MICE Collaboration Meeting at Frascati, Jun 26~29, 2005

Diffuser Mounting Design

Stephanie Yang

S Yang, 26-Jun-2005 2

Positional requirement of Diffuser

1046 mm

1224.5 mm

z=0

-5951 mm

End Coil

120 mm

-6011 mm

-6014.8 mm

7.6 mm

-7758.5 mm

Diffuser position (relative to the centre of MICE in stage VI).

Q9

Diffuser

17-Jan-2005

5891 mm

250mm

Iron Shield

Patch panel

163mm

-6173mm

Courtesy of Paul Drumm

S Yang, 26-Jun-2005 4

Clearance envelop for the diffuser assembly approx. 150 mm

Diff

user

env

elop

whe

n fu

lly

with

draw

n

Pat

ch

pa

nel

Tracker solenoid

Iro

n s

hie

ldClearance gap = 250mm

Pat

ch

pa

nel

Tracker solenoid

Iro

n s

hie

ldClearance gap = 250mm

163 mm from flange face

The space constraint & positioning requirement

for the diffuser

95 mm

Diff

user

fully

ext

ende

d

The design as it

wasNow it has

changed!

S Yang, 26-Jun-2005 5

The task

To design a mechanism that allows the insertion and mounting of the lead diffuser into the inner bore of the tracker module without having to disturb the mounting arrangement of the PID components;

The tight space (about 140mm gap) between the fibre tracker patch panel and the Iron shield is such that it makes the mounting operation awkward and unreliable;

This design employs a mechanism that is user friendly and guarantees the positioning of the diffuser to the required tolerance level

Lets look at the design principle of that mechanism

S Yang, 26-Jun-2005 6

Insertion of diffuser assembly caused the main arm to be rotated, thereby extending the arm mechanism

See animation in the next 9 pages on how this works

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The Knife edge flange mounted on the top of the patch panel cover plate

The original arrangement

S Yang, 26-Jun-2005 17

NO NO NO! You are not serious! Nothing can touch my Patch

Panel.

Imperial College

Confirmation was sought from our collaborator on Fibre Tracker…………and…

S Yang, 26-Jun-2005 18

Patch Panel module Drawing received from Geoff Barber in Imperial Collage on 23 rd Jun, 2005

Courtesy of Geoff Barber

S Yang, 26-Jun-2005 19

Adaptive Knife-edge flange mounting on the end plate of the tracker module

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The need to feed the fibres from the fibre tracker out to the patch panel requires extra radial space. As a result, we have to modify the top-hat design to accommodate both the diffuser and the extra room for the fibre feed through.

Radial space needed by the diffuser

Space needed by the fibre

S Yang, 26-Jun-2005 21

One of the solution for fixing the diffuser mounting problem:

S Yang, 26-Jun-2005 22

3D exploded view

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Summary

We believe the diffuser works well. We have made two prototype (a scaled model and a full model) to demonstrate how the mechanism works;

The need to liaise with other component supplier is essential. In the case of the patch panel we are pleased that we have identified the problem at this early stage which saved us having to redesign the diffuser mechanism although minor modification was needed to keep both sides happy;

Further improvement is still possible to ease the handling of the diffuser if and when the lead plate needs replacing