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Hi Norman, OK, fine, so we do not need a scaling factor in conditions DB. What we will need in addition to my list is the parameters of functions B_field(G)=a+b*I(A), and I(A)=c+d*B_field(G), relation between current and central field. Here are parameters: a=-4.298 b=-6.506 c=-0.6657 d=-0.1537 Regards, Stepan On 2/3/15 10:02 AM, Graf, Norman A. wrote: > Hello Stepan, > For any particular analyzing dipole magnet setting, we would either use the > calculated field map at the next highest calculated point and scale it down, or > the next lower calculated point and scale it up. > > "Any scaling factor will depend on values of central fields of closest simulated > field maps and the value of the central field we run with." > Exactly. > > "So, where this independent scaling factor comes into play?" > There is no independent scaling factor. It is derived as you mentioned above. > > Norman > ________________________________________ > From: Stepan Stepanyan <[log in to unmask]> > Sent: Tuesday, February 3, 2015 3:42 AM > To: Graf, Norman A.; McCormick, Jeremy I.; Nathan Baltzell > Cc: hps-software > Subject: Re: Bfield conditions > > Hi Norman, > > Thanks for the explanations, but I m not sure I got it. > Yes, we have field maps at some discrete values of central > fields (or currents) and highly unlikely experiment will run > at any of the existing values. The experimental setting will > be in between some of two existing maps. Any scaling factor > will depend on values of central fields of closest simulated > field maps and the value of the central field we run with. > > So, where this independent scaling factor comes into play? > > Regards, Stepan > > On 2/2/15 11:22 PM, Graf, Norman A. wrote: >> Hello Stepan, >> You provided field maps calculated at discrete values of the central field. >> For simulation and reconstruction we will be using the field maps >> calculated for the nominal running field and apply an overall scaling >> factor to account for deviations in the analyzing dipole magnet current. >> Norman >> ________________________________________ >> From: Stepan Stepanyan <[log in to unmask]> >> Sent: Monday, February 2, 2015 7:15 PM >> To: McCormick, Jeremy I.; Graf, Norman A.; Nathan Baltzell >> Cc: hps-software >> Subject: Re: Bfield conditions >> >> Hello Jeremy, >> >> My list for magnet settings will be the following: >> - beam energy (since magnet setting depends on it) >> - analyzing magnet current as measure on power supply >> - analyzing field as measured in the homogenous region >> - frascati magnet current as measured on the power supply >> - frascati magnet field value as measured in the homogenous region >> Frascati setting is important since the beam direction on the target >> depends on it. >> All of these will be injected to data stream as part of EPICS as well as >> will be >> available through the slow control data base (MYA). >> >> Of course, in addition to the field values in homogenous region we >> should have the full field >> maps stored, available somewhere. We should define how we will scale >> field maps, e.g. >> take the closest available (in current or in central field value) and >> scale, or fit point by point. >> >> By the way, I am not sure what it means scaling factor, may be some one >> can explain me. >> >> Regards, Stepan >> >> >> On 2/2/15 8:55 PM, McCormick, Jeremy I. wrote: >>> Hi, Norman. >>> >>> Thanks for the information. >>> >>> I basically need to know what the database table(s) should look like.... >>> >>> e.g. >>> >>> What columns should it have? What are the units on those columns? >>> >>> The proposal on the JIRA item currently is.... >>> >>> field - the measured By (I think?) in Tesla, presumably of the analyzing dipole >>> >>> scale - scaling factor of the B-field for the run (all components) >>> >>> So is that enough for what we want to do with this information in recon/analysis? Or do we need more columns with additional information? >>> >>> If we need more columns, please tell me what they should be. >>> >>> Also, if there are different conditions measured at different times (multiple magnets?), then we can model them with other classes. >>> >>> Right now, I'd propose a generic "BfieldConditions" object but we aren't limited to having one type if more classes/tables are needed for this. >>> >>> Thanks. >>> >>> --Jeremy >>> >>> -----Original Message----- >>> From: Graf, Norman A. >>> Sent: Monday, February 02, 2015 5:47 PM >>> To: Nathan Baltzell; McCormick, Jeremy I. >>> Cc: hps-software >>> Subject: Re: Bfield conditions >>> >>> Jeremy, et al., >>> We will need to monitor the analyzing dipole current. I assume this is an EPICS variable, or