Calibration parameters for each STED detector: With function f=p0+p1*x+p2*x*x
|
Detector
|
p0 Value |
p0 Error |
p1 Value |
p1 Error |
p2 Value |
p2 Error |
|
STED 1
|
5.67257E-02 |
|
|
|
|
6.80573E-08 |
| STED 2 |
|
|
|
|
|
7.35018E-08 |
| STED 3 |
|
|
|
|
|
5.55624E-08 |
| STED 4 |
|
|
|
|
|
7.71976E-08 |
| STED 5 |
|
|
|
|
|
5.75051E-08 |
| STED 6 |
|
|
|
|
|
5.06241E-08 |
| STED 7 |
|
|
|
|
|
5.79147E-08 |
A quadratic function was fitted to the reference point channel (from experimental histogram) and reference point energy (from simulation histogram). The reference point 'r' was r=mean+(FWHM/2) for a gaussian fitted to each compton edge. A quadratic function was used as it fitted the higher energy AmBe reference point better than a linear function. This is highlighted by the comparisson of "STED 2 Calibration" and "STED 2 Example Linear Fit Calibration" plots below. The p0 error is quite large and p2 error very large (larger than the parameter value in STED1) - however the parameters are highly correlated which may have inflated the error.
CmC histograms were not used as the compton edge could not be located.
For reference the STED 1 correlation matrix:
| |
p0 |
p1 |
p2 |
| p0 |
1 |
-0.92473 |
0.78779 |
| p1 |
-0.92473 |
1 |
-0.91714 |
| p2 |
0.78779 |
-0.91714 |
1 |
|