1. Target Design – Status and Plans Chris Booth Sheffield 12 th January 2005

2. Chris BoothUniversity of Sheffield 2 Outline Tests on pre-prototype Prototype Status Plans

3. Chris BoothUniversity of Sheffield 3 Diaphragm spring Target Array of coilsMagnet(s) Position measurement Schematic design Linear Drive

4. Chris BoothUniversity of Sheffield 4 Pre-Prototype Coils potted in thermally-conductive resin Sintered Nd-Fe-B magnets Be-Cu diaphragm spring suspension Water cooling Mounted vertically Timing circuits used to switch coils.

5. Chris BoothUniversity of Sheffield 5 Test Layout (1)

6. Chris BoothUniversity of Sheffield 6 Test Layout (1) Diaphragm springs Coil jacket

7. Chris BoothUniversity of Sheffield 7 Electronics

8. Chris BoothUniversity of Sheffield 8 Control Circuit – Paul Smith Development of first drive circuit –Timing circuit to control actuation –MOSFET H-bridges to switch coils –Coils activated in pairs –8 Hz continuous cycle achieved (without cooling) Start on second drive circuit –Microprocessor controlled –Variable timing allowed –Optical couplers to isolate supplies –Higher current construction –Incorporation of position sensing

9. Chris BoothUniversity of Sheffield 9 Full Prototype Construction Pre-prototype –Not enough acceleration –Insufficient travel –No commutator Full Prototype –Improved magnet design and magnet/coil flux linkage –More coils –Hall switch commutator possibilities

10. Chris BoothUniversity of Sheffield 10 Full Prototype Status/Plans Design almost complete Construction of tooling for coil windings about to start –Coil winding and potting to follow Construction of jig to glue magnets (see fig.) –Magnet cutting and assembly Turning of outer cooling jacket Assembly in present stand (modified) –(about 2 months) Full mechanical and thermal testing

11. Chris BoothUniversity of Sheffield 11 Improved armature design Sectored magnets – fixed together with aircraft glue

12. Chris BoothUniversity of Sheffield 12 Outstanding Concerns Most worries concern the radiation and vacuum environment –Is potting resin acceptable to ISIS? (Sample provided) –May need guide-sleeve to prevent lateral motion – Is special “vacuum plastic” radiation hard? –Are cooling-water feedthroughs acceptable to ISIS? (If not, need more complicated chamber) – fig. –Radiation hardness of magnets (will also try Co-Sm) –Radiation harness of position-sensing electronics (read head and Hall sensors)

13. Chris BoothUniversity of Sheffield 13 Test Layout (1)

14. Chris BoothUniversity of Sheffield 14 Concerns Continued Heat load on target –Vacuum tests to be done with dummy load. Need involvement of ISIS engineers in design Would still like radiation tests and measurements in situ

15. Chris BoothUniversity of Sheffield 15 Possible Schedule?