Minutes from target meeting held June 4 2010 in 892-1-B09 These minutes are available also from: http://wwwcompass.cern.ch/compass/detector/target/Minutes/2010/ a) During polarization build up on Friday evening around 23:22 general power failure at CERN on May 28. Helium-3 roots powered from diesel network still running, but helium-4 and isolation vacuum pumps stopped. Start to remove helium-3 00:30. Bypass helium-4 pumps. Transfer of LHe from buffer dewar to dilution cryostat recovered. UPS network still operational in pump room but missing from platform (the circuit breakers in 891, door locked). Power recovered 1:30-2:00, but Ethernet down due to missing power from UPS network. Two new power cuts at 7:39, 7:45 and 12:30. No access with Ethernet from outside to check status of helium-4 pumps or magnet cryogenics before around 10:00, when the network switch was recovered. b) Demineralized water lost and the valves to the magnet power supplies were closed. Later the water recovered and produced slight over pressure in the cooling pipes of transistor banks. Some water dropped on the isolation vacuum pump PLC. The isolation vacuum pumps not operational due to PLC staying in stop mode. On Monday contact Alcatel for possible intervention. On Tuesday leak test again isolation vacuum with leak detector. Background leak level below 10^-9 mbar l/s, so the vacuum pumps are not really needed for target operation. The diffusion pump finally restarted on Wednesday, probably humidity evaporated from PLC. c) Tuesday test the backup pump system powered by 48 VDC network. The rotary pump working, but the current to the turbo pump too high. Maybe cable problem. Use 230 VAC rotary pump and turbo control unit. Open the second vacuum port gate valve for pumping and run the turbo pumping system. No change in isolation vacuum pressure, which stayed at 5 10^-8 mbar during the tests (the cryopumping much more efficient than mechanical pumps). d) Update Wiki notes http://wwwcompass.cern.ch/twiki/bin/view/PolarizedTarget/PolTargHe4PumpStart http://wwwcompass.cern.ch/twiki/bin/view/PolarizedTarget/PolTargPower e) Condense helium-3/4 mixture on Wednesday. In afternoon temperatures below 100 mK reached. Remove helium-3 from circulation on Thursday. The cooling water flow switch for security failed to close. The water filter already dirty and restricting the flow. Clean and remount. The normal flow recovered. f) Fabrice: resync time in PVSS and helium-4 pump PLC. Increase the helium-4 roots speed. Slower start up 60 s (was 10 s) for the roots. First the roots stay at 25 % pumping speed for 30 s. g) Fabrice: magnet safety system (MSS) default can not be reset. The quench detection system failure maybe due to the several power cuts. h) Yuri: calculate NMR-line asymmetries. i) Kaori: connection from NMR PC to run logbook MySQL server working now. Thus the polarization data visible from run logbook. j) Jaakko: test AVS-47 (Yamagata) in office. Operation seems normal. This model of preamplifier does not allow to change grounding configuration, which could be the reason for heating the other thermometers in the target holder.