nlc - the next linear collider project nlc ip layout what’s new? tom markiewicz lc’99, frascati,...
Post on 15-Jan-2016
219 views
TRANSCRIPT
NLC - The Next Linear Collider Project
NLC IP LayoutWhat’s New?
Tom Markiewicz
LC’99, Frascati, Italy
October 1999
Tom Markiewicz
NLC - The Next Linear Collider Project
Detector Reference Modelsfrom US Linear Collider Detector Collaboration
2m2m
Small detector with 6 T Solenoid Large detector with 3T Solenoid
6m6m
1.2 cm2.5 cm
4T
1.2 cm
Tom Markiewicz
NLC - The Next Linear Collider Project
IR Layout Design Philosophy
20 mrad crossing angle and L*(incoming) = 2 m
Maximize transverse space available for incoming and extraction beam optics
Maximize separation between IP and point where debris can scatter
Compact Low Mass Q1 Magnet
Extract beam outside of Q1
Deal with vibration tolerance (x/y = 235 nm/3.9 nm) without dictating detector design
Support Q1 on piezoelectric mover to adjust position
Leave space for active sensor: interferometer or inertial
L*(outgoing) = 6 m
Leave space for incoming beam optics
Conical Mask (M1): Protect detector from backscattered e+e- beam-beam pairs and SR
Minimum Angle set by Detector Solenoid Field choice
M1 tip location and thickness a detector dependent detail
Beam Pipe: r = 1 cm for 1.2 cm VXD inner layer but move away from beam ASAP
Tom Markiewicz
NLC - The Next Linear Collider Project
Small Detector IR DesignKnut Skarpaas VIII and Andy Ringwall
Detector solenoid coil relatively short, so BQ1 BIP
•OK for optics (ask PT for details)
•OK for Q1 Rare Earth Cobalt
Q2 magnets sit on extension of tunnel floor
Extraction line sits on extension of tunnel floor
Q1_SC and Q1_REC sit in cantilevered support tube
•PT trying to design away need for Q1_SC to be superconducting
•Q1_SC is OUTSIDE the detector when doors are closed
•Engineered design of Q1_REC done
•Q1_REC support scheme developed
Tom Markiewicz
NLC - The Next Linear Collider Project
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0 2 4 6 8 10 12
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0 2 4 6 8 10 12
LCD Small Detector with L* =2m CD1 OpticsPlan View
M1
M2Q1 Q1-SC Q2
Q1-EXT
10 mrad
Support Tube
Lum
RF Shield-10 mrad
Tunnel Wall
Beam Pipe
Tom Markiewicz
NLC - The Next Linear Collider Project
IR Layout Details
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 0.5 1 1.5 2 2.5
X (cm)
Y(cm)
Q1
Extraction Beampipe
Maximum Radius of Pair Background
x-y Distribution of Pair e-,e+ at z = 2 m1 TeV, 6 Tesla Field Map
Pairs deposit ~ ½ Watt DC 109 rad/year
Plan View - 6 Tesla Detector
Pair Energy Monitor
Collar
Tom Markiewicz
NLC - The Next Linear Collider Project
Q1: Rare Earth Cobalt (REC) Sm2Co17 or Sm1Co5 Permanent Magnet•Smaller mass works better with active vibration stabilization•Compact: Not much transverse space available, want to send spent beam outside Q1•No fluids•BUT: can REC survive B|| (reduces max. pole tip field) and B (demagnetizes over time)?
•Looks OK: For small detector Bz(2m) < 3 T and Br(2m) < 500 G•Materials study planned•If a SC Shield magnet is needed, would need to rethink entire layout
Q1 SC: SuperConducting•Energy tune-ability, aperture @ 500 GeV•Self-shielded (second coil) (if IN detector)
to not affect the out-going beam•Can we engineer this SC magnet away?
Q2A & Q2B: Iron •Energy tune-ability•Outside detector•Needs to fit in transverse space allowed by crossing angle and extraction line
Q1-EXT: REC Permanent Magnet to minimize space required
Final Doublet Magnet Technology Choices
Q1
SC Solenoid Shield
Reduction in Pole Tip Field ofSm2Co17 in an External FieldFrom To Field1.1% 2.7% 1.5 Tesla8% 21% 4 Tesla20% 62% 6 Tesla
Tom Markiewicz
NLC - The Next Linear Collider Project
LC Small Detector Field Map
0
1
2
3
4
5
6
0 0.5 1 1.5 2 2.5 3 3.5 4
Bz
versus z, NLC IR Solenoid 1
Bz,
T
z, m
Bz, T
0
0.01
0.02
0.03
0.04
0.05
0 0.5 1 1.5 2 2.5 3 3.5 4
Br vs z along beam path, NLC IR Solenoid 1
Br,
T
z, m
Br, T
L* L*
Uniform Current Density 6 Tesla Coil
Tom Markiewicz
NLC - The Next Linear Collider Project
Accommodation for •piezo actuators•sensor systems
•lines of sight for interferometric sensors•space for inertial sensors
•fast feedback electrodes and kickers•beam monitoring and physics detectors•crab cavity•vacuum flanges
Detector access issues:•Doors that open in z
•Is a clam shell geometry (open detector in x or y) possible?•Detector readout electronics and cable plant
Support for weight of masks
Assembly/De-assembly plan
Efficacy of possible support tube spanning the IP
Magnet Space Conflicts
IR Hall Conventional Facilities
Operating modes: e.g. Push-Pull detectors sharing a hall
Engineering Detailing in Progress