 |
 |
Without pulse fitting, or the mode7 emulation, all of the hit times would be at times that are multiples of 4 ns, corresponding to the time of the first sample crossing the threshold. However, we use a pulse fitting algorithm, which improves our resolution on timing for the hit, as well as time-walk corrections. If a fit fails the pulse fitting and the mode-7 emulation, then we use the time of the first sample that crosses the threshold. In the "bad files" we see a lot of low energy hits with multiples of 4ns times, which probably failed both these two methods of time reconstruction. There is also another thing in here I forgot to mention: there is also a shift in the timing window of when multiple hits are, between the "bad" files and the "good" files. What i mean is, you'll see a peak in hit time, corresponding to the trigger window. This peak is shifted between files generated using the old version of the DST and the new version. On Tue, Sep 20, 2016 at 10:47 AM, Maurik Holtrop <[log in to unmask]> wrote: > Hello Sebouh, > > There was a bug in the DST maker where it would only write ECAL hits that > were part of a cluster, and if a hit appeared in two clusters, it would > write that hit twice. This is not the correct behavior. I fixed this in > Issue44 (https://github.com/JeffersonLab/hps-dst/issues/44) and then > merged to master. > > So, #1, is because now the unrelated and out of time hits are also in the > DST. > I don’t think this explains #2. > #3 Since the FADC samples at 250Mhz, I would expect all ECAL hit times to > be at multiples of 4ns, but perhaps I am missing something? > > Best, > Maurik > > On Sep 20, 2016, at 9:37 AM, Sebouh Paul <[log in to unmask]> wrote: > > Has anyone made modifications to the DST maker since pass0 began in June > 6? Nathan ran recon and DST maker on some files at the beginning of > August, and there are some problems with the DST files produced: > > 1) 1.5x more ecal hits per event than in DST files generated in pass0. > 2) two cluster time difference has a much larger sigma than usual. > 3) many ecal hits have hit times that are exact multiples of 4 ns. > > I ran DQM on the corresponding LCIO files, and saw none of these effects, > so the problem must be in the DST maker. > > thanks. > > ------------------------------ > > Use REPLY-ALL to reply to list > > To unsubscribe from the HPS-SOFTWARE list, click the following link: > https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1 > > > > ------------------------------ > > Use REPLY-ALL to reply to list > > To unsubscribe from the HPS-SOFTWARE list, click the following link: > https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1 > ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the HPS-SOFTWARE list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1