# Presentation: 270962

## Si Upgrade - Mechanics

-  Review of Hytec study
-  Mounting scheme
-  Services

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## Hytec - material selection

- Material for the support structure was selected on
- the basis of:

-  High radiation length
-  Low density
-  High stiffness
-  Availability

- Materials considered:           Cons:

- Availability, thermal expansion

- Strength, thermal expansion, density, RL

-  GFRP
-  Beryllium
-  Carbon-Carbon
-  Aluminum

- Usually used for thermal apps.

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## material - cont’d

- GFRP - graphite fiber - epoxy composite:
-              which fiber?
-              Choose one based on cost, availability.
-              M55J

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## strength analysis

- Different structures were tried....

- ... and analyzed for strength.
- Dumbbell shapes have low
- bending strength.
-          Choose single-barrel shape.

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## build in sections

- Atlas Si detector

- 3 sections, bolted together

- Endcap frame

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## cooling

- Based on the experiences with the Alice and Atlas
- cooling designs

-  Negative pressure system
-  Water-methanol
-  CFC evaporative
-  CFC single-phase

- And the lower total load (~2.2kW), and the lower
- power density (0.1-0.7 W/cm  )
-          choose single-phase CFC

- Run C6F14 or C5F12
- at modest overpressure

- 2

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## cooling - cont’d

- Endcaps are cooled
- by tubes embedded
- in the support
- sandwich.

- Barrels are cooled
- with carbon-Carbon
- thermal plane with
- ‘Omega’ structure.

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## mounting scheme

- TPC/HBD mounts
- from the top CM yoke.
- The Silicon detector
- comes in from the
- bottom, much like
- the MVD does now.
- Translate or clamshell?

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## side view - services

- Power, cooling and
- signal services are
- brought in at both ends,
- using the entire perimeter.

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## services - power

- Power: at 0.1W/cm   for 1.8V technology

-   1       10.5       32                18
-   2       14.1       60                33
-   3       18.0      100               56
-   4       18.0      100               56

- Total:  163A

- If the voltage drop over 100’ is 1%, then this can
- be delivered via copper cable if the area is
- 28cm  .
- Total for barrel + 2 endcaps: 190 cm   of copper.

- Disk      r      power(W)     Current(A)

- 2

- 2

- 2

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## services - cooling

- Count tubes on various
- drawings.

- 1/2 of one endcap

- 128 tubes for 2 endcaps,
- bundle 9/cm
-        14 cm   total

- Assume a similar area for the barrel
- [ air cooling -> more area ]

- 2

- 2

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## services - fibers

- Assume 1 fiber per ladder for the barrel,
- 2 per ladder for the endcaps:
- Barrel    86 cables   =  16.9 cm
- Endcaps  64/end      = 12.5 cm
- Total for fibers: 42 cm

- 2

- 2

- 2

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## services - how much space

-                                             total area     dz per end
- From ‘first principles’           352 cm        1.4cm
- Current MVD:
-     ~50% of perimeter           940 cm        2.5cm
- Rule-of-thumb from
- Veljko Radeka: 12% of
- Silicon area (Atlas)              1444 cm       5.7cm

- Assume that services (power, air, liquid coolant,
- copper and fiber are brought in on both ends, using
- the entire perimeter at r=20cm.

- 2

- 2

- 2

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## to be studied

-  Power distribution - local  voltage   conversion,mass issues
-  Cooling - can some be done with air?
-  Keep an eye on integration

- For the next round, technology choices
- need to be pinned down

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## future

- Our progress-to-manpower ratio compares favorably with industry standard.

- Our progress-to-funding
- ratio compares favorably with
- industry standards

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## services

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke

## -

- .     Si upgrade workshop, 9 June 2003 - Hubert van Hecke