1. MICE Collaboration Meeting Harbin, China 13 – 17 January 2009 Progress on AFC since the PRR By Wing Lau, Oxford University

2. A re-cap of where we are on the AFC module supply contract. Contract was for the design and supply of 2-off FC modules with the option to purchase the third one at a later stage; Contract to Tesla was signed in June 2008; First hiccup was the conductor size and the availability of a continuous conductor length. At the end, we agreed to go for the Type F 174 wire: Conductor type: F174 (Final purchase F 180 – number of filaments) Dimension bare 1.52 x 0.95 mm² Formvar insulated 1.57 x 1.00 mm² Consisting of 174 NbTi filaments (final purchase – consists of 180 filaments) In a Cu-matrix Ratio Cu : NbTi abt. 4.0 : 1 Core conductor with Nb-barrier Core Alpha abt. 0.45 Corner radius > 0.20 Filament diameter abt. 48 µm (final purchase is now 46 µm ) Ic at 4.2 K; 0.1 µV/cm, 5 T – 686 A RRR > 80 Purchase order for the conductor was released at the end of July to allow for a delivery in late March 2009. This is one of the critical long lead items.

3. The preliminary design review was held on the 12 th of August. It did not go as well as expected with a number of technical issues (Thermal modelling, Quench protection design and cold mass forging) not finalised. A subsequent meeting on the 24 th of September cleared some of these outstanding items. Tesla had done a lot of work since the initial preliminary design review, though the bobbin design was still not satisfactorily completed. The review paved the way for further detail design work in rediness for the PRR (Production Readiness Review) A Production Readiness Review was held on the 6 th - 7 th of November (originally scheduled for the 9 th of October) A list of items which require re-work / design modifications were identified and agreed on. These are listed in the following table with af=greed actions.

4. Items for re-workAgreed actionsProgress to date 1.Thermal model: Current lead uses a high RRR value (50 c.f 10 or less) Tesla to re-run thermal model with lower RRR value completed Coil assumes an isotropic block of copper Tesla to remodel copper block using different and realistic conductivities in the three directions, as they did in their quench analysis Done Contact resistance on cryocooler 1 st stage looks too optimistic Tesla to confirm values used, including values in contact area. Conical surface area increased from 5800mm 2 to 8000mm 2. Issues with trap volumes spotted. May have to make hard physically connection internally via access port. Further to the review, Tesla has now completed the thermal modelling on the new bobbin configuration with external cooling

6. Summary a. The maximum coil temperature calculated is 4.51K which is still lower than the criterion(4.8K) but leaving only 0.3K margin. b. Calculation results satisfied all design criteria.

11. Input data -- Dimension & material data of the turret system including current load

17. Thermal conductivity of each interface after the iterative calculation CryoMech cooler PT415 cooling capacity map

18. Items for re-workAgreed actionsProgress to date 1.Thermal model: Current lead uses a high RRR value (50 c.f 10 or less) Tesla to re-run thermal model with lower RRR value completed Coil assumes an isotropic block of copper Tesla to remodel copper block using different and realistic conductivities in the three directions, as they did in their quench analysis Done Contact resistance on cryocooler 1 st stage looks too optimistic Tesla to confirm values used, including values in contact area. Conical surface area increased from 5800mm 2 to 8000mm 2. Issues with trap volumes spotted. May have to make hard physically connection internally via access port. 2 Conductor splicingTesla to demonstrate satisfactory technique Tesla will do the first run in the new test facility on another conductor. 3Bobbin issues: Consider indirect cooling to allow higher stress allowable MICE to agree to increase coil ID to 268mm and end plate thickness to 35mm. Modelling now completes. Looks OK. Stress report available. Load cases, including transport load, identified Tesla to ensure all case loads are analysed Winding load disappear on Cool- down. Reason for active quench. 4 No. of redundancy in their active quench protection Tesla to consider this in their design Work has now finished. Tesla proposes to use active quench detection and quenchback.

