DSPEC 50
®
and DSPEC 502
®
Digital Gamma-Ray Spectrometer User’s Manual
932502G / 0618
Figure 35. Mark
Display Selection.
level. To keep a single pulse displayed, select
Single
. Click
Reset
to refresh the display to see
the next pulse. There will usually be one or two pulses in the “pipeline” that will be displayed
before any change entered will be seen. If the trigger is turned off, the display will be redrawn
periodically, even if no pulse is there.
The
Delay
setting is the time delay between the pulse shown on the display and the trigger
level crossing. The value of the time delay is shown on the display.
Just as for the PHA mode display, the vertical scale can be adjusted with the vertical adjust-
ments. The display can be set to Log mode, but the peak shapes do not have a familiar shape in
this display. The Auto mode will adjust the vertical scale for each pulse. The pulse is shown
before the amplifier gain has been applied, so the relation between channel number and pulse
height is not fixed.
The horizontal scale extends from 16 to 4095 channels. The display is expanded around the
marker position which means that in some cases the peak will disappear from the display when
it is expanded.
The display can be switched from the DSPEC 50 to another detector or the buffer. In this case
the other detector will be shown in the mode selected for it. The buffer will always be shown in
PHA mode. The display will return to the InSight mode when you return to the first DSPEC 50.
If you exit the program with the DSPEC 50 in InSight mode, it will be in InSight mode on the
next startup.
The display can include a
Mark
to indicate one of the other signals
shown in Fig. 35. The Mark is a solid-color region displayed similarly to
that of an ROI in the spectrum. This Mark can be used to set the timing
for the gate pulse. It can also be used to set the shaping times and flattop
parameters to get the best performance. For example, suppose you want to
get the best resolution at the highest throughput possible. By viewing the
pulses and the pileup reject marker, you can increase or decrease the rise
time to obtain a minimum of pileup reject pulses.
4.2.1.1. Mark Types
For the
Mark,
choose either “points” or “filled” (to the zero line) display. This is controlled by
the selection in the
Display/Preferences
menu item. That choice does not affect the PHA mode
choice. The colors are the same as for the PHA mode.
None
No channels are marked in the display.
PileUpReject
The region marked indicates when the PUR circuit has detected pileup and
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