Appendix A
Structure of Raw Data
A.1 Background Noise
The noise spectral density floor measured for empty pickup coil in the SNS, i.e.
background noise S
bcg
, is fit to a smooth polynomial function S
f
. Since the noise
floor does not vary with temperature, the same function S
f
is then subtracted
from all datasets S DT O
(ω, T ), to obtain the uncalibrated noise spectral density
S uncal (ω, T ) dataset. An example of the raw noise spectral density, and postprocessed (PP) noise spectral density is shown in Fig. A.1.
Fig. A.1 A typical noise
spectrum from DTO (here at
4.00K) is shown for raw
signal (green open diamond)
and with smooth function fit
(dark red line) to background
noise spectrum (open circle,
red) subtracted from the raw
signal (green full diamond)
10
2
10
3
Frequency (Hz)
0
0.2
0.4
0.6
0.8
1
1.2
S ( ) (
0
2
/Hz)
10
-9
noise spectrum empty coil- background
fit function through background
DTO noise spectrum at 4.00K
DTO
© Springer Nature Switzerland AG 2021
R. Dusad, Magnetic Monopole Noise, Springer Theses,
https://doi.org/10.1007/978-3-030-58193-0
65