There is nothing spurious about D3 and D4 Hall probes, Ian is too quick to dismiss things. The probes were installed after the drift chambers were in place and I could only reach so far inside the gap. The values read during last run are higher than the values in the middle of the gap because the probes are just at the edge of the yoke. The correlation I obtained recently is to be used with last year's data and any future runs because the permanent Hall probes have not been disturbed. Ramiro On Tuesday, April 16, 2002, at 03:54 PM, Kris Hagel wrote: > Ian, > I am working even as I write to populate afs on rh7.2 stuff. > > The hall probe stuff is for the very near future, but all is not > decided quite yet as I think one would not use it for last years data > given the reasons you indicated. So there are a few decisions to be > made as to how to handle that seamlessly. > > As to who will do it, I anticipate Ramiro will supply me with a recipe > for calculating fields given the hall probe reading and I will > implement it within a short period of time. I hear it will be a week > or two before they can get the measurements for D2 and D5 because of > something going on in the IR or something like that. > > Regards > > Kris > > Ian Bearden wrote: > >> Hi Kris, >> Can you also update BRAT on AFS? I'd like to test your changes:-) >> >> I have a question about using the Hall probe data for the magnetic >> field. >> Is this something that is for the future, or is there a plan to use >> this for >> last year's data? If so, I think we have to be really careful, since >> the >> Hall probe gave spurious readings for D3 and D4 (at least for the few >> runs >> that I checked back in October...). I also guess that at some point >> we have >> to have a better description of magnetic field than the present one. >> If >> this is true, are there any ideas about how to do this and who might >> do it? >> Cheers, >> Ian >> >>> -----Original Message----- >>> From: owner-brahms-dev-l@bnl.gov [mailto:owner-brahms-dev-l@bnl.gov]On >>> Behalf Of Kris Hagel >>> Sent: 16. april 2002 17:34 >>> To: brahms-dev-l@bnl.gov >>> Subject: Changes to BRAT >>> >>> >>> Hello, >>> I have committed some changes to the BRAT repository. They are >>> semi-major (internally; you should notice no functional change), so >>> the >>> revsion number was bumped to 2.3.8 >>> >>> Changes committed. >>> brat/db/run >>> 1. Add and implement BrDbConditionsKeithley. This is a general class >>> for those tables in the RunDB. To get data for specific measurements >>> (ie Hall probe values), it is necessary to know which channel of >>> which >>> unit has the measurement you are interested in and select on that. >>> 2. Modify BrRunsDb and BrRdbmRunsDb to implement access to >>> BrDbConditionsKeithley >>> >>> brat/db/geometry >>> 1. Major surgery on MySQL mode of BrGeometryDbManager to reflect more >>> the style of other db managers. In particular it is now possible in >>> MySQL mode to do geoDb->Update() and the detector volumes will be >>> updated according to which run has been selected. Much of the code >>> for >>> building detector and magnet volumes in MySQL mode has been moved from >>> here to the detector and magnet volume code. No change in >>> functionality >>> and it should be COMPLETELY backward compatible with no changes >>> necessary to existing code. >>> 2. Major surgery on BrDetectorVolume. Change to reflect changes to >>> BrGeometryDbManager in MySQL mode. In particular, the access of the >>> Db >>> is now done from here. Also, add Update() method which gets used from >>> BrGeometryDbManager. >>> 3. Major surgery on BrMagnetVolume. Change to reflect changes to >>> BrGeometryDbManager in MySQL mode. In particular, the access of the >>> Db >>> is now done from here. Add Update() method which gets used from >>> BrGeometryDbManager. >>> 4. Imlement a list of hall probe readings in BrMagnetVolume. This >>> is a >>> TObjArray of BrDbConditionsKeithley objects which were selected based >>> on >>> the start and end time of the selected run. The field will be set to >>> the field corresponding to the first hall probe reading. The routine >>> that does this is currently empty. The field is still set according >>> to >>> the current as before. Once I have the calibration from Ramiro and we >>> decide exactly how this is to be done as well as how to handle >>> analysis >>> of runs before the hall probe reading was implemented, this routine >>> will >>> be filled and will actually set the field to the field that >>> corresponds >>> to the hall probe reading at the given time. REMEMBER, for the time >>> being, the field is still being set according to the current reading. >>> >>> brat/util >>> 1. Beautify the ostream output of BrVector3D and BrRotMatrix. >>> >>> Enjoy these new changes. Enjoyment is defined for the moment as not >>> noticing them. If you notice something behaving different, let me >>> know >>> ASAP. I have tested extensively, but you never know. >>> >>> Regards >>> >>> Kris >>> >>> >> > >
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