2013/03/12

1057	Fed Cricket 4 pellets.
1105	Filled LN2 cold trap full.
1332	Flash detector for 2 hours. Cool down for 1 hours. Take six 5-minute series with Dib 1/2 at +/-6, 4, and 2 V, and then another six 5-minute series with Dib 1/2 at -/+ 6, 4, and 2 V. Between each series there is 6 seconds of flashing, followed by 20 minutes of cool down.
1816	It seems around 1740 that the pressures in G1 and G2 started rising without lowering, and the base temperature is decreasing continuously. We have a blockage. The 5th data file is about to be taken. Perhaps we should wait until it's done to stop the circulation and clean the cold traps.
1830	Closed gate and condenser valves.
	Closed V13A, opened V5.
1833	Opened V12B.
1836	Fed Cricket 4 pellets.
1949	Closed all valves on left hand side of IGH.
2100	Lost track of time so the time stamp isn't correct… stopped 1K pot and stopped He recovery.
	Pulled out He cold trap and began pumping on it.
	Pulled out N2 cold traps. As they warmed, began pumping on them.

Today we attempted to take data at 6 V, 4 V, and 2 V biases, six 5-minute series at each bias. However, the cold traps required cleaning and therefore we had to cut the first bias set, +/- 6 V for Dib 1/2, short by one series and none of the other biases had data taken at them. It was noted right away that only 2 files were taken per series, and each file consisted of 2000 events - this event rate seems unusually low.

We made a comparison below between Am-241 data in Run 32 and Am-241/Pb-210 data in Run 36. We can redo this comparison with a different data set - this Run 32's data set was phonon data at +/- 3 V. perhaps an Am-241-only run close to +/- 6 V in bias, and we can make a timing cut to scale down the number of events to compare to this. See G106a data. In any case, the goal was just to make a quick point that in this Run 36 data set we do believe we are seeing the 60 keV peak from Am-241 and the 40 keV peak from Pb-210. The spectrum in the run 36 data set is slightly shifted to higher values than in normal Am-241 data set- note in Figure 1 and 2 the difference in the position of the bump near 0. We believe that the 60 keV peak in the run 36 data set will be at a slightly higher value than 2 or 3 (1000 a.u.). A look at the spectra from run 32 and 36 in Figure 3 and 4, as well as the zoomed figures 5 and 6, show a standard 60 keV peak from run 32 and a Pb-210 40 keV peak next to a sharp 60 keV peak. Note the broadness of the 40 keV.

The run 32 data shown below has only 2 data sets with 5 minutes of data each. The run 36 data has 5 data sets with 5 minutes of data each. However, it is obvious that there aren't a lot of statistics in the latter data set. We need to increase this to make effective studies of this detector with the Pb-210 source.

Run 32 Analysis (+/- 3 V)	Run 36 Analysis (+/- 6 V)
Figure 1: Qpart, Zip 2 (no cuts)	Figure 2: Qpart, Zip 2 (no cuts)

Figure 3: Qsum, Zip 2 (0.9<Qpart<1.01))	Figure 4: Qsum, Zip 2 (0.95<Qpart<1.01))

Figure 5: Zoom Qsum, Zip 2 (0.9<Qpart<1.01))	Figure 6: Zoom on Qsum, Zip 2 (0.95<Qpart<1.01))