1. Radiation Shutter Re-Purposing Roy Preece STFC RAL 18 th December 2014

2. Final Step Radiation Shutter 2 Direct Drive motors Lead Windows ~ 50mm thick Spectrometer Solenoid Flange This line of bolts hold the Lead window to the door Edge welded bellows Will be required at these junctions Control cabling feedthrough (Both sides) Currently a free port – could be additional vacuum (both sides)

3. Final Step Radiation Shutter 3 Radiation shutter on the test plate. Control software regulates the speed Limit switches for open and closed Manual operation rods shown – to be used in the event of motor failure Limit switches Direct drive motors Angled split line Mounting bolts

4. Final Step Current Design 4 Arrangement of the Cooling Demonstration utilising the current Single Cavity Test chamber design

5. Final Step Absorber extension 5 Remove the lead material Utilising the same fixture PCD of holes mount extension rods Mount the Half disc inside a clamp (holes in the LiH half disc would probably be quite weak with the risk of failure) Mounting the absorber to 5mm face to face would not be a problem. The flanges of each device (Solenoid and RF chamber) can be used for longitudinal alignment.

6. Final Step Absorber section gap 6 What’s the effect of the gap between the half discs? What’s the maximum gap before detrimental effects on the physics ? The control software can drive the sections together at a very low velocity reducing possible chipping of the LiH coating. Limit switches can hold the surfaces apart If held together on the machined surfaces the gap could be 0.25mm – 0.5mm Beam Current Lead shields

7. Final Step Conclusions The current design and assembly can be used Minimal additions to the design – extension rods Distance the absorber is away from the RF window will be adjustable up to the point of channel assembly. Defined method of assembly will be needed The absorber disc will protrude into the RF chamber volume The RF chamber will not be able to slide in the way that the Focus coil does at the moment Two Radiation shutter assemblies are available Control system has been tested Mechanical systems have been tested Manual operation parts will require some work for vacuum Current design will only attain 10-3 mBar during operation With edge welded bellows installed to the assembly – 10-7 mBar would be achievable These will be standard parts 7 Edge Welded Bellows