24. 5 Size of vent line and its effect on heat load at critical areas Tesla to review this Being incorporated as part of the turret design. 6 Tolerance on vessel flange – implication on overall module alignment MICE to confirm beam height, and Tesla to advise on achievable tolerance Awaiting Andy Nichol’s confirmation 7Cryocooler and HTS Leads Implication from indirect cooling; size of condensing lines; sensitivity to impurities at cryostat bottom were raised Tesla to address these issues Model set up and is being worked on. Flexibility on HTS leads to cater for thermal contractions; provision of thermal clamping; positioning of Leads and motor to suit magnetic field etc Tesla to address these issues Change in the turret design made that improves the tolerance to stresses induced by thermal contraction. Fiducial mark on lead to allow ribbon 90 o to field direction. Shield around motor reduce field to 20 Gauss around cryocooler. 8 Consider AL 1100 (instead of 6063) for radiation shield Tesla to consider Thermal model showd good results with 6063. To be decided at the time 9 Confirm UTS value of S-glass straps Tesla to confirm Test results suggest UTS of 1.6 GPa (Futura report available now.) 10Supports for current leadsRAL to advise on routing and support locations Andy Nichol to advise 11Instrumentation & ServicesTesla to provide inventory Inventory is being compiled. Expect to complete soon.

25. 12 Hydrogen system Move the inter-connectors further up into the turret Tesla agreed New turret design reflects this change. Cryocooler 1 st stage may need heat exchanger MICE (TB) to advise Heat exchanges are being incorporated to the cooler 1 st stage, but Tesla is having difficulty incorporating the length of heat exchange. I may still be possible. OK to route Instrumentation cables through vacuum port Tesla to confirm Requires an inventory of instrumentation. This is in hand Confirm that the two vacuum systems can withstand atmospheric / vacuum combination ANSYS model confirmed this is OK. Report has been circulated for comments. Dummy Safety window needed to gauge warm bore MICE to provide dummy window Wing Lau to provide this – this is in hand. 13 Other items Fault cases need to be looked at by Tesla Such as over-current, wrong polarity in AFC and other modules Work already started. Weld qualificationTesla to add In hand DisassemblyTesla to ensure that critical items can be removed and replaced etc Access port added on the OVC for access to HTS leads which have been moved to the outside of assembly. Crycooler can be removed from top plate. Access to wire looms is via side access port etc.

26. Summary of the AFC status: Bobbin Issues Following Document was submitted to MICE team on5th January:- MICE AFC Bobbin linearization report – this analysis proves 6061-t6 Bobbin with the increased sizes detailed therein will meet the stress seen during operation. Document is on Web page for comment by MICE team. Vacuum Vessel Following Document was submitted to MICE team on5th January:- MICE AFC Vacuum Vessel – analysis of the vacuum vessel integrity under differing vacuum/pressure combinations. Document is on Web page for comment by MICE team. Suspension System S-Glass Testing results submitted. Document is on Web page for comment by MICE team. Further stress modelling of the suspension system is continuing. MICE Quench Protection The final design report is now available. It concluded that an active Quench detection and protection system is needed.

27. Indirect Cooling Thermal Model Thermal model set up and ran, A simplified excel model has already been run and a report has been submitted on 6th January. Turret Redesign The turret redesign incorporating the changes for the Vent line, HTS lead configuration, Hydrogen system interconnects, Hydrogen system heat exchanger and accessibility issues are nearing completion and will be available early next week. Instrument Services Listing has commenced Fault Cases This has commenced Critical Items – Vessel Flanges Method of manufacture will be detailed to ensure tolerances can be achieved. Superconductor Splicing Further work on this will be undertaken at Tesla prior to receipt of Superconductor which is still on schedule for delivery end March09. Project Plan This has been updated to show current status. It shows a delay of 39 days. Delivery of the 1 st module is now the beginning of January 2010

30. Documents relating to the AFC All the technical reports from Tesla are now kept in the STFC web page:- www. eng-external.rl.ac.uk/miceafc This webpage is managed by Tom Bradshaw and is password protected. Please email me or Tom for detail.