Minutes from target meeting held March 9 2012 in 892-2-009 These minutes are available also from: http://wwwcompass.cern.ch/compass/detector/target/Minutes/2012/ a) Jaakko: new program 'syscurie' to estimate systematic error in the Curie constants from the systematic error in the integrated areas and from the temperature. See https://svnweb.cern.ch/trac/ptnmr b) Jaakko: calculate Curie constant systematic errors 2010 from the integrated areas and temperatures. The systematic error is typically 2 - 4 % for each coil except for coil #1 where it is much larger. See http://wwwcompass.cern.ch/elog/target_polar/174 c) Other systematic effects in the polarization measurement were discussed. The NMR-signal stability is very good and there is no evidence of coupling of the NMR circuit to the resistive thermometers, which could explain some of the errors reported in NIMA 437 p. 23-67. From the 2011 NMR-frequency shift vs. polarization plots no significant saturation or non-linearity is expected (see http://wwwcompass.cern.ch/elog/target_polar/139). The protons in the target holder construction materials could also reach slowly 1 - 5 % polarization due to low temperature. However this effect is not visible in the measured NMR-signals when the microwaves are stopped and frozen spin mode is started. d) Kaori: recalculate the Curie constants 2010 now with the same temperature values and errors like Jaakko. The 1.4 K empty cell calibration period after the run where the helium-3 pumping line gate valve was closed was eliminated from the data set. Very good agreement with Jaakko's data, see http://wwwcompass.cern.ch/elog/target_polar/176 e) Yuri: helium-3 could also be polarized. The data from 2001 suggests however that this polarization is small up to 0.5 %. See http://wwwcompass.cern.ch/elog/target_polar/66 f) Yuri: check 2010 target material data calculation. Good agreement with the report in elog http://wwwcompass.cern.ch/elog/target_polar/127 g) Fabrice: contact CERN workshop to discuss rebuilding Pfeiffer helium-3 roots blowers water cooled heat exchangers. Produce drawing of the new diffusion pump control panel. h) Yuri: for the Drell-Yan hadron beam it is better to have a microwave cavity that can keep the helium-3 inside in case that the glassfiber-epoxy mixing chamber is damaged in the beam.