SCT EC Material
Stephen Haywood Rutherford Appleton Lab
SCT Material 2Stephen Haywood Jan 2008
Introduction General End-cap
End-cap contributions from:
Paul Bell, Jason Tarrant, Ian Wilmut
and
Brian Anderson, Jeff Bizzell, Richard Brenner, Tim Brodbeck, Pawel Bruckman, Janet Carter, Colin Dabinett, Katharine Dickinson, Peter Ford, Martin Gibson, Harry Gulliver, Nigel Hessey, John Morris, Koichi Nagai, John Noviss, Val O’Shea, Luis Sospedra, Tony Weidberg, Patrick Werneke
Barrel: Alessandro Tricoli
GeoModel: Pat Ward, Grant Gorfine, Moustapha Thioye
SCT Material 3Stephen Haywood Jan 2008
Guiding PrinciplesTDR: To x-calibrate Ecal and InDet, look at E/p; need to understand X0
at O(2)% of its value.
Specify volumes by mass and effective radiation length × density.
Sometimes G4 volumes need to be shifted to avoid clashes and allow them to be “alignable”.
Try to identify every component Look for objects ≥ 1cm3 or 1 g Material is more important at lower radius – and easier to determine Try to retain reasonable spatial precision, but small objects or those
at large radii smeared Shape is not important (for objects << 1 X0).
Composition is important – factor of 3 variation in X0.
Location of transverse radius important at O(1)% level.
SCT Material 4Stephen Haywood Jan 2008
Web
•Note
•Summary Info
•Summary Plots – Pat Ward
SCT Material 5Stephen Haywood Jan 2008
Methodology Observed sub-detectors being constructed Weighed sets of components where possible
– very complicated spreadsheets, documents & many drawingsE.g. Disk spreadsheet: 10 sheets, some 100 r × 15 c
Extracted masses from CAD
Did not have as much time as would have liked.
Raw Info (Eng) “Model” (AT & SH) G4 Geom Description (PW)
Attempt to weigh SCT in TRT – inconsistent, so ignored.
“Workshop”:
1. Alessandro & Stephen check Pat has correctly implemented Model
2. Alessandro & Stephen explain Model to RAL Engineers
SCT Material 6Stephen Haywood Jan 2008
End-cap6 Regions:
1. Modules – done by Peter Kodys
2. Disks & Services
3. Support Cylinder & Services
4. Support Structures (ITE & Front/Rear Supports)
5. External Radial Services
6. External Cryostat Services & PPF1
Surprises: ITE glue: estimate 0.5 kg, measure 1.2 kg; ITE Assy weighs 6.3 kg RTE glue: estimate 70 g, measure 510 kg; Pad weighs 1.2 kg OTE glue: OTE-A weighs 2.1 kg, OTE-C weighs 3.2 kg
Araldite on Airex hard to control
SCT Material 7Stephen Haywood Jan 2008
End-cap MassComponent Mass (kg)
Modules 24
Disks & Services 33
Support Cylinder, Services & OTE 57
Other Support Structures (ITE, Front & Rear Supports) 23
External Radial Services, including STFT & RCT 41
External Cryostat Services, including CCT’s 47
PPF1’s 35
Total 259
SCT Material 8Stephen Haywood Jan 2008
Checks Some comparisons between measurements & CAD estimates Discuss with Engineers Check spreadsheets on separate occasions – small mistakes found Consistency checks
Component Estimate (g) Measure (g) Diff (%) Comment
RCT Spacers 79 74 7 Fittings added?
RCT 11370 10590 7 Complex Assy
PPF1 Mounting plate 142 139 2 Simple metalwork
Monophase Cooling 193 182 6 Complex pipework with connectors
Disk 3390 (from components)
3440 1.6 Scale Model to give measured mass
SCT Material 9Stephen Haywood Jan 2008
PPF0 in VP1 … thanks Bill
SCT Material 10Stephen Haywood Jan 2008
Model vs G4 Geom DescriptionComparison between expected and implemented total material
0
0.1
0.2
0.3
0.4
0.5
0.6
00.
20.
40.
60.
8 11.
21.
41.
61.
8 22.
22.
42.
62.
8 33.
23.
4
Model (no PPF1)
G4
Integrals agree to 0.5%
X0 vs
Not totally trivial to extract X0
from Model – see next
SCT Material 11Stephen Haywood Jan 2008
SCT Material 12Stephen Haywood Jan 2008
0
10
20
30
40
50
60
70
80
Modules Discs Cylinder Ass Structures Ext Services
Mass
Model
G4
Differences between association of volumes.
X0 not directly proportional to Mass due to
Composition Solid angle
X0 integrals
SCT Material 13Stephen Haywood Jan 2008
Difference between EC-A & EC-CComponent EC-A (kg) EC-C (kg) Half-Diff (%) Comment
Support Cylinder
11.0 10.4 3
OTE adhesive 2.1 3.2 26 Poor quality Airex for EC-C
ITE 6.5 6.1 3 Different adhesive coverage
LMT Cooling Clamp
? ?
Sum 19.56 19.64 0.2
SCT Material 14Stephen Haywood Jan 2008
UncertaintiesSealant: 400 g estimated for STFT; could be wrong by factor of 2-3
Coolant: Vapour fractions uncertain; total estimate 6 kg
Omissions: Some identified recently; too small to be worth effort to change
Hard to estimate numbers. So guess: In Tracking Volume: <5 kg on 140 kg, i.e. <4% Total EC (including PPF1): <10 kg on 260 kg, i.e. <4%
SCT Material 15Stephen Haywood Jan 2008
Model
SCT Material 16Stephen Haywood Jan 2008
SCT Material 17Stephen Haywood Jan 2008
6 spreadsheets
~10 Sheets
1-3 Volumes/sheet
•Mass
•Composition
•Numbers
•Dimensions
•Location
SCT Material 18Stephen Haywood Jan 2008
Pat’s Plots
SCT Material 19Stephen Haywood Jan 2008
Modules / Disks / Cylinder Services/ Ext Services
SCT Material 20Stephen Haywood Jan 2008
Fixed Vtx / Smeared Vtx / Scan / z Scan
SCT Material 21Stephen Haywood Jan 2008
Modules / Cylinder Services
SCT Material 22Stephen Haywood Jan 2008
CSC-03 vs TDR
It’s got worse !
Difficult/tedious to understand changes.
It is what it is.
Only issue is for future: what tends to get underestimated?
Difference between CSC-03 and ID TDR
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 0.5 1 1.5 2 2.5 3
Eta
Del
ta X
0
Pix
SCT
TRT
Ext Services
Sum
SCT Material 23Stephen Haywood Jan 2008
Conclusions
Believe Model is a good description of reality G4 Geom Description is a faithful representation of the Model Description good to a few percent All effort in vain if Pixels have not done at least as good a job We have not looked at SCT (B+EC) Services beyond PPF1
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