Minutes of FT Upgrade Meeting held on 29/10/98 at Daresbury. ============================================================ Present: Steve Burke, Tim Greenshaw, Rob Henderson, Derrick Hill, Graham Houghton, Jim Kay, Girish Patel, Dave Sankey, Terry Sloan, Graham Stokes. 1) Actions from meeting on 17/9/98. ----------------------------------- a) Tim described the situation w.r.t. the support of the magnet to be placed within the front section of H1. This, originally called QO, has been renamed GO. The upshot of a simple "lever" model of the cryostat is that it appears impossible to get GO through the neck of the LAr cryostat with both H1 and HERA on the nominal beam axis. Finite Element Analysis of the cryostat (done at Saclay) shows that the upgrade does not produce unacceptable strains at any point of the cryostat, regardless of how GO is supported. Action. (Tim) Clarify support situation with Karsten Gadow at DESY. b) Graham H showed the updated overall project schedule and the schedule for the shutdown work at DESY. Graham also described developments on the construction of the circular PCBs. The artwork is complete and CAD files have been successfully transferred to the firm doing the etching. Test pieces were due to arrive the day after the meeting. Graham told us that a clean-room (tent) is to arrive from SLAC around Christmas and showed us how this could fit into the available space. Action. (Graham) Modify schedules to include latest information. (Graham) Study test pieces. (Graham) Start preparation of space for tent. c) Tim described the HV tests done on a piece of the 0.5mm FR4 (PCB) with 12 mu copper by John Morton. There was no indication of breakdown through the board; sparking occurred across 5mm gaps between electrodes at +/- HV and earth. d) Jim explained that the preference is to make one planar wall of 10mm Nomex (the wall attached to the U channel of the gas tank) the other of 3 mm Nomex. This gives the necessary space for cabling within the tank without compromising mechanical stability. The decision was taken to build the chambers with one 10mm and one 3mm wall. e) Derrick stated that Claire thought the 10mm walls of the FPCs were only necessary to provide mechanical strength for the FPCs, and not as a structural element of the tank. f) Tim passed on the information from Don that the Planars should be tested in Ar:CO2 90:10. It was asked whether the gas should be bubbled through methanol, necessitating the use of a 'fridge. Action. (Tim) Inquire about necessity of using methanol. (Tim/Derrick) Locate flow meters. g) Jim told us that three crimp tools are being manufactured. Three are considered necessary as they tend to suffer from wear. He also explained how the wires are inserted into the chambers. This is done after the contruction of the cell structures with the help of a support structure onto which the Nomex end pieces and the wires are first attached. (This requires soldering and is a further reason for gold-plating the tungsten wires; they are then more amenable to this process!) The Nomex blocks are then fastened in position using dowels and the final tensioning done. The procedure is simplified by having a hole in the centre of the table on which the wiring is done. h) Derrick described the situation w.r.t. the Medelec pins. Medelec have answered a fax at last and are sending some sample pins. These are a new design. There is a copper inner section with a brass sleeve onto which is shrunk fit a stainless steel collar. Action. (Derrick) Test pins to ensure no slippage when wire inserted and tensioned. i) Derrick described progress with setting up the Planar test system. Scintillators are being prepared, a CAEN HV supply is available, fan-outs are to be constructed and NIM electronics is available as is current monitoring equipment. It was suggested that a QVT would be a useful addition to the test equipment. Derrick and Dave explained that they have located the software necessary for the pre-amp tests, but have not yet been able to check that all functions as required. The pre-amps are out for tender. Action. (Derrick) Continue preparation of test equipment. (Dave) Test pre-amp test software. (Tim) Manchester personnel available for tests? j) Jim descibed the Noryl end piece design. These can be constructed by Dave Stanley at RAL. k) See Steve Burke's results below. l) Girish explained that he was in the process of getting the necessary software running at RAL. Action. (Girish) FTREC results with 4 wires per