Neutron Scattering

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oX n .5 1 .0 1 .5
so
0 .0 0 .0 1 .0 i .5
50
6c
an
4a
80
ô
-~ 20
so
20
10
w
10
0
0
0A 0 .5 1,U 1 .5 13 .0 0 .5 1 .U 1 .5
phase eurrent /A phase carrent /A
20
9.5 1 .0 1 .5
15
w
5
0
0.5 1 .0 1 .s 0.5 1 .0 1 .5
phase carrent /A phase torrent /A
Figure 11 .6 : "Phase scans" used to determine thé écho amplitude at thé Jiifich NSE
spectrometer . Symbols indicate count rates normalized to a monitor rate . The oscillating
fines are "fitted" écho signals (assuming Gaussian distribution of wavelengths) . At thé
end of thé scans groups of points corresponding to thé minimal (7r/2-flippers off, 7r-flipper
on) and maximal (all flippers off) obtainable count rates are located .
The horizontal lines
correspond to thé average and thé minimum and maximum intensities . The experimental
value of interest is computed from thé ratio of thé écho amplitude and thé maximum
possible up-down différence . The fines starting at one point at thé beginning of thé scan
are measured magnetic field components (différences to thé starting value) at thé sample
position, they serve to monitor variations of thé magnetic environment .