I can reply to that one although I'm not the author of the calibration. It turned out that one could not calibrate all runs together for the time offsets. I've made such a calibration and only 5 slats or so were missing due to bad pedestals (much too wide) or very low stat for the very outer slats. But Flemming checked it by doing a slewing correction and noticed that this time offset cal. was not good enough for particular runs (it was only an average over all 1000B runs). So, splitting the cal. job to smaller groups of runs would decrease the statistics and rule out the outer slats (because high field). This was as far as I know Flemming's strategy. Now, we can discuss if we do need these slats. As you already said, the point is to identify the particles. If one can do that despite a small "offset" of the time offsets, so why not ? Djam On Wed, 10 Jul 2002, Ian Bearden wrote: > The outer slats are missing in some of the 1000B runs because of the > particular time of flight calibration. I'll let the person who did the > calibration explain why it is only valid for a fraction of the run. > > Also, rather than complaining that the dsts are bad, why not learn how to > produce them, and redo them? > > Ian > > > -----Original Message----- > > From: owner-brahms-dev-l@bnl.gov [mailto:owner-brahms-dev-l@bnl.gov]On > > Behalf Of Jens Ivar Jordre > > Sent: 9. juli 2002 20:11 > > To: brahms-dev-l@bnl.gov > > Subject: Re: problem run/dst > > > > > > Here is a followup on Flemmings notification on some selected > > runs. Peter and I > > have been working today with the latest MRS DSTs > > /brahms/data05/data/dst/MRS. > > The following lists the different settings and corresponding > > files that we found > > to be bad in one way or another or simply differing from the > > other files in that > > directory (such as having trigger 6 or not): > > > > 90 degrees 350A : > > 5693, 5694, 5696 has a bad mass2 vs p performance (bending down) > > 5696 also has very few good tracks > > > > 90 degrees 350B : > > After 5729 the spectrometer was moved back!!!!!! > > > > 90 degrees 1000B 1 - outer TOFW slats missing : > > Before 5895 spectrometer was moved back!!!!!! > > 5901 and 5902 have bad matching cuts > > For run 5931 and run 5932 there are no TPM2 tracks!!!! > > > > 90 degrees 1000B 2 - outer TOFW slats ok : > > 5940 has bad matching cuts > > 5962, 5963, 5965, 5971, 5972, 5973, 5974 have bad matching cuts > > 5983 seems to have reversed polarity when plotting theta vs p > > > > 45 degrees 700B : > > 53XX don't have trigger 6 while 55XX have it > > > > 40 degrees 1000B : > > 5572 is according to the run log a zero field run, i.e. > > only D1 @ 1/3 B > > > > 35 degrees 700B : > > 5388, 5394, 5398, 5399 have no trigger 6 > > 5436 had an IoServer crash and thus no data > > > > Flemming Videbaek wrote: > > > I have found a couple of small issues in the 90 deg data sets > > > > > > > > > > > > a) the B350 run 5734 has the D5 pushed back by 50 cm and the mdst5734 > > > ought to go to a different directory in order not to > > > > > > be merged with the 5712-5721 runs. > > > > > > > > > > > > b) The low gain BB tubes runs 5693,94 and 96 seem all have a different > > > t0, so they are not useful even after the > > > > > > vertex calibrations that was done. (easily seen in the PID plots. > > > > > > > > > > > > ------------------------------------------------------ > > > Flemming Videbaek > > > Physics Department > > > Brookhaven National Laboratory > > > > > > > > > > > > tlf: 631-344-4106 > > > fax 631-344-1334 > > > e-mail: videbaek@bnl.gov <mailto:videbaek@bnl.gov> > > > > > > > > > -- > > Jens Ivar Jřrdre > > e-mail: JensIvar.Jordre@fi.uib.no > > reg.mail: Dep. of Phys., Allégt. 55, N-5007 BERGEN, NORWAY > > phone: +47 55582792 > > > > > > > > > > > > > -- Djamel Ouerdane ------------------------------------------o | Niels Bohr Institute | Home: | | Blegdamsvej 17, DK-2100 Ř | Jagtvej 141 2D, | | Fax: +45 35 32 50 16 | DK-2200 Copenhagen N | | Tel: +45 35 32 52 69 | +45 35 86 19 74 | | http://www.nbi.dk/~ouerdane | | ouerdane@nbi.dk | o---------------------------------------------------------o
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