation and final focus for
JLC