GEn Meeting for October 26, 2005 Attendance: F. Wesselmann, B. Reitz, B. Wojtsekhoski, A. Kolarkar, B. Craver, I. Rachek, E. Chudakov, A. Shahinyan, R. Feuerbach, A. Kelleher, G. Cates, S. Abrahamyan, D. Nikolenko Big Bite Update Detector Update Igor-- concentrated on BB scintillators after adjustment using Eugene's script the amplitudes are mostly in the proper position. very top and bottom hard to fit all peaks at channel 500 1mV per channel (ADC sensitvity) pedestal width = 4-5 channels TDC, 1 channel = 35ps 1ns pulsation, trace to crosstalk fom one pulse to another pulse changing Philips module w/ LeCroy module corrceted this -- Philips Scientific resolution \sigma_{TOF} = 109 ps -- LeCroy resolution \sigma_{TOF} = 90 ps Albert -- install cards when Igor gives first group of goal cards, they will install the cards as they are. Says they are ready to install today. Brandon -- presented plots of first hit per event. Can observe the flat area of drift time with cosmics only. Bodo would like him to look at a group of 16 Electronics Bodo -- Heidi has manuals and is working on cabling all FastBus parts. This will allow us to replace small fastbus. -- Commonstart/common stop? need longer cable for scintillator, need to design schematic for coincidence. for 50ns, can use CAMAC delay, for 100+ns, need to use cables. Igor -- 2nd chamber crosstalk study. Still not happy with status of ringing. 3M connector is not a sufficiently good connecto Upgraded ADC firmware, saw definite improvement. should we update TDCs as well? Neutron Arm Eugene -- showed histrograms from 10cm thick neutron bars. thin bars require additional work, thick bars are nearly done. about 10 modules have pedesta widths of 10 or more channels. after HV is tuned and mapping has been checked, can check left-right coincidence, can already do this with the thick bars. Online -- ADC reported no data after a few events. If one ADC doesn't get its gate it hangs up DAQ Glasgow cables connected to ADC Nov 15 BigBite must be decabled, neutron arm stop operation, decable by November 28, completely decabled by December 15 First detector should be done by next week. Next detector done a few days later. Before the break, Bogdan introduced Dima Nikolenko Milesones Nov 15 -- completion of ND testing Nov 18 -- laser safety review Nov 28 -- first day of down, completion of ND testing, begin decabling. Dec 15 -- full safety review for GEn (include beamline testing with conclusion of rupture tests) -- target motion system working on test bench -- septum off pivot, begin moving neutron arm Jan 2 -- target testing complet, dissassemble target, ready to move Jan 16 -- install Big Bite stand Jan 27 -- operation checkout of polarized target Feb 9 -- Big Bite operational checkout Feb 15 -- target button up Feb 22 -- neutron arm complete with sheilding Feb 24 -- first day of beam Discussion of responsibilities. Gordon will send out memo detailing responsibilities. safety review -- nothing to discuss today software -- longer meeting tomorrow on tracking software, mainly Big Bite. neutron detector class, trying to match with Big HAND map, output has too much redundant information Sergey presented plots of cosmic data target -- Gordon took dou-FAP (dual laser system) to UVA, they tested 3 cells with 3 lasers (using 1/2 the light), polarization results: Dexter = 52%, Al, the target cell = 53.7%, Barbara = 53%. 4 of 4 cells tested with high laser power have exceeded 50%, so we can assume we 50% polarization for run plan. think that they overheated a polarizing cube at UVa. stopped production of 20:1 K to Rb mixture and started production of 5:1 mixutre, will make 4 cells with new mixture (between UVA and William & Mary). Highest recorded polarization of hybrid comes from 1:1 mixture (under different circumstances). Bogdan reports that the beam window for the beam dump side of the beamline will be 16mil Be. this indicates that we will need heavy shielding. design -- target support tube and target ladder have been ordered and should arrive November 23. Alan has been waiting for a week for an answer on the laser enclosure. He needs to know if we need additional cooling for the optics. Gordon says yes, because of the overheated polarizing cube.. Joyce is finishing support for the target drive. Should be in before thanksgiving. List of outstanding design work -- mount optics and drive on target system -- laser system not on critical path, but should be ready mid-next week (part needs to be sent out for annodizing) -- still hasn't done work on compass mount Gordon will talk to Alan about design for instrumentation. Bogdan's concerns: compass design angle measurement of electron beam