From: Pawel Staszel (staszel@alf.nbi.dk)
Date: Mon Jan 20 2003 - 10:22:18 EST
Hi All, I've made a look the the T3 data to check whether we can increase signal discrimination threshold. The attached file contains contains figure showing the distribution of the T3 signal width (which corresponds to signal ADC). The curves are plotted for raw hits and for tracks associated hits. It is seen from the figure that current (data comes from run 7491 1.3k events) threshold is set on a quite optimal level, however we can still slightly increase the level (~0.1V) without significant lost on the efficiency. Of course, the action makes sense only if the T3 mapping error still persist. We can also limit the tdc range - now we collect the DC signals from range of ~30000ns but we only need something like 2000ns. The raw hitWidth distributions (from attached file) are plotted without imposing any cut on the tdc. I don't know where the structure in module II comes from, but certainly it does not affect the final efficiency. Regards Pawel. -- ---------------------------------------------------------------------- | Pawel Staszel | | Niels Bohr Institute Tb 8 email: staszel@nbi.dk | | Blegdamsvej 17 phone: (+45) 35 32 53 51 | | København Ø FAX: (+45) 35 32 50 16 | | Danmark | ----------------------------------------------------------------------
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