ORTEC DSPEC Pro, Руководство пользователя по оборудованию

Страница: 43 / 108

794380D / 0914 2. GETTING STARTED
33
4) Position the marker in the
137
Cs peak, then switch to the Stabilizer tab. In the Gain Stabilizer
section, click Suggest to capture the peak channel and width of the
137
Cs ROI, click the cor-
responding Initialize button, then return to the Amplifier PRO tab and mark the Resolution
Enhancer checkbox.
5) Acquire the first “training” spectrum, then record the FWHM for the
241
Am,
109
Cd,
137
Cs, and
60
Co peaks. Clear the data, acquire another spectrum, and record the FWHMs for the target
peaks. After 2–4 iterations, the FWHMs should no longer change appreciably, indicating the
Resolution Enhancer is “trained.” Save the final spectrum with a name (and optional sample
description) indicating the Resolution Enhancer was used to improve peak resolution.
6) The table of adjustments will be stored in the DSPEC Pro’s memory, and will continue to be
used each time you mark the Resolution Enhancer checkbox, until “retrained.”
NOTE
If you change any parameters that affect peak shape, you must repeat this “training”
procedure.
To Turn the Enhancer Off
1) With the Resolution Enhancer checkbox still marked, switch to the Stabilizer tab and click
the Gain Stabilizer section’s Initialize button.
2) Return to the Amplifier PRO tab and unmark the Resolution Enhancer box.
3) Re-optimize.
2.3.4. ADC
This tab (Fig. 18) contains the Gate, ZDT Mode, Conversion Gain, Lower Level Discrimi-
nator, and Upper Level Discriminator controls. In addition, the current real time, live time, and
count rate are monitored at the bottom of the dialog.
Gate — This control allows you to select a positive TTL logic level gating function. With gating
Off, no gating is performed (that is, all detector signals are processed); with gating in Coinci-
dence mode, a gating input signal must be present at the proper time for the conversion of
the event; in Anticoincidence, the gating input signal must not be present for the conversion
of the detector signal. The gating signal must occur prior to and extend 500 ns beyond peak
detect (peak maximum).