Difference between revisions of "CDC recent run drift times"
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<h2>Run 2451 - solenoid off</h2> | <h2>Run 2451 - solenoid off</h2> | ||
7 Feb 2015. First run of 2015. Increased sparsification thresholds from 7sigma to 15sigma. <br/> | 7 Feb 2015. First run of 2015. Increased sparsification thresholds from 7sigma to 15sigma. <br/> | ||
− | Garfield 0T 5475-4525 Ar-CO2 has tmax ~560ns | + | Garfield 0T 5475-4525 Ar-CO2 has tmax ~560ns <br/> |
+ | The maxamp shows entries below the sparsification threshold because I used a lower threshold for analysis and the pedestal just before the peak; sometimes there is a smaller peak before a larger one; sometimes the pedestal rises between the start of the data window and the peak. | ||
+ | |||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|+ Hit thresholds 180-100-25, window 44-150 | |+ Hit thresholds 180-100-25, window 44-150 |
Revision as of 13:58, 6 April 2015
Fitted drift time function to straws in run 2451, picked straws with tmax slope < 30, used same straws for subsequent runs.
Used same hit thresholds & window for all runs.
The drift times are for a small group of straws, the amplitude & pedestal histograms are for ALL straws. In the earlier runs the amplitude histograms are cut off at the lower end by the sparsification threshold so I would not pay too much attention to these. I will look to see if there are any straws with a low enough threshold that the amplitude MPV is visible.
Contents
- 1 Run 2451 - solenoid off
- 2 Run 2551 - solenoid off
- 3 Run 2560 - solenoid off
- 4 Run 2577 - solenoid off
- 5 Run 2616 - solenoid at 1200A
- 6 Run 2617 - solenoid at 1200A
- 7 Run 2619 - solenoid at 1200A
- 8 Runs 2616 to 2619 combined - solenoid at 1200A
- 9 Run 2642 - solenoid off
- 10 Run 2644 - solenoid off
- 11 Run 2649 - solenoid off
- 12 Run 2676 - solenoid off
- 13 Run 2688
- 14 Run 2692 - solenoid off
Run 2451 - solenoid off
7 Feb 2015. First run of 2015. Increased sparsification thresholds from 7sigma to 15sigma.
Garfield 0T 5475-4525 Ar-CO2 has tmax ~560ns
The maxamp shows entries below the sparsification threshold because I used a lower threshold for analysis and the pedestal just before the peak; sometimes there is a smaller peak before a larger one; sometimes the pedestal rises between the start of the data window and the peak.
Run 2551 - solenoid off
2-3 March 2015. 3 weeks after disengaging the alcohol bubbler.
Compared with run 2451, drift velocity has increased and gain decreased (but cannot measure the gain decrease very well due to thresholds).
Garfield 0T 5600-4400 Ar-CO2 has tmax ~542ns
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Run 2560 - solenoid off
8 March 2015. 5 days after changing the CO2 gas factor from 0.773 to 0.74 (should result in increase in CO2 %). The gas factor was changed before run 2552.
Comparing with run 2551, drift velocity and gain have both decreased slightly (consistent with more CO2).
Run 2577 - solenoid off
10 March 2015. 1 day after changing the gas mixer MFCs from master/slave "blend" to independent "rate" mode (this change was made before run 2563). For this run the readout window is different from that in all the others.
Run 2616 - solenoid at 1200A
11 March 2015. 2 days after changing the gas mixer MFCs from master/slave "blend" to independent "rate" mode. Garfield 1.75T 5600-4400 Ar-CO2 has tmax ~596ns
Drift times increased substantially due to the magnetic field. Amplitude not inconsistent with that from run 2560 (lower stats in this run).
Run 2617 - solenoid at 1200A
11 March
Run 2619 - solenoid at 1200A
12 March
Runs 2616 to 2619 combined - solenoid at 1200A
11-12 March
Run 2642 - solenoid off
14 March. After moving CO2 controller from ch2 to ch4 (on March 13) and decreasing sparsification thresholds to 8sigma
Run 2644 - solenoid off
16 March.
Run 2649 - solenoid off
17 March. 10 hours after returning CO2 controller from ch4 to ch2
Run 2676 - solenoid off
22 March.
Run 2688
26 March. switched gas mixer back from independent "rate" mode into "blend" mode
Run 2692 - solenoid off
27 March. 1 day after switching gas mixer back from independent "rate" mode into "blend" mode