SCT EC Material

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


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.


Web

•Note

•Summary Info

•Summary Plots – Pat Ward


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


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


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


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


PPF0 in VP1 … thanks Bill


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


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


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


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%


Model


6 spreadsheets

~10 Sheets

1-3 Volumes/sheet

•Mass

•Composition

•Numbers

•Dimensions

•Location


Pat’s Plots


Modules / Disks / Cylinder Services/ Ext Services


Fixed Vtx / Smeared Vtx / Scan / z Scan


Modules / Cylinder Services


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


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

SCT EC Material

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