Dear Collaborators, Thanks to Pawels new Bfs tracking and Djamels calculation of reflections on the Rich mirror I've been able to do the first rough pid with the Rich. You can find plots on the web: http://www.nbi.dk/~ekman/rich/RICH.html I can think of (at least) 4 things that can improve the RICH pid: 1) Align the geometry of the detector. For now I just use an old geo file. I don't know how to tune the geometry. The calculated ring centers (reflection of the track lines) seems to hit in the center of the rings, but since I find the rings from the center it's difficult to check the correlation. 2) Implement the correct geometry of the image plane. The tube positions is given by BrChkvParameters, and they are only approximate - there are some offsets missing - who knows the exact geometry? 3) Make gain calibrations. Maybe we can find a single photon peak in the raw data (or in events with only one track), and calibrate to that. I'll look at that. 4) Improve the ring-finding method. For know I just make a histogram of signals per dR (R=distance from center) and normalize to the area of the dR rings - this histogram is then fitted with a gaussian, and in most cases a nice peak is found. The ring radius is then set to mean of the peak. Maybe we can use some more sophisticated recognition routines (any ideas?) Any comments or suggestions are welcome! Have a nice weekend, Claus +-------------------------------------------------------------+ | Claus Jørgensen | | Cand. Scient. Phone : (+45) 33 32 49 49 | | Cell : (+45) 27 28 49 49 | | Niels Bohr Institute, Ta-2, Office : (+45) 35 32 53 07 | | Blegdamsvej 17, DK-2100, E-mail : ekman@nbi.dk | | University of Copenhagen Home : www.nbi.dk/~ekman/ | +-------------------------------------------------------------+
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