2013/09/05

0500	Mixing chamber temperature 7.9 K and rising slowly. Dump pressure 840 mbar: I think we have reached the point at which we are forced to evacuate the mixing chamber lines to atmosphere. Trouble is, I'm not sure the 1 K pot pump can cope at these temperatures. Decided against using the turbo pump as the valves on the IGH are not designed for it. Isolate dump by closing manual valves, and close all possible paths on IGH (valves V5, V6 & V9). Cease pumping on nitrogen cold trap 2. Commence pumping on mixing chamber with 1 K pot pump from both sides: via valves V2 & V1 for condenser line and valves V for pumping line.
	Turn on mixing chamber heater, power 20 mW, to warm up fridge as quickly as possible.
0510	Fill N2 cold trap full to prevent contamination in nitrogen cold trap 1 warming up and triggering pressure relief valve.
0515	Pressure in He-3 pump exhaust has risen from 840 mbar to 862 mbar since dump was isolated. It appears to have stabilised. I don't think this is anything to worry about.

Charge Collection Efficiency

Figure 1: Charge Collection Efficiency on Side 2 as a function of bias for G106a.

Table 1: 60 keV Peak Positions on Side 2 for G106a.
Side 2 Bias [V]	Mean [mV]	Sigma [mV]
-12	(2.207 ± 0.004) E-3	(5.524 ± 0.425) E-5
-4.5	(2.091 ± 0.002) E-3	(4.921 ± 0.237) E-5
-4	(2.062 ± 0.002) E-3	(3.367 ± 0.160) E-5
-3.5	(2.042 ± 0.002) E-3	(3.793 ± 0.182) E-5
-3	(2.044 ± 0.002) E-3	(3.834 ± 0.178) E-5
-2	(2.012 ± 0.002) E-3	(3.871 ± 0.178) E-5
-1	(1.835 ± 0.005) E-3	(8.964 ± 0.364) E-5
+2	(1.542 ± 0.010) E-3	(9.762 ± 0.803) E-5
+3	(1.760 ± 0.004) E-3	(4.987 ± 0.328) E-5
+3.5	(1.804 ± 0.003) E-3	(3.039 ± 0.210) E-5
+4	(1.845 ± 0.003) E-3	(4.687 ± 0.313) E-5
+4.5	(1.860 ± 0.003) E-3	(4.468 ± 0.258) E-5
+12	(2.111 ± 0.003) E-3	(6.147 ± 0.282) E-5