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I think everyone is saying the same thing here, no? With that formula, the current IS the scaling factor. Tim > On Feb 3, 2015, at 8:40 AM, Stepan Stepanyan <[log in to unmask]> wrote: > > 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 ######################################################################## 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