1. Acceptance Criteria for the Decay Solenoid Tom Bradshaw Mike Courthold Matthew Hills

2. Work areas 1.Vacuum system a)Repair of leaks b)Repair of 2 nd Solenoid pumping rig 2.Quench detector 3.Linde refrigerator 4.Magnet tests 5.Documentation

3. Vacuum system Repair of leaks Need to make sure that stress relief of vacuum flange is sufficient to fix leak on transfer line Risk is that repair of transfer line may be required; therefore we need to understand the situation sooner rather than later Transfer line support frame is manufactured and will be installed as soon as the painters’ scaffolding around the solenoid is taken down Will probably tolerate small leak on DS vacuum vessel, unless it can be fixed with leak sealant Repair of 2 nd Solenoid pumping rig Pump stands manufactured Repair of turbo and controller 'in hand‘ Small amount of re-wiring required, which will be done by the DL electrician

4. Quench Detector Modular design of quench detector channels allows for easy repair There are sufficient spares available from PSI Recent investigations show that there may be issues with the power supply and battery backup degrading Advice is that the PSU and battery backup are replaced. (Steve Griffiths estimates this will cost approximately £5k + 10 days of staff effort)

5. Linde Refrigerator Chiller repair is still a short term issue Linde supervised cool-down to set control parameters will be the next run There is the issue of the circulating gas purity and there are some issues surrounding this that need resolving. In summary, there is a difference between the gas purity measured on an RGA and that measured using the Linde equipment (but this has yet to be confirmed). A more immediate problem is the availability of a suitable gas analyser to check the gas purity before the next run.

6. Magnet test Thorough test of quench protection system (achieved) Soak test at 1/4 power for 48 hours, followed by; Soak test at full power for 48 hours

7. Documentation List Notes on documentation (introduction) User Manual Quench detection system Power supply Vacuum system Refrigerator Risk assessments Training material Photographs History log of work done on the system Maintenance schedule and procedures

8. Schedule Summary Magnet testing complete Completion of fridge control optimisation and testing (coincides with end of August shutdown). Estimated additional time required if a new flange has to be welded onto the transfer line to fix leak

9. Acceptance Criteria The solenoid can be ‘signed-off’ for normal running when the following have been achieved. 1.Magnet tested at full current for an extended period (i.e. 48hrs) 2.All vacuum leaks at an acceptable level 3.Fridge operating in a sufficiently autonomous way that cool-downs can be completed without ‘expert’ intervention 4.Quench detector PSU and battery back-up replaced 5.Documentation for (basic) maintenance and operation by non-experts complete

10. THE END