Table of Contents
2011/04/28
| 0040 | Flash detector overnight: LED 1 on both DIBs; 0.6 mA; 100 μs on, 2.5 ms off. |
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| Fill N2 cold trap full. | |
| 1230 | Stop flashing detector. |
| 1330 | Try DAQ code again. Version 3 seems to work in so far as collecting random triggers. It still stops after taking random traces. Not sure what we did that was so different from yesterday. |
| Fill N2 cold trap full. | |
| Flash detector: LED 1 on both DIBs; 0.6 mA; 100 μs on, 2.5 ms off. | |
| 1400 | Stop flashing detector. |
SQUID Tuning
| 1630 | Tune SQUIDs. |
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| Triangle wave of amplitude 300 mV used. Larger than what we normally use in an effort to see full modulation curves. Anything larger than this results exceeds the DAQ's dynamic range, and thus results in saturation. | |
| The displayed trace of the triangle wave has an approximately factor of 6 larger amplitude than our input signal. Not sure why this is, however from looking at the modulation curves, a 300 mV input signal behaves like a 300 mV input singal in that just over 1 full modulation curve is witnessed. | |
| Gain of 100 between the SQUID array and displayed trace needs to be taken into account when looking at the modulation curves below. This gain is factored out of the values for Modulation Depths in Tables 1 & 2. | |
| Changing the 600 mK and 4 K stages to brass screws only has improved the modulation curves significantly! |
| Table 1: Settings for SQUET Card ZC70 | |||
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| Phonon Channel | SQUID bias [μA] | Lockpoint [mV] | Modulation Depth [mV] |
| A | 85 | 4.2 | 4.9 |
| B | 72 | 4.0 | 4.7 |
| C | 84 | 3.5 | 4.3 |
| D | 88 | 2.6 | 4.9 |
| Figure 1: Triangle Wave, Modulation Curves & Derivative for SQUID A SQUET card ZC70 |
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| Figure 2: Triangle Wave, Modulation Curves & Derivative for SQUID B SQUET card ZC70 |
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| Figure 3: Triangle Wave, Modulation Curves & Derivative for SQUID C SQUET card ZC70 |
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| Figure 4: Triangle Wave, Modulation Curves & Derivative for SQUID D SQUET card ZC70 |
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| Table 2: SQUET Card ZC23 | |||
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| Phonon Channel | SQUID bias [μA] | Lockpoint [mV] | Modulation Depth [mV] |
| A | 96 | 4.4 | 5.7 |
| B | 98 | 3.2 | 5.5 |
| C | 98 | 5.8 | 5.4 |
| D | 94 | 4.1 | 5.3 |
| Figure 5: Triangle Wave, Modulation Curves & Derivative for SQUID A SQUET card ZC23 |
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| Figure 6: Triangle Wave, Modulation Curves & Derivative for SQUID B SQUET card ZC23 |
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| Figure 7: Triangle Wave, Modulation Curves & Derivative for SQUID C SQUET card ZC23 |
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| Figure 8: Triangle Wave, Modulation Curves & Derivative for SQUID D SQUET card ZC23 |
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| 1945 | Start taking data with old DAQ; series: 07110428_1946. SQUIDs locked, but no QET bias. DCRC30 plugged into DIB1, -2 V bias. DCRC33 plugged into DIB2, +2 V bias. One phonon channel on DIB1 has railed. This is a short run to look at neutralisation. |
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| 2100 | Fill N2 cold trap full. |
| 2110 | Stop taking data on file 14. |
| Flash detector overnight: LED 1 on both DIBs; 0.6 mA; 100 μs on, 2.5 ms off. |