Minutes of the Steering Group Meetings on October 23-24, 2002

October 23, 2002

1. Saturday morning, conveners are expected to list tasks, responsibilities, costs and timelines to arrive at a combined project chart leading to installation at RAL. This will allow us to come up with an overall schedule and evalute how this matches up with the run-in scenarios. We need to put down sensible dates considering RAL shutdowns, procurement lead times, etc. Of course, a lot of it would be contingent on funding and the funding profile should be factored in. The first detectors (needed to define the beam) should be installed at RAL in 2004. We need to identify the critical items and concentrate on those. Our start dates are predicated on the results of funding requests. To get a significant amount of money from the US Department of Energy, we may need much more detail than is planned for the proposal and the review process takes 1-1.5 years, comparable to LH2 safety review. For now, we can assume that DOE money will be available in FY04, NSF funds may not come in before 04 either. This is a proposal, not a technical design report but we still can't afford to make huge mistakes in cost and schedule estimates. We should indicate milestones where decisions should be made. There are two relevant time scales: funding availability and defendable engineering detail. RAL has taken the letter of intent goal of beam in 04 seriously and is providing substantial resources toward that. Moving that target date would not be well received, hence a technology limited schedule. Whether the RAL review results will satisfy other institutions or they will want to do more by themselves remains to be seen. We have to assume a time scale for the RAL review. Based on the LOI experience, this may be around 6 months. The safety panel (which won't be internal to RAL) isn't even set up yet. Experience with the safety review at Fermilab so far has been positive and hasn't really hindered progress but a project schedule is different from an R&D schedule. We can assume that our design will be deemed safe and require minor changes, not major revisions causing large delays. One can't do the complete review without detailed engineering design but we should consider the requirements/criteria to make sure we don't propose something that's obviously unsafe. We need RAL feedback on this right away. In summary: In doing timelines, costs, etc., administrative delays should not be included but there should be provision in the timing to accommodate them. It would be useful to make another timeline including all the administrative delays, we can put things in the optimum order that way. RAL response should come before the EU funding request. We should tell RAL that we will submit a proposal by Dec. 15 and expect a response in the spring.
2. Going around the groups to check the status, identify needs and pressing items.

   Beam dynamics

   sensitivity studies are important and time consuming. It would be useful to study what we can learn from the experiment that could be applied to the cooling channel design. Many studies were done in the Feasibility Study II and in the CERN reports but not what one can learn from the experiment concerning the neutrino factory cooling channel itself. Performance plots for the 200MHz channel from the ICOOL study are in the NSF funding request, need to complete these. Nonlinearities, chromatic effects, etc. are subtle and complicated. There are also conceptual issues related to software bunching independent of detector performance. Cavity backgrounds are potential showstopper, building the first 201MHz cavity is on the critical path. The coated Be window is important and should be done soon.

   Simulation

   We should put in simple smearing for the noncritical items instead of waiting for full detailed simulation. In particular, we should put in simple TOF information to complete the 6D emittance measurement. Performance as a function of noise level is critical for trackers. This study is already in progress for the SciFi, need to do it for other systems as soon as possible. Having a standard reference background source is important so we have consistent performance studies

   Magnets

   Integration (especially with absorbers) is the main difficulty in the design. Also safety requirements, forces on coils, removal/replacement of the absorbers are important issues. We should write down something sensible in the proposal even if it may not be what we decide to do eventually. Coupling coil to RF cavity integration has some issues but no serious obstacles. We need help from physicists experienced in magnetic field measurements. The Amsterdam group working on this for ATLAS toroids is interested in getting involved in MICE. Alain asked them to join and they are considering it. Dubna may also want to join. Dan will contact Skrinsky to pursue Novosibirsk involvement further (they have been unwilling so far). The question of whether we will use removable absorber windows is important, there are serious safety issues related to potential leaks.

   Absorbers

   Main issues are integration and safety. Many studies going on in parallel including the windows, absorbers in magnetic field, etc. 2195 can't be welded, 6061 can. So, the choice of integration scheme (welded vs bolted windows) affects this part of the design. We have to finalize the convection absorber prototype by next summer

   RF

   Integration issues, in particular couplers, vacuum ports, etc. We don't quite know how much power we can get or the rep rate we can run at. Assume 2 x 4MW at 1-1.2Hz with 0.5-1ms flat top, 23MV/m max on crest. There are also safety issues related to Be windows

At this point we ran out of time and decided to continue the next day

October 24, 2002

For the Saturday morning session, we need timelines, cost estimates and final designs for different systems. Ken L. will collect the timelines and Mike Z. and Paul D. will collect the cost estimates. The steering group will stay Saturday afternoon and put together an overall schedule

• RF continued

  There was a meeting earlier to discuss some details. For the proposal, we will stick with 4 cavities. No information needed except for Be safety. Need someone to look at low level RF system. Helmut will ask Roy Church to serve as an RF convener for MICE. Regarding refrigeration, we can afford to throw away the nitrogen since 8MW x 1ms@1Hz = 8kW which requires only about 1 liter/minute of liquid nitrogen.

  RF backgrounds

  Lab G rates from recent measurements are quite high. The effect is also related to having a configuration in which the electric and magnetic fields are parallel, it may be different for the MICE magnetic configuration. We are still seeing beamlets and trying to understand the behavior, these are steered by the magnetic field and might potentially cause serious problems in other areas in addition to detector backgrounds (bubbles in hydrogen, holes in windows, etc.). The LBNL pillbox cavity in Lab G has not been conditioning well with the magnetic field on. We want to try the Be windows soon,the different material properties should help. Background tolerance for the fibers looks good so far

  Detectors

  No serious technical issues but it all depends on the backgrounds. We need a 201MHz cavity in magnetic field to find out for sure. There isn't much uncertainty and the main issues are background (extrapolation by a factor of 100-200 from measured rates may look bad in the proposal), safety (especially having active detectors inside the field in close proximity to the hydrogen) and electromagnetic noise from the cavities. SciFi will be presented as the baseline in the proposal and the TPG as an R&D project. Cerenkov design has not converged yet.

  Beam

  The beam solenoid from PSI is an issue. We don't know how active it is (or the shielding around it for that matter), so it's not clear if we want to get the PSI solenoid or build one from scratch. Radioactivity levels will be measured at PSI early next year. The plan is to be ready for installing the solenoid during the next long ISIS shutdown. Solenoid is not essential to the experiment, we could use a quadrupole channel with existing components. The proposal will say we will use the PSI solenoid in the experiment but start with quadrupoles first instead for detector shakedown. We need to move the hole in the wall to change the beam angle during the shutdown in any case.

Yagmur Torun - torun@iit.edu
October 26, 2002