Programmable Controls
Lynx DSA User's Manual - 9240227J
139
FAST DISC 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; LOW ENERGY:
The Fast Discriminator filter rise time is set proportional to the slow shaping rise
time selection.
FAST DISC MODE
Sets the Fast Discriminator Threshold mode. AUTO: the threshold is optimized
automatically above the system noise level; MANUAL: allows threshold to be
adjusted manually.
FAST DISC SETTING
Active when manual FAST DISC MODE is selected; sets the Fast Discriminator
threshold level, range is 0 to 100%; the front panel ICR LED serves as a user aid
when manually setting the Fast Discriminator threshold.
SLOW DISC MODE
Sets the Slow Discriminator Threshold mode. AUTO: the threshold is optimized
automatically above the system noise level; MANUAL: allows threshold to be
adjusted manually. Manual mode is useful when working with low energy
application. Please refer to the
Low-Energy Applications
on page 109 for more
details.
SLOW DISC SETTING
Active when SLOW DISC MODE is set to MANUAL; sets the Slow
Discriminator threshold level, range is 0 to 100%. This feature is useful to expose
processing of very low energy events by setting LLD MODE to MANUAL,
Please refer to the
Low-Energy Applications
on page 109 for more details.
PUR/LTC MODE
ON/OFF; ON: Enables pileup rejector and live time corrector (LTC). LTC
generates dead time to extend the acquisition time to compensate for events that
are piled up and rejected; OFF: pileup rejector and LTC disabled. Refer to
PUR/LTC Operation
on page 189 for more information
LT TRIM
Allows adjustment of the trapezoidal pulse evolution time or dead time to
optimize Live Time Correction (LTC) performance. The adjustment range is 0 to
1000; the default value of 500 provides good LTC performance for a wide range
of applications. Refer to
PUR/LTC Operation
on page 189 for more information.
OVERLOAD RECOVERY EXTENSION TIME
Time in microseconds added to the default overload recovery when a cosmic
event overloads the preamplifier. The default recovery time in the Lynx is
approximately 2.5x the shaping time (2x Rise + Flat Top). The value specified
through the Overload Recovery Extension Time ranges from 0 microseconds to
6,550 microseconds in steps of 10 microseconds.
