TARGET WORKSHOP – SHEFFIELD HALLAM UNIVERSITY Monday 2 March 2009 The ISIS – MICE interface Eddie McCarron Contents 1.Target alignment with ISIS beam centre line. 2.Target redesign and QA. 3.MICE M113 vessel mods. 4.MICE target removal/installation mods. 5.Actions and aims 1

Transferring beam datum from ISIS to MICE target The beam centre cannot be measured directly. The synchrotron parts are aligned with Taylor-Hobson (TH) datum balls from a fixed grid system in the synchrotron hall. Each part has two TH reference points that are pre aligned with a pair of rails. Taylor-Hobson cup. For dipole. Fixed grid reference tower. The TH points for the MICE vessel are mounted on removable jigs that sit on the flange dowels at either end of the vessel. 2

Target tip is not directly referenced to the synchrotron TH system. The target tip must be referenced to the trial assembly rig in R78 then transferred to the synchrotron to obtain relationship between target tip and beam centre line. 3

Procedure for calibrating the target tip to beam centre line. 1.The telescope is set up to view at a known offset parallel to the beam centre line. 2.The target is driven to a known position by the solenoid. 3.The telescope is moved to view the tip of Target. 4.The mechanical off set is recorded and logged with the reading from the solenoid drive software. 5.The target tip is now calibrated to the vessel dowels. This setting is now transferable to the synchrotron. 4

Target shaft redesign It is clear that the vulnerable parts of the target assembly are the target shaft and the driving coils and both their problems are dominated by F = ma. For the coils to produce ‘F’ they need ‘I^2’. I presume we have minimised ‘a’ and are taking steps to minimise ‘m’. Minimising the gap between the target shaft magnets and the coils would reduce the magnetic field necessary to generate ‘F’ (therefore reducing ‘I^2’). I don’t think this has been addressed. It is also clear that there is a vibration problem. The vibrations are proportional to the acceleration, second moment of area, length and the Young’s modulus of the target shaft. I believe each of these has been addressed. Target assembly Quality Assurance (QA) Following the note* about QA issued 22 May There have been some steps towards fully controlling the Target assembly production to QA methods so that reliable and repeatable assemblies can be installed. It is now time to audit these procedures. To ensure that all our stages are specification driven, inspected, and documented I suggest that an independent QA auditor is consulted. Perhaps SSTD at RAL have someone we can borrow for a day or two. * ‘MICE Target Mechanical Acceptance criteria’ 22 May 2006 attached for reference. 5

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7 Mods to MICE vessel M113 in synchrotron The melting of the target tip endangered the observation window below the target. The window will be moved. A thermocouple will be added to a new VAT isolation valve so the target tip temperature can be monitored. Thermocouple enters here New ISIS pumping port and valve. Beam directionMoved observation windowLighting window

8 TC through Swagelok Mirror Pyrex ceiling Thermal radiation collector on end of TC Swagelok welded into valve by VAT Details of M113 vessel of mods of 9

9 Removal/Installation mods ISIS remove excess grease ISIS instal shim to protect optics from oil. Sheffield to pass all cables through these holes to aid cable safety. All cables to be have pucker labels. Avoid routing cables around these edges. (Or they will be trapped In transport casket). Target assembly partly dismantled in R5.2 after removal from Synchrotron.

10 Actions and aims 1.EM to progress vessel mods for delivery by May Sheffield to provide in-line or quick release connectors to parts on Target assembly to ensure efficient Target installation in synchrotron. 3.Sheffield to route cables through target assembly plate to avoid crushing cables in lead casket transport. 4. Sheffield to use pucker cable labels. 5. Plan acceptance trials for R Appoint a QA auditor (internal or external). of 9