1. TARGET HALL OVERVIEW I. Bailey Cockcroft Institute / University of Liverpool

2. Recap of Talks from RAL Positron Source Meeting, Sep 2006. Andriy Ushakov, DESY FLUKA simulations with simple target geometry. For baseline design, equivalent dose rate for a Ti ( W) alloy target wheel, 1 week after shutdown, after 5000 hours of running, 1m from wheel is ~170 (120) mSv/h NB 65m (43m) of undulator assumed (shorter than baseline). Reduction to level of 0.03mSv/h requires ~15cm of Pb shielding EU exposure limit is 20mSv/year See presentation in tomorrow’s target session. Remote-handling needed (c.f. 20mSv/h manual worker limit at LHC)

3. Tim Broome, RAL –Remote-handling orientation (vertical / horizontal) –Replacement strategy (modular / component) –Required time for exchanging targets? Recap of Talks from RAL Positron Source Meeting, Sep 2006.

4. Handling Concepts - Horizontal Services remain connected, target moved to an integral remote handling cell for replacement. T. Broome, RAL, Sep 2006

5. Handling Concepts - Vertical Services disconnected and target removed to a storage facility. Later can be worked on in a separate remote handling facility Smaller footprint than horizontal but transfer flasks are required T. Broome, RAL, Sep 2006

6. Comments on the proposed target design Remote Handling must be considered from the outset All service connections have to be remotely handled so choose a system with a minimum of connections Consider radiation cooling (to eliminate problems with the water systems (seals etc) If water cooling is used why not drive the wheel with the water and eliminate the motor Instrumentation is often a key item and can be the life limiting and present a significant remote handling challenge It looks like remote vacuum connections will be required. For a 10 -8 mbar vacuum this will require development Definition of end of life of the target assembly is useful but very difficult T. Broome, RAL, Sep 2006

7. Chris Densham, RAL –The ISIS Horizontal layout used as starting point –Complete target and services system to be on rails and moved in and out of the beam –Vertical installation may have some advantages (space, cost) but likely to be slower to change targets (days or weeks - not hours) Recap of Talks from RAL Positron Source Meeting, Sep 2006.

8. Single Target Station - Side View Target module Remote handling cell Services trolley (target cooling, cryogenics for solenoids) Service lines C. Densham, RAL, Sep 2006

9. Target hall layout 50 m UPT Target AMD Pre- Acceleration system A (Target module withdrawn into hot cell) Target AMD Pre- Acceleration system B (in operation) Electron linac C. Densham, RAL, Sep 2006

10. Topic Action Items: D.Target Hall Vinod Bharadwaj More activation/damage calculations Identify what numbers are needed from the calculations Figure how to do the simulation – which program(s) etc. identify people to do the simulations include detailed layout of hardware: OMD, SW RF, TW RF, solenoids, shielding Define target hall dimension requirements target hall occupancy needs needed shielding what is in the hall and what is on the surface scenarios for all the needed repair/replacement operations KAS target hall Does ILC plan to have a central hot cell facility? e+, dumps etc. will it be useful for the positron stuff Re-visit two/one target requirement (availability, R&R time,……) Topic Summary - RAL positron source meeting, Sep 2006.

11. Progress Since RAL meeting More sophisticated activation simulations interfacing FLUKA to ASTRA, etc (see Andriy Ushakov’s presentation) More sophisticated FLUKA input geometry (L. Fernandez-Hernando, ASTeC, DL) Cost driven decision to adopt smaller target hall Vertical remote-handling concept (c.f. SNS and PSI) developed by RAL Fortnightly remote-handling and activation phone meetings started.

12. 5 cell rf cavity. e.g. s/c OMD Target wheel (includes water channel) L. Fernandez-Hernando,DL, 25/01/2007 Drive shaft (includes water channel) Target Geometry Drawn in SimpleGEO A few glitches found in exporting geometries between SimpleGEO and FLUKA. Should be able to begin simulations in a few weeks.

13. Alternative Target Hall Layout Mini target hall 2 target stations Surface reprocessing ~25% of full target hall size (~250m 2 ) V. Bharadwaj, 17 th October 2006

14. Alternative Target Hall Layout V. Bharadwaj, 17 th October 2006 Micro target hall 1 target station Surface reprocessing ~8% of full target-hall size (~100m 2 ) New baseline.

15. Remote Handling and Target Removal EUROTeV: WP4 (polarised positron source) PTCD task I. Bailey, J. Dainton, L. Zang (Cockcroft Institute / University of Liverpool) D. Clarke, K. Davies, N. Krumpa, J. Strachan (CCLRC Daresbury Laboratory) C. Densham, J. Rochford, B. Smith, M. Woodward (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)

16. Target Removal/Replacement Showing Storage Cell M. Woodward, 24 th Jan 2007 Beam Pipe

17. M. Woodward, 24 th Jan 2007 Target Module and Plug with Support Services Cryocooler (if required) + vacuum pump + water pump Details of vertical drive for target wheel not yet considered.

18. M. Woodward, 24 th Jan 2007 Target Module and Plug with Support Services (2)

19. Estimated Target Changeover Times Remove 1.Switch off and isolate electric power to magnets (overhead cable system) 8 2.Switch off and isolate power to Target Wheel motor 8 3.Stop Target Wheel coolant pump 4.Blow out Target Wheel 5.Remove/disconnect water supply 6.Close actuated vac valves on beam line each side of target station. 1 7.Close actuated vac valve on AMD side of target station 2 8.Close actuated vac valve on NC Accelerating Cavity side of target station. 9.De-pressurise both pillow seal units2 10.Attach lifting rods4 11.Attach lifting beam 12.Lift target station complete with shielding, vac pump running and cryocooler running 2 13.Place into parking enclosure 14.Disconnect from crane1 ~28 Hours Removal M. Woodward, 24 th Jan 2007

20. Estimated Target Changeover Times ~25 Hours Replacement Replacement 15.Connect lifting rods and beam to new unit with shielding, vac pump and cryocooler running – already under vacuum and cold 2 16.Lower into position – locate2 17.Pressurise and activate both pillow seal units4 18.Open actuated vac valve on NC Accelerating cavity side of target station 2 19.Open actuated vac valve on AMD side of target station 20.Test target station vacuum for leaks1 21.Open actuated vac valves on beam line each side of target station 2 22.Replace/reconnect water supply1 23.Reconnect power to target wheel motor1 24.Test wheel motor. Test water flow through target wheel 2 25.Connect electric power supply to magnets8 TOTAL REMOVAL + REPLACEMENT 53 M. Woodward, 24 th Jan 2007

21. Discussion Topic Action Items: D.Target Hall Vinod Bharadwaj More activation/damage calculations Identify what numbers are needed from the calculations Figure how to do the simulation – which program(s) etc. identify people to do the simulations include detailed layout of hardware: OMD, SW RF, TW RF, solenoids, shielding Define target hall dimension requirements target hall occupancy needs needed shielding what is in the hall and what is on the surface scenarios for all the needed repair/replacement operations KAS target hall Does ILC plan to have a central hot cell facility? e+, dumps etc. will it be useful for the positron stuff Re-visit two/one target requirement (availability, R&R time,……) Sufficiently understood? FLUKA + …? Regular meetings between DESY, DL, Liverpool, ANL, SLAC Underway between DL and DESY Started this process Any progress?