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CLIC Technical Committee - Meeting #60
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Europe/Zurich
18/3-030 (CERN)
18/3-030
CERN
CLIC Technical Committee - Meeting #60 (05 Jun 2012)
Present: Kurt Artoos; Michael Burns; Marco Buzio; Nuria Catalan Lasheras; Bernard Jeanneret; Andrea Jeremie; Helene Mainaud Durand; Michele Modena; Stephan Russenschuck; Hermann Schmickler; Daniel SchulteChaired by: Dr. Schmickler, Hermann
General Information
A first meeting about the klystron developments for 1GHz has been schedule this afternoon.The budget allocations between new and old budget codes will be made soon.
Alignment status. Plans for 2012. H. Mainaud.
Helene presented the four different working packages and the status of the collaborations for survey and alignment (see slides).Several methods for absolute alignment have or are being tested in the lab and in TT1. The possibility to test them in a larger scale in TZ32 is being discussed this week. The relative alignment of elements will be provided by sensors and actuators currently being tested in the two beam module prototypes in the lab and in CLEX. For the machine detector interface, no realistic mock-up has been chosen yet. As a test bench for survey in the detector vicinity, Hermann suggested to use one of the LHC experimental caverns. Necessary installations could be done during the LS1. (Action: Helene)
The presentation continued introducing the main advancements on development of sensors and actuators. Herman asked if the aging of cam movers was being considered. Kurt replied that creep of the CAM contacts is probably less important as it can be corrected by the feedback with the wire, other long term effects such as wear can be important if it acts on the functioning of the cam movers. In particular, wear has been a problem on the SLS cam movers during the prototyping and they added an extra surface layer. A major issue is the tolerance to radiation of some components like CDDs but also some materials for which no data exist. This issue is shared also with the stabilization, beam instrumentation and power supplies at least. A joint effort should be coordinated between all the actors to propose a test campaign of different components against radiation (Action: Hermann )
Hermann suggested to add milestones to the workflow and reduce the number of choices as it is too large to be pursued with reduced resources. Redundant devices may show a definitive shortfall (radhard oWPS) and could therefore be dropped to liberate resources. At the same time, it was felt that no technology should be completely abandoned as in ten years, it may become feasible or cheaper. This is specially the case of capacitive straight wire where the patent preventing in-house development could become obsolete soon.
Herman proposed a meeting in 2-3 months to discuss the achievable targets from survey and alignment and feed these numbers back into the simulations.
Concerning the collaboration with SLAC, the present situation is considered excessively expensive. An action is needed at project level to discuss the collaboration terms for this and other working packages. (Action: Hermann )
Stray field magnetic measurements. J-B. Jeanneret
The tolerance of the CLIC luminosity to the variation of magnetic field depends on the frequency but it is in the best case about nT level. Measurements done in Fermilab showed results between 10 and 1000 times this specification. At CERN the only existing measurements were done in the LHC during 2012. Bernard and Marco will finish the analysis of what was measured as a summary of what we have today. (Action: Bernard and Marco)Additional measurements in a better environment will be needed. A PhD student could start in January to perform these measurements and to fold it back into the beam by introducing the findings into the simulation. The most probable sensors to be used would be flux gates with variable inductances inside.
The expected result could be to have more stringent requirements on the civil engineering in the form of steel content or structures periodicity.
Hermann reminded that the magnetic measurements working package led by Stephan has no budget allocation to it. Some money could be still allocated following a proposal. (Action: Stephan).
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