Status of the Focus Coil Magnet Procurement

Tom BradshawJohn CobbWing LauMatt Hills

MICE Collaboration Meeting25th June 2012

Elwyn BaynhamMike CourtholdVictoria BaylissVictoria BlackmoreJason Tarrant etc...

Talk will cover: Recent progress at TESLA, Configuration and Schedule

Introduction

Recent Progress and Status

•Radiation shields fitted•Cold mass installed •Cold mass sensor wiring complete•Supports tensioned•Alignment of cold mass completed

Alignment of Cold MassPicture shows the space for the installation of the force transducers for accurate tensioning of the straps.We will monitor these during cool-down – the straps will contract by ~1.26mm

Dummy force transducer shown in position

Jig for installing force transducer

Pre-stress of suspension

Strap 1 0.51Mid link 0.05Strap 2 0.64OVC link 0.06

Reduction in force due to OVC and foot deformation of 0.17mm

Getting ~200kN from stress on cooldown which means that only a minimum room temperature pre-stress is required. This will be monitored during cool-down.

Alignment of Cold MassWing and Jason witnessed the alignment and strap tensioning on the 18th.Cold mass accurately centred Worryingly, the position of the flange hole centres is +/- 0.7mm on best fit pitch circle diameter which is out of tolerance. Best guess is that stress relieving of the OVC over time has caused this – we are investigating.Survey report is available.We are looking into either over- drilling on  the existing bellow flange holes to match the surveyed hole positions on the OVC, or create a new set of holes at half pitch to the existing holes. In other words, the bellow flange will simply have holes to mate the two adjacent modules whatever their hole positions are.

The Helium side is aligned to within 128 microns and -87 microns in the x and y coordinates respectively and the Hydrogen side is aligned to -113 and 67 microns. The required tolerance is ±250 microns.

Recent Progress and Status

Wiring showing the tails exiting the cold mass

Odds and Ends

Poorly performing Cryomech cooler has been returned from US – second one now has to be shipped back.Control and instrumentation is all now available and will be shipped to RAL soon.Power supplies have arrived and will also be shipped to RAL soon.Operating points

Flip mode Solenoid mode

200 MeV/c 240 MeV/c 200 MeV/c 240 MeV/cCurrent 187.14 224.75 94.15 113.09

Current density NbTi 584.82 702.35 294.23 353.41

Current density coil 104.75 125.80 52.70 63.30Bz max 3.090 3.711 2.598 3.121Bpeak conductor 6.264 7.523 3.763 4.520

HTS Lead thermal link

Some off-line measurements are being made on the thermal link between the HTS leads and the cryocooler mid stage. This is a critical joint.

Found that Cu/Stycast/0.2mm FR4/Stycast/Cu joint is not as good as sandwich with 50µm KaptonKapton is ~ x2 better than the FR4 and can withstand 4kV

R9 Facility

Chiller for cryocoolers

Area cleared and Yellow line for 5 Gauss limit..

Scaffolding

CERN Field Measurement equipment

Schedule

Module/Activity Due DateAFC1 at RAL JulyAbsorber integration and test +3mths elapsedAFC2 at RAL SeptemberAbsorber integration and test <3mths

END