Fermilab Magnet Test Facility
NMR Measurements of Antiproton Source Magnets


A  few dipoles were measured with an NMR probe either down the length of the magnet, across the aperture, or in the center with varying current.  The program that collected and recorded the data was simple and evolved during the course of the measurements.  The output of each measurement was an ASCII file.  With time the number of columns of data increased.  No columns were deleted and the columns remained in the same order, so if there is a fifth column (for example), it always means the same thing.  The scope of the file header increased with time as well, making it impossible to blindly strip off the first N lines to get to the data.

Most of those measurements were done with an NMR probe only, so they just covered the body field.  Very late in the project we added a Hall probe in order to measure the end field.  Where it is available at all, it was the Hall probe voltage that was recorded.  This must be calibrated by comparing it to the field measured with the NMR probe in a region of uniform field.
 
NMR data column definitions NMR data file index
(partially annotated)		 Back to P-Bar Magnet home

Definitions of the data columns.

Point number

 1, 2, 3, 4, ...

B

 The magnetic field measured in Gauss using the NMR probe.

B-Bmax 

 The magnetic field minus the maximum magnetic field in the file, measured in Gauss.

Position

 The measurement position, in inches.  This may vary or it may not.  The movement axis may be x or z.  While old log books may give some indication of the movement direction, it can usually be inferred from the range of values. 

Current

 The excitation current in the magnet at the time of the reading in Ampere.

BN

 The magnetic field in Gauss, normalized to the requested current (which must be inferred).  This, the simplest normalization possible, assumes a perfectly linear dependence of the field on the current.

BN - BN max

 The normalized field less the maximum normalized field, measured in Gauss.

VHall

 The voltage on a Hall probe in Volts.  I can't remember whether this was an alternate method to get the reported field or whether it supplemented the NMR probe.

Data files

One or more NMR measurements were made on one or more of the following types of dipole magnets.  The measurement data file names are composed in a manner designed to identify the measurement uniquely:  For example, file lda013znz_19850502_071201.txt signifies:

LDA013

 An LDA dipole, number 13 in the series, known to the world as LDA013.

ZNZ

 This is an NMR data file.

19850502

 Date of the measurement. Year 1985, month 05 (May), day 02.

071201

 Time the measurement data was written to disk.  07 hours, 12 minutes, 01 seconds

txt

 These files have ASCII text format. (These files originally had the extension ".dat", but to ease their display here we have renamed them to ".txt".)

LDA

LDG

MDC

SDD

SDE

SDF

SDG
LDA001 LDG001 MDC002 SDD002 SDE001 SDF026 SDG003
LDA002 SDD004 SDE002
LDA003 SDD009
LDA004 SDD016
LDA005 SDD021
LDA013 SDD047
SDD048
SDD049
SDD199 (aka SDD070)



