Module mounting Ian Wilmut (RAL)

Martin Gibson Martin has been developing the module mounting system at RAL for the last two years – everything we have so far comes from his input. Martin died on Tuesday 20 th August from Oesophageal cancer Module mounting activities will continue at RAL picking up where Martin left off. – We hope we can continue to do as good a job as he always did We are all very sad about this – and are only now starting to realise just how much he knew

I will talk about Stave 250 – Where we stand today (well Monday when I left) – What we had to do to get here Recap on how the module mounting works – Very quick Plans for stave 250 Plans for the long term future – 130nm modules – Pixel disk module mounting Problems we have encountered – What stave producers might try and improve!

Stave 250 Received Repaired Retested Installed in frame Test connected to infrastructure Ready for mounting 5 flat test plates to “flat” stave 3 psudo bowed modules to “flat” stave 2 real bowed sensors to stave Stave 250 (DC-DC)Module mounting

Stave 250 repair Stave 250 was built in the US between Brookhaven and LBL It was packed and shipped form LBL When it was received at RAL it had been “smashed” on one end We have instigated a repair by flooding the core with epoxy (West G-flex 650) The core was then thermally imaged and cycled top see if any damage was evident.

We had some quite big holes to fill!

We drilled holes along the end…

11 12 Which looked a bit like this

We then injected glue through the holes 11 12

Filling of extra holes Small amount of surface flue where the masking allowed a little build up Smaller crack on rear completely filled

It was set up at QMUL and thermally imaged with warm water Graham Beck, QMUL 1 st August

Thermal Cycling (first 5 cycles – next 5 are similar): - about 45 mins/cycle - Red line is thermocouple taped to End of Stave region (CFRP) Graham Beck, QMUL for WP3/5, 29 April Then thermally cycled

10cm interval IR - 3D images (damaged side, before cycling) Graham Beck, QMUL 1 st August

Before/After IR of damaged end Graham Beck, QMUL 1 st August Water bath and ambient are slightly different temperature before and after (try harder in future!) Maximum T rise of surface above ambient ~ 10 degrees (above pipe) - This is constant within a degree along stave length (0.5C asymmetry due to water cooling along length) and wrt before/after cycling.

Module mounting process I have discussed this lots of times before… – Ref Rather than re-cap the whole process in minute detail here is a “cartoon” explanation of what is happening.

And then Returned to RAL Fitted in the frame Frame fettled to fit stave – We need to understand the stave build better (later in talk) Plasma cleaned again Ready for modules

Module mounting system

We have a stave with a camera that can move in x and y X stage Y stage

LASER As the X axis of the stage isn’t very straight we have laser line to correct things X stage Y stage

LASER Into this we insert a stave in a frame (eachstave stays in the frame for the whole build) X stage Y stage

LASER The frame has a series of fecucials that can be found and a co-ordinate system placed with X stage Y stage

Finish sequence….

Gluing down modules

Challenges Up until 2 months ago only Martin had ever glues modules We are trying to learn how best to do it… Lots of photos etc…

Module shape One specific challenge is that the module change shape when attached to the vac chuck. Free shape Shape on chuck

Status of modules on stave 250 To be written as I go into the meeting at LBL

Lessons learned on stave production The edges are not straight – If this is always going to be the case we need to change the handling tooling Glue filets are a problem – photos on next slide We need to pack more robustly We think we now know how to mount modules as well as Martin did.