LE Offsets GRINCH
Working on the Leading Edge offsets for the GRINCH. Starting with LED data from GEn when we plugged in the other LED inside the GRINCH which was able to illuminate the whole detector.
1) Start with aligning the LED signals. This should account for things such as cable length and any differences between the four vetroc modules. GEn Run 3036 (done)
2) Put those fits into the database and replay the data again. (Sort-of done. This is in a local copy in the grinch environment at on the a-onl machines. Type "gogrinch" to get there).
3) Fit the LE for clusters. Run 3038. Not making a theta or phi cut to try and illuminate as much of the detector as possible. Made a macro to read back in those fits and adjust the LE. Since a large portion of the detector is out of where there are a good tracks, I fit the LE by hand where I could, and then guessed the rest of them by following the trends of the neighboring PMTs. (Done, although I may want to replay a few more runs to try and get some more statistics and do the fitting again).
4) Put those new offsets into the database and replay the data. (Not done yet).
5) Apply to GMn data? I would need to write a macro that reads in the offsets that the pass1 data was replayed with, undoes them, then applies these new offsets. Or I could do a few replays of my own with my own database to test it. That's assuming it's a valid procedure to attempt to apply these offsets to the GMn data where we had some different HV values. I do think at the very least it's a good place to start, because factors such as cable length and geometry of the grinch and internal processing times of the vetrocs should all be the same. (We don't have LED data that fills the whole detector from GMn.
Updated by Maria Satnik 3 months ago
Looking to see how these offsets affect the mean and the variance of the clusters. It appears we did a good job of centering them at 200ns, but the variance didn't seem to change much. I was hoping it would shrink right down. Need to look up how to plot histos from different programs on top of each other to see how it really changed.
Updated by Maria Satnik 2 months ago
I made a macro to plot the histograms on the same canvas. Blue is without the offsets from the LED data (run 3036), red is with the offsets from the LED data (run 3038) and black is with the additional offsets I talked about above (applied to 3038). The integrals of the histograms are normalized to 1 in this plot to account for different number of clusters found between the three sets of data. We can see that the offsets from the LEDs really make a big difference in the variance. This is partially due to needing to use a slightly larger time cut. The second round of offsets that I describe above (comparing red and black) don't make a huge difference in the variance, although we do see a difference in the mean time. I think this shows that using the LED offsets took care of a lot of the systematics. I think I will go head and start working on applying the LED offsets to some GMn data and see what that looks like.