[Halld-tagger] Big drift in NMR values?

[Sober, Daniel I]

Tim,
Your 1.7 T file  1_7T_conf1_002.txt contains very different NMR values at the beginning and end:
    NMR @920am 17001 Gauss
    NMR @1245pm 17998
Is 17998 a typo for 16998?
Also, I assume that the 9:20 AM refers to when you re-started the scan at Y=103.65.  Do you have the relevant NMR data for the previous day (Y<103.65)?

I have checked the consistency of the data for the repeated values at Y=103.65.  There is one
crazy value in the new file:  Y=106.35, X=-2.5 (Probe 1), B=13572.02, compared to 16968.16 from Probe 5 in the same file (and16963 and 16967 from the previous day's file.)  Aside from this point,
the differences for the 29 remeasured points have a mean of  +1.54 gauss (probably due to a slight shift in NMR value?) with a std dev of 0.49 gauss.

If there are any other crazy points, my plots will show them easily.

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
________________________________
From: Timothy Whitlatch [whitey at jlab.org]
Sent: Thursday, January 09, 2014 7:09 AM
To: Sober, Daniel I
Cc: Natalie Walford; Alexander Somov; Giles Brown; Eugene Chudakov; Klein, Franz; Hall D beam working group
Subject: Re: Analysis of first tagger field map data

Hi Dan,

Attached are 2 files. The 1.7T includes all data from config 1 at 1.7T the other is all data from 1.5T config 1. We will continue with 0.75T this morning.

The NMR never changed during the 1.5T run probably due to the fact that the magnet was already at operating temp which takes several hours. There is no separate file for the NMR readings. It is stated in the mapping file.

Cheers,

Tim Whitlatch
Hall D Engineer
Jefferson Lab
12050 Jefferson Ave ste 402
Newport News, Va 23606
757-269-5087

________________________________
From: "Daniel Sober" <sober at cua.edu>
To: "Timothy Whitlatch" <whitey at jlab.org>
Cc: "Natalie Walford" <natalie at jlab.org>, "Alexander Somov" <somov at jlab.org>, "Giles Brown" <giles at jlab.org>, "Eugene Chudakov" <gen at jlab.org>, "Franz Klein" <KLEINF at cua.edu>, "Hall D beam working group" <halld-tagger at jlab.org>
Sent: Wednesday, January 8, 2014 3:28:25 PM
Subject: Analysis of first tagger field map data

See http:/faculty.cua.edu/sober/HallD/mapping

Everything looks pretty good so far.
--
Daniel Sober
Professor
Physics Department
The Catholic University of America
Washington, DC 20064
Phone: (202) 319-5856, -5315
E-mail: sober at cua.edu<mailto:sober at cua.edu>