Minutes of the MuCool metting, Aug 11 1998, 11:00 A.M. - 12:30 P.M. The meeting was held in the 10th Phys. Conf. room. Present, at Fermilab : Dave carey, Ray Stefanski, Steve Geer, Alvin Tollestrup, Dave Finley, Tom Kobilarcik, Panagiotis Spentzrouris, yuri P.Paul Lebrun. Over phone lines, Steve Kahn (BNL) and Ed Black (IIT). Secretary is Paul Lebrun. I. Li Lens simulation status. (P. Spentzrouris.) Panagiotis gave a status report on the simulation of a cooling channels based on multiple Li Lenses (two for now). One has to come with beam transport that matches the optics of the Li lens, and can accomodate the r.f. system. Two solutions comes to mind, one base on the use of Solenoidal fields to match the beam out of the first Li lens into the second one. The second configuration could be based on use of more conventional beam optics, based on quadupoles, sextupoles and so forth, as proposed by Valery Balbekov. Panagiotis showed that matching in and out of Li Lens is achievable with inhomogeous solenoids. At least, he is moving rapidly towards an acceptable solution. The Li lens are 1 m. long, Surface field is 10 Tesla. The matching solenoids is approximately 2.5 m. long, and has high field at both ends. Chromatic corrections can be made by adding current loops at the end of the solenoid, and by moving the focal point a bit upstream. The radius at low beta is 12 cm, the field is 2 Tesla. Note that the solenoidal field extends into the drift region separating the solenoid from the Li lens, e.g., there are no field free region in this system. The normalized 2D transverse emittance decreases after the first lens, showing cooling, than apparently increases as the beam enter the matching solenoid. This is because the angular momentum the beam acquires has not been subtracted. Due the almost perfect matching, the emittance decreases again to the level reached exiting the firt Li Lens, and decreases again as it exits the seconf Li Lens, demonstrating transverse cooling with two Li lens. Panagiotis showed more detailed distributions (X vs Px,..), showing that the chromatic correction could be improved. That is, the fringe field at the end of the solenoidal matching can be optimized better. In addition, the longitudinal field currently reaches 40 Tesla, probably unphysically large and not really needed. Once this tuning is done, Panagiotis will work on two distinct front: (i) include realistic r.f. in the 2.5 m. long matching solenoid, (ii) attempt at building a similar beam transport with Quadrupoles, with the help of Valery B. II. D2 limitation and other option for the MUCOOL beam line. R. Stefanski. Ray presented some option to replace or "baseline" beam line, the D2 beam line from Brookhaven, with an other beam line. The limitation of this D2 beam line are: - Limited flux: we could use more muons. - Pion contamination at higher momentum (260 MeV/c) is substantial, definitly larger than 1 %. - The matching to the bent solenoid is not obvious, and could be costly. Therefore Ray presented some preliminary investigation on other options: 1. The LANL beam line. This optionwas rejected in the past because the beam line does not fit into the Meson area. It is also unclear how we could collect pions produced by 120 GeV/c proton beam in this beam line. The flux at LANL (10^5 muon- per 10^13 ppp) is higher than our current estimate of D2 installed at Meson West. However, we have no estimate yet how the LANL beam line would perform with 120 GeV/c proton beam. 2. The idea of the pion Circulator, e.g., having a low energy ring, where the pions decay. More detailed desing work needs to be done to asses cost and feasibility. May be we should work on it. 3. Our Muon Collider Target and Pion collection/Phase rotation experiment could be extended with a pion decay channel, based on solenoids. At the end of this discussion, it was suggested we try to improve the D2 beam line once again, by improving the yield at the entrance of the decay channel, by varying the target angle. We could collect more forward pion, and relax a bit on the beam purity, but increases the flux. IV Steve Kahn briefly reported on progress in the Geant 3 simulation of the downtream end of the D2 beam line, and the matching into the bent solenoid. He now has 90% efficiency. Steve will now study the wedge, to correct for dispaersion. V. Steve Geer reported on his trip to Washington, where he met with NSF and DOE representatives. Steve was accompanied by Bob Palmer, Andy Sessler and Kirk McDonald. The topic was budget for FY99. At NSF, they gave full support to the proposals put forward by our collaborator from Indiana: Scott Berg wants to study the muon accelration and Gail Hanson want to work on the cooling exchange and bent solenoids. They also express support for (and confidence) that NSF people will work with DOE to provide adequate funding. The primary reason of the trip was to present to high level HEP DOE people (John O'Fallon, Peter Rosen, D. Sutter,..) our ~ $4 million request. (the laundry list will be placed on our web page, see details there). Bob Palmer gave the overview talk, Steve presented MuCool and Kirk presented the target experiment. These presentation were useful, as DOE now understands that a limited funding of one million dollar will be not be enough to sustain a credible Muon Collider R&D program next year. Steve Geer is confident that, although receiving the full $4 million is probably optimistic, DOE now appreciated that we need more than one million.