Run diary
11/20/2009 9:47:27 AM
MC temperature fluctuates.
11/20/2009 2:28:02 PM
Take data set Run001 to Run003
Can see the same noise peaks in the psd taken by the scope at the feedback line.
11/20/2009 2:57:50 PM
Fill N2 cold trap full.
11/20/2009 3:34:45 PM
Take traces Run004 and Run005
Compare spectrum at QET bias line and the DCRC. It seems the input line is already contaminated by noise.
11/20/2009 4:00:02 PM
Set QETb bias to 1480 uA to drive it normal and compare the noise at the input and output sides.
11/20/2009 4:13:37 PM
Take psd run006 and run007
compare psd at normal sate
11/20/2009 4:22:33 PM
Set QETB=0. When QETB=1480 uA, oscilloscope DC voltage = 20.4 mV.
11/20/2009 5:27:05 PM
Compare AC and DC methods of measuring the Ic at a given temperature. Send a triangle wave down the QET biasing line, monitor both the QET bias and the feedback line.
At T = (36.75 +/- 0.25) mK, 57 Hz the Ic's are:
85 mVpp + 0 mVDC or 10 mVpp + 17 mVDC (10mVpp is the smallest signal that can show up in the scope in this measurement)
There is quite a difference between two different methods. This could be an AC effect or temperature effect or both.
11/20/2009 6:38:48 PM
Fill N2 cold trap full.
Data list
Psd
| Time | Run # | MC T (mK) | Channel | FB Gain | Output Gain | SQUID Bias (uA) | Lock Point (mV) | QET Bias (uA) | Qi Bias (V) | Qo Bias (V) | Comment |
| 11/20/2009 2:32:08 PM | 1 | 34.5 | B | 7 | 1 | 95 | 3.4 | 0 | 0 | 0 | TES SC, Fridge grounded to Orange ground. Scope monitor FB |
| 2 | 34.5 | B | 7 | 1 | 95 | 3.4 | 0 | 0 | 0 | Scope PSD | |
| 3 | 34.5 | B | 7 | 1 | 95 | 3.4 | 0 | 0 | 0 | DCRC PSD with Scope by battery. The inputs of scope are actually ioslated. | |
| 11/20/2009 3:30:39 PM | 4 | 35.4 | B | Scope, QET bias | |||||||
| 11/20/2009 3:34:00 PM | 5 | 35.4 | B | DCRC | |||||||
| 11/20/2009 4:14:33 PM | 6 | 1480 | DCRC | ||||||||
| 7 | 1480 | Scope, QET bias |