should be. We will also be mounting a Hall probe onto the SVT support plate. This will give us a direct measure of the magnetic field strength. Deviations from nominal settings will give us the scaling factor to use for the simulation/reconstruction. I would use the magnet current as the primary and the Hall probe as check, but we can monitor both during early commissioning. >>> Norman >>> ________________________________________ >>> From: [log in to unmask] <[log in to unmask]> on behalf of Nathan Baltzell <[log in to unmask]> >>> Sent: Monday, February 2, 2015 5:24 PM >>> To: McCormick, Jeremy I. >>> Cc: hps-software >>> Subject: Re: Bfield conditions >>> >>> Hi Jeremy, >>> >>>> current - the beam current in amps >>> I think beam current is not related to chicane settings. >>> >>>> But I'm not sure where this information all comes from... >>> Empirical numbers are magnet currents, from which comes a scale factor relative to some defined nominal value. >>> >>>> current - Will this be in the data stream for the upcoming runs? Or >>>> should we access it through the MYA command line tool? (Obviously >>>> prefer into the data stream.) >>> We will be putting various EPICs variables, including chicane current readbacks, into EVIO every few seconds for the next run. How we will parse it needs to be written and tested. >>> >>> -Nathan >>> >>> >>> >>> On Feb 2, 2015, at 7:44 PM, "McCormick, Jeremy I." <[log in to unmask]> wrote: >>> >>>> -----Original Message----- >>>> From: McCormick, Jeremy I. >>>> Sent: Monday, February 02, 2015 4:43 PM >>>> To: 'Nathan Baltzell' >>>> Cc: Graham, Mathew Thomas; Graf, Norman A. >>>> Subject: RE: Bfield conditions >>>> >>>> Hi, Nathan. >>>> >>>> I'll CC a couple people who might be interested in this... >>>> >>>> It was requested that I add B-field information to the conditions system. >>>> >>>> https://jira.slac.stanford.edu/browse/HPSJAVA-312 >>>> >>>> So I was planning to just add a single table with... >>>> >>>> current - the beam current in amps >>>> >>>> field - measured field value in tesla or kG >>>> >>>> scale - scaling factor of field map for the run >>>> >>>> But I'm not sure where this information all comes from... >>>> >>>> current - Will this be in the data stream for the upcoming runs? Or >>>> should we access it through the MYA command line tool? (Obviously >>>> prefer into the data stream.) >>>> >>>> field - Field value at the IP or some other position? When is this measured? How do we get it automatically? Or do we just input this manually? >>>> >>>> scale - I don't know how we get this number. Is it derived from the current? If it is derived should we even store it separately or just compute on the fly? >>>> >>>> I can add the API regardless of whether we know how to get the information, but we should discuss how to access/load this information up front. >>>> >>>> Thanks. >>>> >>>> --Jeremy >>>> >>>> -----Original Message----- >>>> From: Nathan Baltzell [mailto:[log in to unmask]] >>>> Sent: Monday, February 02, 2015 4:33 PM >>>> To: McCormick, Jeremy I. >>>> Subject: Re: Bfield conditions >>>> >>>> Chicane setting relative to nominal is in data catalog, done manually from the spreadsheet this time. We also have magnet currents in epics. >>>> >>>> This will be something that will be in the jlab mysql run db next time (in progress ...). >>>> >>>> >>>> >>>> On Feb 2, 2015, at 7:23 PM, "McCormick, Jeremy I." <[log in to unmask]> wrote: >>>> >>>>> I might have missed this someplace.... >>>>> >>>>> Do we have any B-field conditions for the runs? >>>>> >>>>> Like current, scaling, etc. >>>> ###################################################################### >>>> ## >>>> Use REPLY-ALL to reply to list >>>> >>>> To unsubscribe from the HPS-SOFTWARE list, click the following link: >>>> https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1 >>> ######################################################################## >>> Use REPLY-ALL to reply to list >>> >>> To unsubscribe from the HPS-SOFTWARE list, click the following link: >>> https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1 >>> >>> ######################################################################## >>> Use REPLY-ALL to reply to list >>> >>> To unsubscribe from the HPS-SOFTWARE list, click the following link: >>> https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1 > > ######################################################################## > Use REPLY-ALL to reply to list > > To unsubscribe from the HPS-SOFTWARE list, click the following link: > https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1 ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the HPS-SOFTWARE list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1