From bfleming@phys.columbia.edu Wed Apr 25 11:22:54 2001 Date: Wed, 25 Apr 2001 11:01:46 -0400 (EDT) From: "Bonnie T. Fleming" To: johna@anl.gov, hal@anl.gov, holt@anl.gov, geesaman@anl.gov, olness@pascal.physics.smu.edu, gallag@hep.umn.edu, ukyang@hecate.fnal.gov, rex@iucf.indiana.edu, jorge@fnal.gov, reimer@anl.gov, potterveld@anl.gov, charlie@iucf.indiana.edu, wmelnitc@physics.adelaide.edu.au Subject: Minutes for Non-oscillation physics group for the Proton driver study -- meeting on April 4th and April 17th MINUTES: 4 APRIL 2001 Hello Working Group, Following are the minutes from our April 4th working group meeting. Following that are the minutes from the April 17th working group meeting....sorry for the delay!!! Ana Pla and Dave Anderson from the MINOs group joined the first part of our meeting to discuss the scintillator design for the MINOs detector planes as well as R&D they've been working on for future work with this type of design. The MINOs detector uses extruded plastic scintillator read out by wavelength shifting fibers coupled to photodetectors. The scintillator strips are 1cm thick and 4.1 cm wide. Each is co-extruded with a titanium dioxide outer layer for reflectivity and a groove for the wavelenth shifting fiber. More information on the scintillator planes in the MINOs detector can be found in chapter five of the MINOs TDR: http://www-numi.fnal.gov:8875/minwork/info/minos_tdr.html. Ana and Dave have been working on an improved design for this type of scintillator detector component. This design employs scintillator planes that are 10cm wide and 1cm thick with 10 holes in it for readout fibers every 1cm. These are stacked in x and y to get position resolutions of a few mm. The material used is C_8H_8 polystyrene coated with titanium dioxide like the MINOs design. Light output is expected to be ~12-15 PE's on PMTs placed at the end of a few meters of fiber. The challenge is to make a detector as fine grained in resolution as possible. At this point, fibers located 1cm apart is as close as can reasonably be designed. This design will be tested soon but testing beyond this will not be conducted until there is more interest in the design. Approximate cost of 1 ton of these scintillator planes is about 10,000 USD. Dave Potterveld has been working on GEANT simulations of a scintillator detector. He is usng a sample of neutrinos at the center of the detector. Jorge is rerunning code to have a new sample of events across the face of the near detector for Dave and others to work with. nu-e elastic measurements were discussed. Specifically, what is necessary to make a good measurement. what maximum Q^2 is needed, and what transverse area is needed to reconstruct events. How low in proton energy can we go? To 250-500MeV? BNL 734 measured the NC/CC ratio to 11%. Error was predominately systematic. Premliniary work from Rex and Chuck indicate that we need to measure the NC/CC ratio to 5% in order to have good sensitivity to strange quark content. This would give an error on delta_S to 0.04% which is competitive with DIS measurements. BNL 734 used scintillator bars interspersed with DCs. What kind of granularity did they have? Other possible problems they had include neutron capture problems and difficulty rejecting multitrack events. Rex and Chuck will write something up including specific numbers on what we could expect as well as beginning some kinematic and MC studies. Discussion of what topics the group is most interested in pursing followed. These include d/u ratio at high x, nuclear effect measurements for neutrinos specifically shadowing effects at small x and differences in nuclear effects for valence and sea quarks. Intrinsic heavy quark effects were also discussed. Detector designs including pure hydrogen or deuterium vs. carbon vs bubble chambers were discussed. All designs are still on the table. Thanks! Bonnie