LDA001
lda001znz_19840912_145540.txt z scan, z axis, current unknown
lda001znz_19840912_151650.txt z scan, z axis, current unknown
lda001znz_19840912_152835.txt z scan, z axis, current unknown
lda001znz_19840914_074305.txt z scan at 1182 A, body
lda001znz_19840914_085337.txt z scan at 1182 A, body
lda001znz_19840914_103458.txt Excitation curve near center
lda001znz_19840917_093830.txt z scan at 1172 A, body
lda001znz_19840917_100104.txt z scan at 782 A, body
lda001znz_19840917_105850.txt z scan at 983 A, body
lda001znz_19840917_112511.txt z scan at 1180 A, body
lda001znz_19840917_131732.txt z scan at 1221 A, body
lda001znz_19840917_133507.txt z scan at 1301 A, body
lda001znz_19840917_135016.txt z scan at 1403 A, body
lda001znz_19840918_080608.txt z scan at 1502 A, body
lda001znz_19840925_090401.txt z scan at 1181 A, body
LDA002
lda002znz_19841011_084056.txt z scan at 1182 A, body
LDA003
lda003znz_19841025_161948.txt z scan at 1182 A, body
LDA004
lda004znz_19841026_110603.txt z scan at 1182 A, body
LDA005
lda005znz_19841026_155447.txt z scan at 1182 A, body
LDA013
lda013znz_19850430_100035.txt z scan at 1183 A, through end, 1/2" steps
lda013znz_19850430_104554.txt z scan at 1183 A, body, 1" steps
lda013znz_19850430_110528.txt z scan at 1183 A, through other end, 1/2" steps
lda013znz_19850502_071201.txt z scan at 1183 A, through end, 2" steps
lda013znz_19850502_085340.txt z scan at 1183 A, ends and body, 2" steps
lda013znz_19850506_113929.txt z scan at 1182 A, ends and body, 4" steps
lda013znz_19850507_083437.txt z scan at 1181 A, one end and most of body, 1" steps
lda013znz_19850507_095311.txt z scan at 1182 A, ends and body, 1" steps
lda013znz_19850507_115353.txt z scan at 0 A, ends and body, 2" steps
lda013znz_19850507_131649.txt z scan at 1193 A, ends and body, 2" steps
LDG001
ldg001znz_19850516_070223.txt z scan at 1100 A, ends and body
ldg001znz_19850517_060310.txt z scan at 1100 A, body
MDC002
mdc002znz_19850301_153806.txt z scan at 1182 A, body
SDD002
sdd002znz_19841003_133414.txt z scan at 1182 A
sdd002znz_19841003_143653.txt z scan at 1182 A
sdd002znz_19841003_170205.txt z scan at 980 A
sdd002znz_19841003_175204.txt z scan at 1223 A
sdd002znz_19841003_182626.txt z scan at 1299 A
sdd002znz_19841003_185133.txt z scan at 1403 A
sdd002znz_19841003_190653.txt z scan at 1502 A
sdd002znz_19841019_083019.txt z scan at 1179 A
SDD004
sdd004znz_19841009_124836.txt z scan at 1181 A
SDD009
sdd009znz_19841108_122719.txt x scan at 780 A
sdd009znz_19841108_134837.txt x scan at 980 A
sdd009znz_19841108_140134.txt x scan at 1080 A
sdd009znz_19841108_141136.txt x scan at 1180 A
sdd009znz_19841108_142101.txt x scan at 1220 A
sdd009znz_19841108_143313.txt x scan at 1301 A
sdd009znz_19841108_144315.txt x scan at 1401 A
sdd009znz_19841108_145255.txt x scan at 1500 A
sdd009znz_19841110_083440.txt x scan at 1181 A
sdd009znz_19841110_084014.txt x scan at 1181 A
sdd009znz_19841110_084641.txt x scan at 1181 A
sdd009znz_19841110_084958.txt x scan at 1181 A
sdd009znz_19841110_085254.txt x scan at 1181 A
sdd009znz_19841110_085621.txt x scan at 1181 A
sdd009znz_19841110_085912.txt x scan at 1181 A
sdd009znz_19841110_090211.txt x scan at 1181 A
sdd009znz_19841110_090506.txt x scan at 1181 A
sdd009znz_19841110_090909.txt x scan at 1181 A
sdd009znz_19841110_091138.txt x scan at 1181 A
sdd009znz_19841110_092655.txt x scan at 1181 A
sdd009znz_19841110_092940.txt x scan at 1181 A
sdd009znz_19841110_093159.txt x scan at 1181 A
sdd009znz_19841110_093411.txt x scan at 1181 A
sdd009znz_19841110_093633.txt x scan at 1181 A
sdd009znz_19841110_093859.txt x scan at 1181 A
sdd009znz_19841110_094120.txt x scan at 1181 A
sdd009znz_19841110_094340.txt x scan at 1181 A
SDD016
sdd016znz_19841205_114621.txt
sdd016znz_19841205_121457.txt
sdd016znz_19841205_145542.txt
sdd016znz_19841205_151716.txt
sdd016znz_19841206_113145.txt
sdd016znz_19841206_114649.txt
sdd016znz_19841206_120321.txt
sdd016znz_19841206_131439.txt
sdd016znz_19841206_131508.txt
sdd016znz_19841206_131548.txt
sdd016znz_19841206_134906.txt
sdd016znz_19841206_135906.txt
sdd016znz_19841206_141240.txt
sdd016znz_19841208_082945.txt
sdd016znz_19841208_084503.txt
sdd016znz_19841208_090239.txt
sdd016znz_19841210_090247.txt
sdd016znz_19841210_092754.txt
sdd016znz_19841210_094238.txt
sdd016znz_19860320_072637.txt
sdd016znz_19860320_072641.txt
SDD021
sdd021znz_19841023_130126.txt
sdd021znz_19841023_134219.txt
sdd021znz_19841023_142110.txt
sdd021znz_19841023_145227.txt
sdd021znz_19841023_150938.txt
sdd021znz_19841023_152822.txt
sdd021znz_19841023_155745.txt
sdd021znz_19841023_161204.txt
sdd021znz_19841023_162933.txt
sdd021znz_19841023_170115.txt
sdd021znz_19841023_173811.txt
sdd021znz_19841023_182223.txt
sdd021znz_19841023_191458.txt
sdd021znz_19841023_195820.txt
sdd021znz_19841023_202946.txt
sdd021znz_19841023_210520.txt
sdd021znz_19841023_220432.txt
sdd021znz_19841023_222643.txt
sdd021znz_19841023_230401.txt
SDD047
sdd047znz_19850124_132919.txt
sdd047znz_19850124_134914.txt
SDD048
sdd048znz_19850126_180158.txt
SDD049
sdd049znz_19850126_205220.txt
SDD119
sdd199znz_19841227_142838.txt
sdd199znz_19841227_145735.txt
sdd199znz_19850105_131320.txt
sdd199znz_19850105_131854.txt
sdd199znz_19850105_132129.txt
sdd199znz_19850105_132338.txt
sdd199znz_19850105_132545.txt
sdd199znz_19850105_132830.txt
sdd199znz_19850105_133023.txt
sdd199znz_19850105_133215.txt
sdd199znz_19850105_133400.txt
SDE001
sde001znz_19841220_134615.txt
sde001znz_19850109_081557.txt
sde001znz_19850109_130558.txt
sde001znz_19850109_131646.txt
SDE002
sde002znz_19841212_131258.txt
SDF026
sdf026znz_19841221_104403.txt
sdf026znz_19850102_094515.txt
SDG003
sdg003znz_19850423_142854.txt
Last Updated on 18 August 2000
By David Harding
Email: harding@fnal.gov