Lynx Genie 2000 Acquisition Window Adjust
Lynx DSA User's Manual - 9240227J
53
DSP Filter Parameters
The DSP Filter settings screen for the Lynx contains the following controls.
Figure 25: Adjust Screen’s DSP Filter Settings
Rise Time
Symmetrically sets the rise time and fall time of the digital filter time response. As
with conventional Gaussian shaping, the degree of noise filtering is proportional to
the rise time selection. The rise time can be selected from 0.2 to 51.0
µ
s in steps of
0.2
µ
s.
Flat Top
Sets the flat top portion of the digital filter time response. The flat top matches the
filter to the detector charge collection characteristics to minimize the effects of
ballistic deficit. The flat top time setting ranges from 0.0 to 3.0
µ
s in steps of 0.1
µ
s.
BLR mode
Sets the baseline restorer mode. With a setting of
Auto
, the baseline restorer is
automatically optimized as a function of trapezoid shaping time and count rate. With
settings of
Soft
,
Medium
and
Hard
, the baseline restorer is set to fixed rates as
selected.
FDisc Shaping
Selects
Normal
or
Low Energy
to optimize the fast discriminator shaping for the
selected detector type;
Normal
: The Fast Discriminator shaping is optimized for Ge
detectors and general gamma spectroscopy; the fast discriminator filter rise time is set
to 100 ns. In
Low Energy
the Fast Discriminator filter rise time is set proportional to
the slow shaping rise time selection.
Pole/Zero
Sets the device’s pole/zero setting from 0 to 4095. The values 1 to 4095 represent
cancellation
ο
f preamplifier time constants from 1.7 ms to 40
µ
s respectively; a value
of zero sets the pole/zero compensation off (time constant of infinity).
