Eric Prebys, Fermilab Program Director, LARP July 10, 2012

Management:  LARP management is to be commended for establishing a well run program.  LARP has adequately addressed the recommendations from the last review, however, a transition plan from R&D to construction needs to be made available. Magnet Systems:  The review panel was pleased with the management and coordination among the 3 labs of the magnets R&D program and the progress to date.  The effect of beam losses and radiation damage within the magnets is critically important to the operation and performance of the magnet systems, and these effects must be taken into account in the magnet design and construction Review Responses July 10, 2012

Accelerator Systems:*  There has been considerable good engineering progress on the complicated rotating collimator. However, the leaks in the jaw cooling system will require subsequent prototyping before this option could be seriously considered.  The committee is encouraged by the results of the hollow electron beam lens used as a scraper. We encourage LARP to proceed with discussions of how to transfer the hardware to CERN to continue the effort.  We encourage further development of the wideband fast kicker technology which is interesting and potentially useful in many other applications  Crab cavity design team is to be commended for making excellent progress since the 2010 LARP review.  We strongly encourage the ongoing [Energy Deposition] work on simulation and particularly the benchmarking of the codes. Discrepancies between experiment and simulation need to be understood.  LARP has done a great job providing instrumentations to LHC. These instrumentations are performing extremely well and are critical to LHC success Review Responses *a small subset of the original, which were distributed amongst several sub-topics July 10, 2012

1. LARP management should provide a detailed plan, including budget profile, to DOE on transitioning from LARP R&D into HL-LHC by Feb 1, Provide to DOE by Feb 1, 2012, a prioritized list of LARP R&D activities indicating which will be emphasized and which will be reduced.  We have addressed this both by integrating LARP activities into the CERN HL-LHC project and by drafting a strategic plan, comprised of LARP activities and other potential US projects related to the LHC. July 10, Review Responses

1. The panel strongly recommends that LARP accounts for the energy deposition and radiation damage from beam losses in the construction of all future test coils, and LARP begins an intensive testing and integration of advanced radiation tolerant insulation systems into the test magnets.  We agree, and are working to coordinate these efforts with the HiLumi study. In response to this recommendation, we have dramatically increased out energy deposition modeling, while CERN is planning a series of material tests in the HiRadMat facility. 2. In future reviews present the radiation and heating damage effects jointly to both the accelerator and magnet panels.  Agreed July 10, Review Responses

3. Develop a detailed plan including budget and schedule to advise DOE on future transition to an HL-LHC construction project. Include recommendations on how the US LARP magnet team would play a significant role in this upgrade project.  This has been a major theme and our combined LARP/HiLumi meetings, as well as a series of collaborative meetings with CERN, and we have presented the current state of this plan. 4. Begin integrating cryogenic and cryostat design into the magnets.  This is a major theme of the HL-LHC design study, in which we are fully involved. In addition, we are developing a second generation mechanical structure that more directly addresses some of the production issues, including cryogenics 5. Seek qualified alternate strand vendors (CDP) and improve piece length.  We have made a strong case that CDP should focus on this goal for the next several years, rather than shifting its effort toward longer term objectives that have been pushed by other programs (muon collider, Bi-2212 collaboration). See LTSW presentation.  During the CM17/HiLumi meeting, conductor development issues have received particular attention. A working group was formed and initial goals/specifications for a combined effort involving european and US vendors have been formulated. An exchange of wire between LAR and CERN has also been initiated which will allow to gain experience with the performance of PIT wires in LARP models July 10, Review Responses

Collimation: 1. In discussion with CERN and DOE determine if the prototype should be tested at the SPS for operational and impedance considerations; or should be dissected at SLAC. After documenting lessons learned, terminate rotating collimator work within LARP.  We remain committed to bringing the rotatable collimator R&D to a point of fruitful closure. CERN has shown no interest in testing a collimator which cannot be cooled, so we are building new collimator which will soon be ready to ship to CERN for testing. This work was done mostly with carryover from FY11, and has used little resources this year. July 10, Review Responses

Crab Cavities: 1. Work with CERN-RF Group to finalize engineering specifications and a realistic R&D work plan with resources to address cavities prototyping consistent with the HL-LHC schedule.  Crab cavities are an official part of the HiLumi-LHC design study, and this is a key part of the goal. LARP is working with the DOE to understand the ultimate role of the US. 2. Complete final cavity design that merges ideas from ODU-JLab parallel bar and SLAC ridged waveguide concepts.  These concepts have been merged and are now being pursued as a single design. 3. Prepare and submit a limited-scope plan to DOE requesting potential funds to fabricate a prototype “bare” cavity per above recommendation for vertical cryostat test.  We are working toward this goal within what we assume will be a flat LARP funding profile. July 10, Review Responses

Beam Dynamics: 1. Understand and isolate the discrepancies, feeding back into code improvements. Document and present it at the next review.  OK July 10, Review Responses