Hi Claus, Looks very nice. Of course, I would expect the resolution to improve by the means you mention, but this is not bad for a start. I assume the blue curves are the calculated ones from basic principle. Did you have to adjust the refractive index at all? Remember this as one of the possible 'alignment' parameters. Try to have a look at http://delinfo.cern.ch/Delphi/public/afs/conferences/rich95/papers/adam.ps for possible ideas about algorithms. Cheers, Borge +------------------------------------------------------------------------+ | Børge Svane Nielsen E-mail: borge@nbi.dk | | Technical Coordinator http://www.nbi.dk/TECHI | | Niels Bohr Institute Phone: (+45) 3532 5433 | | University of Copenhagen Fax: (+45) 3532 5465 | | Blegdamsvej 17, DK-2100 Copenhagen O, Denmark | +------------------------------------------------------------------------+ On Fri, 7 Sep 2001, Claus O. E. Jorgensen wrote: > > 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/ | > +-------------------------------------------------------------+ > >
This archive was generated by hypermail 2b30 : Fri Sep 07 2001 - 10:04:17 EDT