Minutes from weekly target meeting held 16th of August 2002 in building 888 a) The upstream EIO tube was broken after 15 years of service on Friday morning. Different possibilities are looked at: use Nagoya high power EIO tube with its PSU, polarise only one target half at a time or use carcinotron source. Problem with Nagoya EIO tube microwave generator is the high power up to 30 W and missing frequency modulation possibility. Information from Tapio: Varian can probably repair the broken tube with cost less than a new one, steel wave guide could be used to reduce the power from the EIO tube, the EIO cathode voltage is used mainly to tune the frequency and the anode voltage the power, the FM possibility was implemented with capacitive coupling of modulate HV source to the anode. Satish Dhawan and Don Crabb were contacted to find out where the SMC spare tube is now. Norihiro promised to contact Varian to get latest information about price for a new EIO tube. b) Jacques estimated the relaxation times in the transverse spin mode to be 1900 h for negative polarisation and 2100 h for positive polarisation at 0.42 T. c) Planning for following weeks: on the machine development of Wednesday 21st and 28th August EPR-line measurements with the Bochum IMPATT diode microwave source. On same days checking of NMR signals of 6Li, 7Li, 3He and proton (half of the target material is 6Li with 5 % of 7Li!). The EST check takes 2 - 3 hours. d) Yuri suggested disconnecting one of the RF excitations to one of the Q-meters during MD to see if there is influence to the polarisation measurement. Kaori commented that we should do this kind of technical tests after the beam time. Jaakko said that we already tried to disconnect the excitation going to the NMR coil, but still feeding the modulator to see the signal coupling from neighbour coils. Yuri said that we must get a vector voltmeter for tuning of the coils. Yuri pointed out that the main problem for the exact polarisation calibration is the transition from dilution mode to pure 4He mode since the speer resistor values change. e) Kaori tried to use the negative field TE-calibration data to correct the polarisation results seen in negative field. This yielded a smaller spread than seen now when using only the positive field TE-calibration data. The remaining spread can be due to retuning of the Q-meters with Gerhard after the first TE-calibration was done. f) Jaakko fitted the deuterium NMR-data of coil #3 both in positive and negative fields to the memory function at high average negative polarisation of - 48 %. The dispersion of the signal was corrected with the help of Kramers-Kronig relation and phase to get symmetric absorption signal. In positive field only small phase correction is necessary and fitting works well giving 2nd and 4th moments of 2.8e+6 Hz^2 and 4e+13 Hz^4. In negative field case phase shift of +0.15 rad is necessary, but the lineshape fits still satisfactorily. Thus the NMR-signals look ok except for field direction dependent scaling factor. Simple phase shift does not explain the difference between negative and positive field directions (phase correction gives about 1 % or less in the integrated area). Thus probably the RF-excitation is redistributed between the coils, while the total RF-energy in the system stays the same. Yuri suggested that there could be an "elliptic" (or otherwise unsymmetric) RF-field. At positive field the spins feel different RF-field from negative field. The situation resembles the crossed coil configuration in the early SMC times. g) Yuri expressed his worry about 5th roots blower #10, which has 5 C higher motor coil temperature than the 40 C before. Also there is extra noise coming from this pump. Jaakko said that usually the problem is the cooling fan. There is a spare roots blower for #10 in the pump room, which has also a cooling fan that can be used to replace the one on the pump if needed. Kenneth said that the higher temperature can be due to higher ambient temperature in the pump room.