CDC recent run drift times

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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.


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

Hit thresholds 180-100-25, window 44-150
Drift time fit straws with param 6 < 30
zoomed in
max amplitude - pedestal
pedestal


Run 2551 - solenoid off

2-3 March 2015. 3 weeks after disengaging the alcohol bubbler. Garfield 0T 5600-4400 Ar-CO2 has tmax ~542ns

Hit thresholds 180-100-25, window 44-150
Drift time fit straws with param 6 < 30
zoomed in
max amplitude - pedestal
pedestal

Run 2560 - solenoid off

8 March 2015. 5 days after changing the CO2 gas factor from 0.773 to 0.74. The gas factor was changed before run 2552.

Hit thresholds 180-100-25, window 44-150
Drift time fit straws with param 6 < 30
zoomed in
max amplitude - pedestal
pedestal

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.

Hit thresholds 180-100-25, window 64-170
Drift time fit straws with param 6 < 30
zoomed in
max amplitude - pedestal
pedestal

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

Hit thresholds 180-100-25, window 44-150
Drift time fit straws with param 6 < 30
zoomed in
max amplitude - pedestal
pedestal

Run 2617 - solenoid at 1200A

11 March

Hit thresholds 180-100-25, window 44-150
Drift time fit
zoomed in
max amplitude - pedestal
pedestal

Run 2619 - solenoid at 1200A

12 March

Hit thresholds 180-100-25, window 44-150
Drift time fit
zoomed in
max amplitude - pedestal
pedestal

Run 2642 - solenoid off

14 March. After moving CO2 controller from ch2 to ch4 (on March 13) and decreasing sparsification thresholds to 8sigma

Hit thresholds 180-100-25, window 44-150
Drift time fit
zoomed in
max amplitude - pedestal
pedestal

Run 2644 - solenoid off

16 March.

Hit thresholds 180-100-25, window 44-150
Drift time fit
zoomed in
max amplitude - pedestal
pedestal

Run 2649 - solenoid off

17 March. 10 hours after returning CO2 controller from ch4 to ch2

Hit thresholds 180-100-25, window 44-150
Drift time fit
zoomed in
max amplitude - pedestal
pedestal


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

Hit thresholds 180-100-25, window 44-150
Drift time fit
zoomed in
max amplitude - pedestal
pedestal