g.barber: sci-fi mechanical design - tracker meeting cern 29 march 20041 latest thoughts on...

1G.Barber: Sci-Fi Mechanical Design - Tracker Meeting Cern 29 March 2004

Latest thoughts on Mechanical Design

Contents:-

Revised Fibre Pitch

Fibre Optic Connectors and Light Guide Map

Station Fabrication

Other Work


Revised Fibre Pitch

• 639 channels / station: 213/view– Pitch: 318 (mm) / (213*7) * 2 => 427 microns pitch

• 5*128 channel D0 connectors/station (per tracker)– 5 stations => 25 D0 connectors => require 4

cassettes

• 2 cassettes per cryostat: one on either side– 16 D0 connectors worth/cryostat


Mechanical Layout of Sci-Fi

Modified Patch Panel

This is a Modified Patch Panel, it allows the fibres to come out in the lower half and fall to both sides.

It is designed to fit in the given ‘Z’ of 3cm and to allow enough surface area to accommodate the correct number of connectors it wraps back over the flange of the cryostat. I have been looking at the bulkhead connectors in order to make them easier to seal against vacuum and will give a greater packing density. The design you will see later is designed to be 128 way (one to one with the vlpc connector) and use 5 per station.


Ideas for the Fibre Optic Connectors

In conjunction with the patch panel I think we need to take another look at how we take the light guides through the vacuum and make a reliable seal. One way to hopefully cut down on leaks is to have fewer connectors another way is to make the sealing face circular. This is a first attempt at such a connector and was offered for comment.


Ideas for the Fibre Optic Connectors

This came from comments received. In conjunction with the patch panel I took another look at how we take the light guides through the vacuum and make a reliable seal. This is what came from the comments made during the workshop at FermilabIt has 128 channels and so is a match for a VLPC cassette. All the routing of channels is done inside the chamber and to facilitate this the connector flange and the connectors are to be changed.


Re-designed Station Connector - 22 Way

The previous connector had 18

channels it was not possible to use this in the current scheme so it will be changed to

22 channels


Preliminary Connector Map

View ‘X’ 213 Channels

View ‘W’ 213 Channels View ‘V’ 213 Channels

0-21

22-42

43-62

85-10663-84 107-128

191-212

129-150

151-170

171-190

20 20

22 22

21 20

22 22 22 22

0-21

22

22-43

44-65

66-85

22

22

19

86-104

105-126

127-148

149-170

171-192

193-212

20

22

22

22

20

22

20

2222

22

22

19

20

22

22

22

0-1920-41

42-63

64-85

86-107

108-127

128-146

147-168

169-190

191-212


New Station Profile

This new station is designed with the latest connector

layout and hopefully a one piece construction.

It also has more finger room around the

connectors to allow fitting.


Layout of Sci-Fi Stations

This is a layout of the 5 stations, it does not yet have the correct pitch spacing to optimise the performance. For this we need to know the centre and length of the ‘good’ magnetic field. It may also have slight mechanical constraints arising from assembly difficulties if the pitch is to close. This may need to be studied further with a model.


Mechanical Layout of Sci-Fi

The tracker sitting in the ‘good’ field of the magnet.


Possible fixation of Sci-Fi in Bore.

The red ring is fixed to the bore of the cryostat. It has reamed holes that

are matched to the assembly dowels of the tracker, after they are located

in this ring a second ring can be pushed in from the

rear and again dowels locate in reamed holes. This is

only a 1st idea and I am sure there are other ways to locate the tracker.


Other Work - Cryo-Station

We are also looking into the feasibility of building a VLPC cryogenic test rig to carry out prototyping and have been given some very good advice and offers of help from experts here at Fermilab and also at Ral. (Very) Rough Layout

g.barber: sci-fi mechanical design - tracker meeting cern 29 march 20041 latest thoughts on...

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