CDC 55 45

55/45 Ar/CO₂ and cosmics, prototype horizontal

Short runs for range of HV, check pedestal is ok and find MPV

2000V, 55/45 gas, prototype horizontal

Pedestal mean of samples 0-99, ch20, over 1 day

Pedestal std. dev. of samples 0-99, ch20, over 1 day

2025V, 55/45 gas, prototype horizontal

Pedestal mean of samples 0-99, ch20, over 1 day

Pedestal std. dev. of samples 0-99, ch20, over 1 day

2050V, 55/45 gas, prototype horizontal

Pedestal mean of samples 0-99, ch20, over 1 day

Pedestal std. dev. of samples 0-99, ch20, over 1 day

2100V, 55/45 gas, prototype horizontal

Pedestal mean of samples 0-99, ch20, over 1 day

Pedestal std. dev. of samples 0-99, ch20, over 1 day

Fit max amplitude histograms and find optimal HV

55/45 gas, prototype horizontal, 4pedestalsigma (gray) and 5pedestalsigma (blue) hit threshold, fit range 5pedestalsigma+

2000V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (47, 60, 85)

2025V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (49, 65, 98)

2050V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (65, 88, 134)

2100V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (94, 130, 201)

55/45 gas, noise std dev 16.5, hit threshold 5x16.5 = 82.5, fit range 5pedestalsigma+

HV	Fit MPV	Fit sigma (FWHM/4)	Fit 4sigma/MPV	MPV/sigma	4045/MPV	99% point	97% point	95% point
2000	149	42	1.14	3.5	27	60	76	85
2025	181	55	1.21	3.3	22	65	86	98
2050	251	77	1.23	3.2	16	88	117	134
2100	380	119	1.25	3.2	11	130	174	201

Fit drift time histogram

Drift time for 2050V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=0

2050V, hit threshold 5sigma, time thresholds 4 and 1 sigma Estimate of t0 is 104 and tmax is 727, difference is 622, diff between fit maximum and fit t0 is 6.0, straight-line intercept is 95.6, to match histogram fit t0, use tz_add 8.8

Tracking efficiency plot

Tracks/Triggers, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17

tzero=88ns, early hits ignored