1. Positron Source Update Jim Clarke Deepa Angal-Kalinin James Jones Norbert Collomb At Daresbury Laboratory and Cockroft Institute 21/07/2009

2. AD&I Layout (from TILC09) Standard Tunnel Cavern with Shaft above To DR To IP Remote Handling BDS Fast Abort Kicker Undulator Target, NC Linac, Dumps 400MeV NC Linac 5GeV SC Linac Dump Auxiliary Source Drive Beam Shielding to allow access to IP when e+ running? Five separate beams in the tunnel here ! Electron RTML 5GeV Areas that need to be investigated in detail. There are potentially big savings to be achieved. These areas are however, tricky to deal with.

3. Positron Source Update 21/07/2009 3 Systems in very close proximity. Positron Source Beam Delivery System RTML Close collaboration required

4. Recall the RDR e+ layout! 150 GeV end of ML Undulator Chicane Undulator section 2 nd Chicane (back on Axis) RTML Target Area with Remote Handling (very faint box) Positron Pre- Accelerator chicane Positron Transfer Line (on ceiling) Towards I.P.

5. Positron Source Update 21/07/2009 No clear path to transport equipment into position. Had to go over or under chicane to reach systems downstream. Emergency escape route requirement means a service tunnel was essential. Large cavern for Target Area required. In short, could do better!

6. AD&I e+ layout (after 2 iterations) Undulator at 250 GeV (note positional change) RTML (assume can remain as per RDR) BDS chicane (1.5m off-set instead of 2.5m and change in direction) Target Area and Remote Handling (‘Box’ in faint yellow) Positron Pre- Accelerator (note, change in direction) 2.5m off-set remains to separate Positrons Electron Dump Cavern could be ‘reduced’ to an ‘Alcove - type’ Towards I.P. Much better solution, but where will the “Fast Abort” beam line go?

7. AD&I e+ layout continued. Proposed Fast Abort Layout (Feasibility Investigation in progress) Need to check Remote Handling Area for clearance. Can RTML magnets and abort beam line magnets coexist in close proximity? Preliminary Beam Studies (Deepa and James) indicate that this solution may increase length of machine by approx. 300m. This solution could further increase cost in terms of equipment required. Starting to look expensive. 250 GeV Beam from Main Linac to be taken to ceiling (diagonally up and towards I.P). Lattice design is complex and Beam acceptance is governing this. Installation and maintenance could be difficult!! Plenty of room for access (cautious maybe) 0.8m Approx. 2m Approx. 1.8m

8. AD&I e+ or BDS(?) layout ‘continued’. Fast Abort Line could be “off axis” in this direction. Towards I.P. Undulator Section 11MW (??) Dump requires approx. 3m shielding. Is it feasible to have short tunnel branching off? Need to investigate cost for this alternative and compare with previous solution (provided tunnelling is possible). RDR Lattice design exists (for large energy acceptance). 250 GeV (500 GeV) Main Linac end. Fast Abort not to scale. Sacrificial Collimators can move from RDR design to this location (before Undulator).

9. Aim is to bring PPA chicane on axis with Undulator. May permit PPATEL to move into BDS plane. Investigation as to space availability for 5 GeV SC LINAC and other components underway soon. his is outside the current CAD model approx. 100m down beam. Towards I.P. AD&I e+ layout (after 2 iterations) “Large” Cavern is still required. Look at improvement.

10. PPA in BDS plane and on axis with Undulator. Moved to end of Positron Capture chicane. Remote Handling Area envisaged to take the shape of 6.6m Dia. Shaft (based on 1m shielding requirement). Towards I.P. AD&I e+ layout (after 2 iterations) Cavern turned into an Alcove and drastically shortened. This solution can fit all systems into a Diameter 4.5m tunnel. Lattice design looks O.K. (detailed Beam Dynamics study to follow). 9.5m 48.5m

11. AD&I e+ layout continued. RTML clears Remote Handling Area May need a further “Alcove” for Auxiliary Source Diagnostics around here. Remote Handling can take ‘shape’ of shaft. May need some shielding around electron and photon Dump. Collimator, Target Wheel, AMD and 2 x Standing Wave Accelerators need to be lifted vertically out.

12. AD&I e+ layout continued. May need a further “Alcove” for Auxiliary Source around here. Work In Progress Towards I.P.

13. Positron Source Update 21/07/2009 Summary: Proof that we can fit everything into single tunnel. Close collaboration (bi/tri-weekly face to face meetings) reduce iterations and time between suggestions/solutions. Whiteboard/CAD or other visualisation methods aid A LOT to identify opportunities. Great feeling that we arrive at optimum solution soon. Information ready to go to other closely linked Work Groups for comment and suggestions. Cost estimates to be done to decide and verify solution to choose. Any questions or comments, please.