Radial off/Radial in SM2 removed. m) Rob went through the arguments on the optimal orientation of the new Planar. The wires should be at 90 deg to those in the preceding (old) Planar. To recap. looking from interaction point the orientation of the Planars is as follows: Planar 0, wires vertical. PLanar 1, wires at 60 deg clockwise from vertical. Planar 2, wires at 60 deg anti-clockwise from vertical. Planar 3 (the new planar) 30 deg from vertical clockwise. n) Tim explained that he had yet to locate the drawings of the front field formers. Action. (Tim) Find drawings of front field former assembly. o) No results from the FIT were presented. Action. (Don) Results from FIT running 1998. p) Derrick told us that three Hamamatsu hybrid photo-diodes are now available for tests (cost £500 each). These have a gain of about 1000 to 1500 and require an HV supply of about 6..7 kV. q) Girish explained that Mike has produced a GEANT version of the FT with new 4 wire Planars and that Steve has added new hit generation routines. r) Tim explained that there has been no change in the manpower situation for software development (in particular Planar chamber monitoring). Action. (Tim) Find new manpower for FT software. 2) High Q^2 simulations of FT with additional material. ------------------------------------------------------- Steve Burke explained his studies of the FT with: a) The hub converted to lead (equivalent ~5mm steel). b) The beampipe converted to lead (equivalent to ~5mm steel). The results in both cases were similar. The number of additional vertices within the FT at small radius (120 < z < 250 cm and 4 < r < 15 cm) increased from 2.9 to 6.8. These vertices were nearly all the result of pair production and the tracks produced had momenta of ~100 MeV. Action. (Steve and Girish) Look at high Q^2 events with/without GO. 3) Radial chambers in 1998. --------------------------- Girish commented on the behaviour of the Radial chambers in this year's running. These have tended to be less stable than in previous years and, although this may be attributable to bad beam conditions, it may also be the first indication of damage caused to the chambers because of the total amount of charge they have seen. We must also remember that beam conditions may be permanently "bad" after the HERA upgrade. Action. (Girish) Continue monitoring of performance of Radials. 4) Construction of additional planar chambers. ---------------------------------------------- The possibility of constructing additional planar chambers for the eventuality that the Radials cease to function was discussed. It was suggested that we consider ordering an additional 2 sets of PCBs to allow construction of two additional Planars. Action. (Tim/John) Check finances to see if can afford additional PCBs. 5) Simulation status and outstanding problems. ---------------------------------------------- Girish explained that he is in the process of getting the simulation running at RAL. The new FT has been incorporated by Mike and Girish (with all Radials in the FT and no simulation of the forward trigger). The hit production has also been done by Steve. The magnet is not yet in the simulation, however. Action. (Girish) Get simulation running at RAL. (Girish) Pass modifications onto H1SIM librarian. (Girish) Get magnet simulation from Klaus Wacker. 6) Dates of next meetings. -------------------------- The next meetings will be as follows: 26/10/1998 11:00...16:00 Daresbury. 10/12/1998. 28/01/1999. Action for next meeting on: Clarification of magnet support situation (Tim). Modify schedules (Graham H). Study test PCBs (Graham). Start preparation of space for tent (Graham). Inquire about necessity of using methanol in test gas (Tim). Locate flow meters (Tim/Derrick). Test pins to ensure no slippage when wire inserted and tensioned (Derrick). Continue preparation of test equipment (Derrick). Test pre-amp test software (Dave). Find out if Manchester personnel available for tests (Tim). FTREC results with 4 wires per Radial off/Radial in SM2 removed (Girish). Find drawings of front field former assembly (Tim). Results from FIT running 1998 (Don). Find new manpower for FT software (Tim). Look at high Q^2 events with/without GO (Steve and Girish). Continue monitoring of performance of Radials (Girish). Check finances to see if can afford additional PCBs (Tim). Get simulation running at RAL (Girish). Pass FT simulation modifications onto H1SIM librarian (Girish). Get magnet simulation from Klaus Wacker (Girish).