In order to reduce the rate of low energy X-rays in the Ge-Detectors of Gammasphere, different absorbers are available. The absorption properties of the different metal foils were measured using a LEPS and a set of standard calibration sources at 25 cm distance. The transmission curves were charcterized by fitting a fermi function
t(E)= A / (1 + exp(-(E-B)/C))
to the measured values . The Parameter A normalizes the values at high energies. B signifies the half-value energy, C the width of the absorption curve. The description with a Fermi-Function seems to work down to values of 20%transmission.
|
|
B
[keV] |
C
[keV] |
Pictures |
| 0.010'' Cu | 41.5(13) | 17.4(12) | Cu |
| 0.002'' Ta
0.010'' Cu |
78.9(6) | 38.7(8) | Ta Cu |
| 0.020'' Cd
0.010'' Cu |
104.3(5) | 25.4(4) |
Cd Cu |
| 0.002'' Ta
0.020'' Cd 0.010'' Cu |
117.3(4) | 21.2(2) | Ta Cd Cu |
