CDC prototype more on timing 3
From GlueXWiki
Revision as of 15:11, 20 March 2012 by Nsjarvis (Talk | contribs) (Created page with "Latest approach to hit finding is as follows # Find a hit channel ## Calculate mean pedestal P_{m} & s.d. (sigma) for first 100 samples in 100 events (trigger is approx sample 2...")
Latest approach to hit finding is as follows
- Find a hit channel
- Calculate mean pedestal P_{m} & s.d. (sigma) for first 100 samples in 100 events (trigger is approx sample 200)
- Set a threshold T_{p} (eg 3.5 sigma) for further investigation, eg P_{m} + T_{p} , select events & channels where adc value exceeds this
- Calculate event pedestal P_{e} as mean of samples 90 to 190 in current event
- Select events where adc value goes over high threshold T_{h1} + P_{e} (T_{h1} ~ 5sigma)
- Find time
- Upsample data from samples 150 to 350 (max drift time + trigger time is approx sample 290)
- Search forward to find point x1 where data goes above a not quite so high threshold T_{h2} + P_{e} where T_{h2} ~ 4sigma
- Find a local pedestal a number of upsampled points (eg 15) before x1
- Search backward from x1 to find point x2 where data goes below second not quite so high threshold T_{h2} + P_{e} where T_{h2} ~ 4sigma
- Find a local pedestal a number of upsampled points (eg 15) before x1