CDC 60 40

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60/40 Ar/CO2 and cosmics, prototype horizontal


1800V, 60/40 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
1900V, 60/40 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
1950V, 60/40 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
Max amplitude ch20, hit threshold 5sigma
1975V, 60/40 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
Max amplitude ch20, hit threshold 5sigma
2000V, 60/40 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
Max amplitude ch20, hit threshold 5sigma


60/40 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 6sigma+
1950V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (64, 79, 110)
1975V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (63, 84, 124)
2000V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (75, 101, 154)
Drift time for 1975V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=0
1975V, hit threshold 5sigma, time thresholds 4 and 1 sigma Estimate of t0 is 88 and tmax is 661, difference is 573, straight-line intercept is 81.7, to match histogram fit t0, use tz_add 6.4
Resolution for 1975V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=6, 60/40 Garfield
File:Run 31842 res20dx tz6 np13 6040.png
1975V, resolution vs hit radius

This does not look nearly as good as 50/50 gas mix. Suspect total flow of 60sccm might be too low for the CO2 MFC. Increase to 80sccm and repeat. Also try Garfield for different gas mixes and look at tmax.