ORTEC DSPEC Pro, Руководство пользователя по оборудованию

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794380D / 0914 2. GETTING STARTED
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you should increase values of the rise time for better resolution for expected lower count rates,
or when unusually high count rates are anticipated, reduce the rise time for higher throughput
with somewhat worse resolution.
The Flattop controls adjust the top of the quasi-trapezoid. The Width adjusts the extent of the
flattop (from 0.3 to 2.4
µ
s). The Tilt adjustment varies the “flatness” of this section slightly. The
Tilt can be positive or negative. Choosing a positive value results in a flattop that slopes down-
ward; choosing a negative value gives an upward slope. Alternatively, the optimize feature on
the Amplifier tab can set the tilt value automatically. This automatic value is normally the best
for resolution, but it can be changed on this dialog and in the InSight mode to accommodate
particular throughput/resolution tradeoffs. The optimize feature also automatically adjusts the
pole-zero setting.
The dead time per pulse is approximately
In the Pole Zero section, the Start button performs a pole zero at the specified rise time and
other shaping values. Unlike the optimize feature, it performs a pole zero for only the one rise
time. The pole-zero Stop button aborts the pole zero, and is normally not used.
For the more advanced user, the InSight mode lets you directly view all the parameters and
adjust them interactively while collecting live data. To access the InSight mode, go to the
Insight section on the Amplifier 2 tab and click Start. The InSight mode is discussed in more
detail in the following section. When you are satisfied with the settings, you are ready to acquire
data. Once data acquisition is underway, you may wish to return to MCB Properties... and click
the Insight section’s Start button to adjust the shaping parameters interactively with a “live”
waveform showing the actual pulse shape, or just to verify that all is well.
2.3.2.1. InSight Mode
The InSight display (Fig. 15) shows the actual sampled waveform in the digital processing units
on a reference graticule. The Properties dialog remains active and can be used to change settings
while viewing the pulses.
As none of the traditional analog signals are available in the DSPEC Pro, this mode is the only
way to display the equivalent amplifier output pulse. Note that at the bottom of the window the
marker channel is displayed in units of time.
To exit the InSight mode and return to the PHA display, press <Esc> or go to the Insight section
on the Amplifier 2 tab and click Stop. The PHA mode is set to STOP when you enter the InSight
mode.