BLR Mode
Sets the baselines restorer mode. With a setting of AUTO, the baseline restorer is auto-
matically optimized as a function of trapezoid shaping time and count rate. The set-
tings are SOFT, MEDIUM, and HARD. The baseline restorer is set to fixed rates as
selected.
Live Time Trim
Allows adjustment of the trapezoid pulse evolution time or dead time to optimize LTC
performance. The adjustment range is 0 to 1000; the default value of 250 provides
good LTC performance for a wide range of applications.
Gain Centroid
Sets the centroid (in channels) of the reference peak at the high end of the spectrum for
gain stabilization.
Gain Window
Sets the width (in channels) of the upper and lower sampling windows on either side
of the gain reference peak.
Gain Spacing
Sets the spacing (in channels) between the upper and lower sampling windows. The
windows should be placed so that a shift in the reference peak reflects a significant
change in count rate through the window. For broad peaks, the spacing should be set
so that the window’s edges are not on the flat part of the peak.
Gain Rate Div
The Gain Rate Divisor sets the count rate dividers at the input to the correction register
for Gain. For high count rate reference peaks, increasing the Divider value will smooth
out the correction applied to the system and minimize any peak broadening.
Gain Ratio
The Gain Ratio value is interpreted by the stabilizer as the ratio to maintain between
the two gain windows (ration = upper window/lower window). For instance, a value of
1 would be appropriate for a pure Gaussian peak.
Zero Centroid
Sets the centroid (in channels) of the reference peak at the low end of the spectrum for
zero intercept stabilization.
Zero Window
Sets the width (in channels) of the upper and lower sampling windows on either side
of the zero reference peak.
Chapter 4 - Genie VMS User Interface and Controls
24
Model 9660-9660A ICB Digital Signal Processor
