Minutes from weekly target meeting held 23th of November 2001 in 892 a) In helium inventory 1404 l of NTP 3He gas and 9033 l NTP 4He gas was found. The change is +1.2 % of 3He compared to the inventory of last March and + 20.3 % of 4He. b) Leak testing of possible leaks from the cryostat evaporator to the 3He circulation was done. The dilution cryostat was pumped empty and evaporator filled with LHe. During one day of continuous evaporator operation the still pressure stayed very low (2*10^-2 mbar), while the mixing chamber was around 50 - 60 K. Thus there is no indication of leak from evaporator to the dilution cryostat. c) Moving of the target magnet before and after field rotation was checked. The rotation was 0.3 mrad and moving along beam axis 0.1 mm. Naoki wrote a COMPASS note 2001-14 about the tests. d) The target material was unloaded successfully on Thursday. It was stored into LN2 dewar in the pump room. Small amount was transported to Bochum for tests. e) For the next year we propose a separate target shift from DAQ shift. One person is needed for the shift. Each week there is a "weekly target coordinator". The night shifts from 00:00 to 08:00 are done by the target experts, while for the shifts 08:00 - 16:00 and 16:00 - 24:00 we should get people from collaboration. The details are going to be discussed with the run coordinator. Training for the target shifts needs to be organised. f) Integration of target to DCS. We have to gather what parameters should be measured. For example in pump room: roots #1, #20, #23 status on/off, VHB open/closed, roots temperatures, pump room temperature, evaporator pumps on/off, roots back pressure, cooling water pressure, still pressure. On platform pumping and screen line temperatures, magnet current lead and screen temperatures, hall probes for magnetic field, isolation vacuum. The most critical "external" parameters should be included, but not the "internal" ones like mixing chamber temperature. g) Vadim made calculations on the influence of reduction of TH diameter to the beam halo. This is due to steel flanges, which are closer to the beam than in the present 70 mm mixing chamber case. Both 44 mm and 50 mm mixing chamber cases were studied. Number of hits to DC02X increased from 9.7 % to 10.0 % (between "nothing" and 44 mm case) and to MM01X from 22.2 % to 22.9%. Trigger is not influenced much. This and minimisation of target material will be discussed with Vadim and Jean-Marc. h) THs for 2002 were discussed. First we should start to test the NMR coils. We should prepare first TH with large diameter and later TH with smaller diameter. To remove the dead volume (present in run 2001) of 10 cm long at the down stream end of the target there are two options. One is to shift the target cells down stream by 10 cm. The second is to make the mixing chamber shorter. In this case we will loose the possibility to move the cells down stream. Moving of target cells means that we have to manufacture extension piece to upstream end of microwave cavity, extensions to microwave guides and probably a new longer Kevlar tube. Acceptance will also improve a little. i) Cooling down of the target should start about one month before the beam time to make sure that everything is ok when the beam is on. Detailed planning needs to be done. j) Check/refurbish SMC solenoid PSU and buy spare trim PSU. These were first put to use in -93 and should be checked for proper operation. There was discussion whether the Drusch PSU for solenoid needs to be refurbished or not. If it fails during beam time it is possible to use temporarily dipole PSU. Complete refurbishment is estimated to cost about 20 000 Euro (same as for the dipole PSU). k) Discussion about TE-calibration data analysis mostly done by Kaori. The gain calibration between normal polarisation measurement (gain = 1) and TE-calibration (gain about 200) was discussed. Integration of Q-curve and checking gain at each point of the Q-curve give slightly different results. Jaakko pointed out that the baseline or Q-curve is the only calibration signal available to check stability of the Q-meter. There is systematic dependence of the Q-curve on magnetic field (e.g. f_0 = 16.4032 MHz -> 16.3913 MHz and Q = 16.26 -> 14.29 when field is increased from low value 0.5 T to 2.5 T). Before and after field rotation, i.e. either at positive or negative fields, no such systematic change is seen. Anyway the Q-curves should be used to check the stability of the Q-meters during the run. The gain calibration could be done after each new Q-curve.