AMS tracker hardware status(mechanics and cabling)

Divic RAPIN, UniGe AMS splinter tracker , Septidi 7 Brumaire 217 (october 28, 2008)

• off-line operations• preparation for integration

Franck CadouxEric Perrin*Divic Rapin

Florian MasciocchiPhilippe BouvierJavier MesaMaarten WeberManfred Willenbrock*

With the help of S.Lucidi (Perugia) for paper work (QA)* Retirement approaching

Université de Genève

University of Geneva staff involved:

NIKHEF and NLR staff involved:Bart Verlaat, Erno …, Johannes Van Es, Aswin Pauw

Ladder repair (test with mobile station)

• Non working ladders were:– L15AP098 (read-out:600 oct:8 pwg:1 TDR:1B) Layer:8, slot:7M (---)

bad K cable recoverable repairing of cable failed Spare S-type cable was used – L12AJ019 (read-out:309 oct:3 pwg:1 TDR:3B) Layer:4, slot:6P (+-+) K

cable disconnected recoverable with front shell opening

K flight cable connector of L15AP098 DR. july 18, 2008

Pin 2 Guard ring

Line 5 (H1)

6 ohm 1.5 ohm

1.5 ohm

Pin 7 (H1)

• Test of K flight cable showed interruption on pin 7 of connector of TDR side.

• Surgery to access connections on patch panel for better diagnostic.

• Contact was re-established (by chance). Poor contact through the Airborne connector.

• Airborne connector faulty ?? Or cold soldering ???

• This problem occurred already with another cable.

Apparent repairing by resoldering pin 7, but failure showed again after reinstalling sleeve

Change cable (s-type)

Ladder L12AJ019 Layer:4 Col:6P (+X –Y +Z) octant:3 pwgrp:1 TDR:3B Read-out: 309 ?

Pictures taken may 8, 2007. After tests. Just before closing last shell

DSCN0356.JPG

DSCN0353.JPGConnection hidden during most of the time by supporting bars.Tests were OK

Fixation of connectors with Kapton tape

OK

U

Access by

outer side

only !

Front shells were opened

Special tools were designed to hold the scotch tape (with vacuum)

Example of new fixation on –X side

Operations on evaporators (cooling loops)

• Change (weld) new connectors

• Modify the pigtails to solve the interferences with LTOF

• High pressure and leak tests ( 200? bars)

• Mounting on external planes + checks

• Cleaning (this week)

• Mounting on inner tracker (to be done)

AMS TRACKER ADP Annex 1

Modification of the top evaporator to provide more clearances with the tracker cables

Fig. 1 below is showing the interference between one of the copper blocks of the top evaporator with the tracker cables in the vicinity of the Star Tracker support

Copper block before and afterthe modification on ladderPositions 10 M and 10P.

Work done by PhB/ EP 16/7

Incompatibilities between locations of LTOF patch panel and pigtails of the tracker lower cooling pipes and collision.

Need to modify the lower cooling loops by replacing the last pigtails by a simple S.

AMS TRACKER ADP Annexe 2

Modification of one evaporator loop to solve interference with Lower ToF (LToF)

6mm down

Twisting in this area

New connectors welding, pigtails suppression, tests

Bart Verlaat

Erno

Cleaning (this week) • Flush with CO2

• Rinse with IPA

• Flush with CO2Aswin Pauw NLR

Cleaning (this week)

Mount outer evaporators on planes + check support geometry

modificationsTwo types of fixation:• Plane only: on thermal bars + plane• Shared: brackets on conical flange + plane

Fixation on thermal bar (upper part on plane not shown)

Spring coupling

Thermal bridge

Screw securing: helicoils + glue

ChoTherm

Six damaged helicoils or threads were repaired

Riveting and gluing of the upper parts of fixations

Two pins to secure cable connectors

Five different sizes ! (clearance from 0 to 1 mm)

Trial assembly of the whole bracketery supporting the

evaporators. Design & fabrication of new

and missing brackets

• New brackets• Jigs to simulate the fixation of the lower part of brackets to conical flange • Check if it fits

Maarten Weber

… in order to avoid bad

surprises at final

integration..

Supporting brackets for evaporator connectors

• New loop connectors need a better fixation (magnetic force twice ~ 5 N )

Tracker crate balconies

Lower parts installed with controlled torques

ATS exists

Remaining off-line operations

(in clean room)

• Evaporators (cooling loops)- Cleaning (in progress)

- Outer planes- Terminate test and installation of bracketry (in progress)- Install connectors securing pins (plane 1 done)

- Inner Tracker- Install upper inner cooling loop- Glue and prolongate DS thermal sensor chain- Install evaporators supporting brackets on conical flange- Install thermocouples for TVT tests (locations to be defined)

Missing procurements

- Mylar patches on M10 nuts (ship to US)- Structural screws (NASA)- Shims for tracker feet. (clarify situation)

Cold Vacuum Case Installation

• No solutions are seen if we want no stress on feet during mission. (impossible to mount the feet under stress)

• If one accept stress on the feet during mission, mounting the feet with pumped VC can be considered.

Opinion :

Preparation of final integration

• Update of integration procedures (ATS, S. Lucidi, FC, EP, DR) taking into account what we have learned in pre-integration and the limitations imposed by the real vacuum case:

- Limitation of RAS rotation

- Field mapping / Need for special protection

- Cryogenic services to VC

- Final cabling