2013/02/16
| 1140 | Filled LN2 cold trap. |
|---|---|
| Fed Cricket 4 pellets. | |
| 1207 | Plugged in DCRC31 and attached shields. Plugged in power cords. |
| 1218 | Begin zapping SQUIDs. |
| Just remembered that it would have been good to do an electrical check first. Oh well. If dib 1 still looks really awful, I'll remove the board and do an electrical check. | |
| 1249 | Signals are a slight improvement from yesterday. However, there is still a lot of noise. Going to attempt more shielding. |
| 1350 | Aluminum foil shielding didn't help. In the midst of electrical check now. |
| 1400 | Electrical check complete. Nothing outstanding to suggest a cause for the noise. |
| 1500 | Plugged DCRC 31 back in and re-powered it. Now zapping SQUIDs. |
| 1550 | The pulses are looking a lot clearer. However, D3 still seems to be a noisier channel. Going to make thorough rounds to observe each channel, and see if I can lower the QET biases to original QET settings (IbIs-determined). Currently seeing some saturation. |
| 1649 | Currently making a table looking at Dib 3. However, noise behavior is not consistent, so it's hard to make any solid conclusions. |
| Wary of increasing ADC bin number because more saturated pulses trigger. | |
| 1659 | Dib 2 seems okay. A little noisy but liveable. Using 27 ADC bins. |
| 1703 | Dib 3 looks okay, but A1 acts funny sometimes (Fig 1). Debating whether to trigger on it for data. Probably will do. |
| 1731 | More pileups and pulse saturation found with Dib 3. Inconsistency of Dib makes it difficult to trust it for data taking. Some channels are more stable than others (B3 seems most “stable”). |
| Channel | Current ADC bins | Current QET bias [uA] | Modified QET bias [uA] | Modified ADC bins | Comments |
|---|---|---|---|---|---|
| A3 | 25 | -60 | - | 27 | Can't lower QET bias. Don't want to raise ADC bins by much because it brings in more saturated pulses. |
| B3 | 25 | -61 | -63 | 27 | Can't lower QET bias. Slightly better than D3 in terms of noise. |
| C3 | 25 | -65 | - | 27 | Can't lower QET bias. Pretty noisy (on par with D3). |
| D3 | 25 | -90 | - | 27 | Raising the ADC bins slightly helped reduce noise triggers. Can't go below - 90 uA for QET bias. |
| Fig 1: Phonon A1 |
|---|
 |
| 2228 | New DCRC Settings. A1 is still a bit noisy, but I think we can risk it. C3 and D3 are still too noisy to trigger on. Also excluding outer channels D2, B2. C2 excluded for large parasitic resistance. |
|---|
| Table 2: DIB 1, DCRC 33 | |||||||
|---|---|---|---|---|---|---|---|
| Phonon Channel | SQUID Bias (micro A) | Lockpoint (mV) | Modulation Depth (mV) | QET Bias to take data (uA) | QET Bias where Rn/4 (uA) | Inverting or Not? | Trigger [ADC bins] |
| A | 89.8 | 4.70 | 5.4 | -79.7 | -75.6 | I | 18 |
| B | 93.8 | 4.77 | 5.4 | -97.4 | -97.4 | I | 17 |
| C | 91.8 | 5 | 5.3 | -88 | -88 | I | 17 |
| D | 87.9 | 3.2 | 4.9 | -68 | -68 | I | 20 |
| Table 3: DIB 2, DCRC 32 | |||||||
|---|---|---|---|---|---|---|---|
| Phonon Channel | SQUID Bias (micro A) | Lockpoint (mV) | Modulation Depth (mV) | QET Bias to take data (uA) | QET Bias where Rn/4 (uA) | Inverting or Not? | Trigger [ADC bins] |
| A | 56.6 | 4 | 4 | -71 | -66.1 | NI | 21 |
| B | 88 | 4 | 4.5 | -89 | -89 | NI | - |
| C | 90 | 5.3 | 5.5 | 0 | - | I | - |
| D | 88 | 5 | 5 | -76 | -75.9 | NI | - |
| Table 4: DIB 3, DCRC 31 | |||||||
|---|---|---|---|---|---|---|---|
| Phonon Channel | SQUID Bias (micro A) | Lockpoint (mV) | Modulation Depth (mV) | QET Bias to take data (uA) | QET Bias where Rn/4 (uA) | Inverting or Not? | Trigger [ADC bins] |
| A | 80.1 | 4 | 4.9 | -60 | -42(?) | NI | 20 |
| B | 68.4 | 3.2 | 4 | -63 | -63.4 | I | 20 |
| C | 78.1 | 4.2 | 4.5 | -65 | -46.9 | NI | - |
| D | 80.1 | 3 | 4.6 | -90 | -76.8 | I | - |
| 2250 | Tried taking a test data set with the MultiDAQ vi… apparently the autorun flash was on. Waiting for detector to cool. |
|---|---|
| 2307 | Filled LN2 cold trap. |
| Fed Cricket 5 pellets. He deserved it. It's been kind of a long day for him with my music. | |
| 2342 | Did two tests with different trigger combination settings, but exact same trigger thresholds and channels selected. |
| Test 1 : AND(side1)-or-AND(side1) trigger Trigger rate: 11 +/- 2 Hz |
|
| Test 2 : AND (side 1 and side 2) Trigger rate: ~ 1 Hz |
|
| AND(side1)-or-AND(side1) trigger is a more promising trigger combination configuration. | |
| 2352 | Second test with AND(side1)-or-AND(side1) trigger setting. Rate is ~ 6 +/- 2 Hz. Not sure the reason for this. Perhaps due to lack of flashing between tests? |
| 2359 | Did a quick flash between third test with AND(side1)-or-AND(side1) trigger. The rate is higher again (or has the capability to go to 10 and 11 Hz, though it's not consistent there. |