UK Target Update

1. UK Target Update Ian Bailey University of Liverpool / Cockcroft Institute EUROTeV: WP4 (polarised positron source) PTCD task I. Bailey, J. Dainton, L. Jenner, L. Zang (Cockcroft Institute / University of Liverpool) D. Clarke, K. Davies, A. Gallagher, N. Krumpa (CCLRC Daresbury Laboratory) C. Densham, M. Woodward, B. Smith (CCLRC Rutherford Appleton Laboratory) J.L. Fernandez-Hernando, D.J. Scott (CCLRC ASTeC Daresbury Laboratory / Cockcroft Institute) P. Cooke, P. Sutcliffe (University of Liverpool) In collaboration with Jeff Gronberg, David Mayhall, Tom Piggott, Werner Stein (LLNL) Vinod Bharadwaj, John Sheppard (SLAC)

2. UK Target R&D Involvement • Target simulations (with DESY) • Detailed geometry for FLUKA (presented in target hall session) • Planned GEANT4 spin transport simulations • Eddy current simulations (Jim Rochford - this session) • Photon Collimator simulations • Beginning FLUKA simulations • (Lei Zang, University of Liverpool) • Target wheel prototyping (this talk) • Proposed 3 staged prototypes sited at DL • Pending funding • Remote-handling solutions • RAL (presented in target hall session) • Alternative target materials • Alternative metals, ceramics (alumina + zirconia), etc • RAL (work underway)

3. Proposed Timeline (100% funding scenario)Stage 1 • Construct and test a prototype to establish the mechanical stability of the target wheel assembly in the field of a strong magnet. Does not include internal water-cooling channels. Does not include vacuum vessel or vacuum conditions. • Apr 07 - Design of first target prototype wheel complete. • May 07 - Infrastructure in place at Daresbury Laboratory. • Jun 07 - Design of target test rig and instrumentation complete. • Aug 07 - Construction of target test rig complete. • Aug 07 -Construction of first prototype complete. • Nov 07 - Initial testing of first prototype complete. • Feb 08 – All testing of first prototype complete. • Mar 08 - Data from first prototype fully analysed.

4. Proposed Timeline (100% funding scenario)Stage 2 • Construct and test a prototype to demonstrate operation of the target assembly when cooling system is operated in vacuum conditions. Testing both with and without magnet depending on conclusions of stage 1. • Nov 07 – Design of second target prototype wheel complete. • Jan 08 - Design of upgraded target test rig and instrumentation complete. • Apr 08 - Construction of second prototype complete. • Apr 08 - Upgrade of target test rig complete. • Jul 08 - Initial testing of second prototype complete. • Oct 08- All testing of second prototype complete. • Dec 08-Data from second prototype fully analysed

5. Proposed Timeline (100% funding scenario)Stage 3 • Construct and test a prototype to establish performance of the target cooling system with heat load. Using latest target design and latest capture optics design if appropriate / available. • Mar 08 - Identify possible technologies for simulating thermal load. • Aug 08 - Design of thermal load source and interface to test rig complete. • Nov 08 – Design of upgraded target test rig and instrumentation complete. • Nov 08 – Design of third target prototype wheel complete (if needed following stage 2). • Feb 09 - Upgrade of target test rig complete. • Mar 09 - Installation of thermal load in test rig complete. • Mar 09 - Construction of third prototype complete. • Jun 09 – Initial testing of third prototype complete. • Oct 09 – Final testing of third prototype complete. • Feb 10 – Data from third prototype fully analysed. We don’t expect 100% funding!

6. Stage 1 Prototype Target Wheel Sectional view • 1m diameter wheel with simplified structure compared to current baseline target wheel. • Optional cantilever drive shaft (deflection measurements) • Consistent with water-cooling (to be confirmed by LLNL) • Uses Rigaku ferrofluidic feedthrough and is consistent with Deublin water union. • Motor being sized for rotation up to 2000rpm.

7. Stage 1 Prototype Target Wheel (Hub Detail) • Detail showing drive shaft and wheel hub. • Reducing drive shaft to 2” diameter allows use of standard feedthrough and water coupling at 2000 rpm.

8. Stage 1 Prototype Target Wheel and Test Magnet Sectional view

9. Test Magnet • Default option is to use magnet already based at DL • GMW dipole electromagnet, model 3474-140 • Normally used for Hall probe calibration • Possibility of s/c magnet from BINP? • 1800 kg • water-cooled • adjustable pole gaps

10. Future PTCD Activities • Target Prototyping • Proposing 3 staged prototypes over 3 years (LC-ABD funding bid) • Measure eddy current effects • top priority • major impact on design • Test reliability of drive mechanism and vacuum seals. • Test reliability of water-cooling system for required thermal load • Develop engineering techniques for manufacture of water-cooling channels. • Develop techniques for balancing wheel. • First prototype mechanical deisgn progressing well. • First prototype instrumentation and electronics design starting. • Remote-handling design • Essential that remote-handling design evolves in parallel with target design. • Determines target hall layout and cost. • Evaluaitng change-over times. • Photon Collimator design • Use realistic photon beam. • Activation simulations (in collaboration with DESY). • Thermal studies and cooling design. • Variable aperture (optimise in association with beam jitter simulations)?