ORTEC DSPEC Pro, Руководство пользователя по оборудованию

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794380D / 0914 2. GETTING STARTED
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Figure 16. Mark
Display Selection.
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 256 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 Pro 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 Pro.
If you exit the program with the DSPEC Pro 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. 16. 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.
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
is rejecting the marked pulses.
NegBLDisc This shows when the negative baseline discriminator has been triggered.
Typically this signal only marks the TRP reset pulse. The signal is used
internally in the live-time correction, baseline restoration, and pile-up
rejection circuits.