21/11/2002 Muon Meeting

Burkhard Schmidt

Envelopes and ClearancesOutline:• Definitions• General situation

• Request of Calorimeter group

21/11/2002 Muon Meeting

Burkhard Schmidt

Envelopes and ClearancesOutline:• Definitions• General situation

• Request of Calorimeter group

Definitions: (provided by our TC)• Envelope of a detector consists of:

+ Mechanical dimensions+ Mechanical tolerances, piled up if composite+ Possible operational deformations (e.g.: bending, overpressure)

• Clearance: – Space between envelopes, this is "No-man's land" governed by

the Technical Coordination

-> These two issues were mixed up to now !

21/11/2002 Muon Meeting

Burkhard Schmidt

Envelopes and ClearancesGeneral situation:• Tight, in particular around the calorimeters

(only 1cm between PS, ECAL, HCAL and M2)

Proposal: (of our TC)• The only way to get more space is to shift the

detector downstream by up to 10cm (maximum)-> The group to whom the space downstream the

experiment is allocated (beam pipe) agrees-> What about us? Also for us the situation is tight!

21/11/2002 Muon Meeting

Burkhard Schmidt

Envelopes and Clearances

Proposal (ctd.): (of our TC)

   Delta-z z-min z-max z-mean Shift

(RICH2) 11900Clearance 20 11900 11920M1 360 11920 12280 12100 (- 5mm)Clearance 20 12280 12300Calorimeter 12300 15050Clearance 40 15050 15090M2 360 15090 15450 15270 (+ 70mm)Clearance 10 15450 15460MF1 820 15460 16280Clearance 10 16280 16290M3 360 16290 16650 16470 (+ 70mm)Clearance 10 16650 16660MF2 820 16660 17480Clearance 10 17480 17490M4 360 17490 17850 17670 (+ 70mm)Clearance 10 17850 17860MF3 820 17860 18680Clearance 10 18680 18690M5 360 18690 19050 18870 (+ 70mm)Clearance 30 19050 19080MF4 820 19080 19900

21/11/2002 Muon Meeting

Burkhard Schmidt

Envelopes and ClearancesProposal (ctd.):

• In order to adjust to the new mean station positions in the smoothest way, we should keep the pad dimensions of M3 essentially unchanged (6.75mm x 27mm in M3R1), which means negligible differences to the M2, M4 and M5 chamber sizes (<1mm).

• For M1 the R3/R4 chamber size would be in x=7.9mm less and in y=1.6mm.

• Concerning the muon filter, an envelope of 82cm seems indicated, given the present ideas on how to build up the walls.

• We have to be sure that we can make it with a chamber envelope of 36cm ! It leaves about 76mm for each chamber (including tolerances and fixation 79mm).

21/11/2002 Muon Meeting

Burkhard Schmidt

Request to change envelope at some points for M1

21/11/2002 Muon Meeting

Burkhard Schmidt

Request to change envelope at some points for M1

The SPD/PS people would like to get additional 5cm in zof M1 at |y|>335cm to avoid complications with the MaPMT and the FE-cards.

As it is outside the muon chamber area (sensitive area ends at y=320cm), we have only the support structure there.

I have the impression that we can accept this request.

Comments ?