GBS Elektronik MCA166-USB Dependence of HPGe Detector resolution on shaping time - Manual (Page 2)

2 4 6
sh a p in g tim e (µ s )
0 .6
0 .8
1
1 .2
1 .4
1 .6
F
W
H
M
(
k
e
V
)
L o w e n e rg y F W H M
G M X 2 0 1 9 0 S -1 2 2 k e V
G M X 2 0 1 9 0 S -1 3 6 k e V
G L 0 3 1 0 R -1 2 2 k e V
B G 2 0 2 0 -1 2 2 k e V
B G 2 0 2 0 -1 3 6 k e V
G X 3 5 1 8 -1 2 2 k e V
G X 3 5 1 8 -1 3 6 k e V
E G P C 2 5 -1 8 5 1 2 2 k e V
E G P C 2 5 -1 8 5 1 3 6 k e V
Dependence of FWHM on shaping time at lower photon energies
0 2 4 6
µ s s h a p in g tim e
1 .5
2
2 .5
3
3 .5
4
4 .5
F
W
H
M
(
k
e
V
)
H ig h e n e rg y F W H M
G M X 2 0 1 9 0 S 1 1 7 4 ke V
G M X 2 0 1 9 0 S 1 3 3 3 ke V
B G 2 0 2 0 1 1 7 4 ke V
B G 2 0 2 0 1 3 3 3 ke V
G X 3 5 1 8 -1 1 7 4 ke V
G X 3 5 1 8 -1 3 3 3 ke V
E G P C 2 5 -1 8 5 1 1 7 4 ke V
E G P C 2 5 -1 8 5 1 3 3 3 ke V
Dependence of FWHM from shaping time at higher photon energies
As result can be noticed that the deterioration of FWHM with shorter shaping times is most significant with large
volume detectors. A difference between 1µs and 2µs can be seen at all detectors. Nevertheless, a shaping time of 1µs
may still be useful for high count rate (>30kcps) applications.
The improvement when using 4 or 6 us instead of 2µs is small; for planar detectors the difference is neglible.
So, the special 4/6 µs edition of the MCA166 makes sense in combination with a large volume HPGe and applications,
where the demand for best resolution is high and expected count rates are always low. In all other cases the standard
version 1/2µs is sufficient.