[Halld-tagger] Excitation dependence compared with Tosca

[Timothy Whitlatch]

I can supply the current. I will send it later.

Sent from my iPhone

> On Jan 17, 2014, at 12:23 PM, Daniel Sober <sober at cua.edu> wrote:
> 
> The attached table and figure (and the Excel spreadsheet it comes from) shows a comparison between the field/current ratio (at pole center) from the data and from Tosca.  Since your spreadsheet gives the current only in "PPM", I have adjusted the ratios to make them agree at 1.5 T.  The consistency at 0.75 T, 1.5 T and 1.7 T looks quite good.  (I have connected the measured points by straight line segments to make it easier to see where they are.)  
>                     Measured ratio (P1)        Tosca ratio
>     0.75 T    2.0867                                 2.085 (average of 0.6 and 0.9 T)
>     1.50 T     2.0307                                2.0311
>     1.70 T    1.8461                                 1.8582
> This is important in case we have to interpolate between the maps to run at an excitation other than 1.5 T.
> 
> The measurements at 0.1 T and 0.0536 T are way off the curve.  Since the Hall probes and the NMR agree, the only sensible explanation is an offset in the power supply reading.  Does anyone have a calibration of the current reading?  As long as we have the NMR probe, I guess the current is not important.
> 
> Dan
>> -- 
>> Daniel Sober
>> Professor
>> Physics Department
>> The Catholic University of America
>> Washington, DC 20064
>> Phone: (202) 319-5856, -5315
>> E-mail: sober at cua.edu
>> 
> 
> -- 
> Daniel Sober
> Professor
> Physics Department
> The Catholic University of America
> Washington, DC 20064
> Phone: (202) 319-5856, -5315
> E-mail: sober at cua.edu
> <B_current_ratio_vs_Tosca.pdf>
> <Hall_Probe_calib_config2.xls>
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