ORTEC EASY-MCA-2K, Руководство пользователя

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ORTEC
®
EASY-MCA™ Digital Gamma-Ray Spectrometer User’s Manual 931044C / 1014
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Figure 8. EASY-MCA ADC Tab.
Note that as you enter characters in the data-entry fields, the characters will be underlined until
you move to another field or until 5 seconds have lapsed since the last keyboard input. During
the time the entry is underlined, no other program or computer on the network can modify this
value.
2.3.1. ADC
This tab (Fig. 8) contains the Gate, Conversion Gain, Lower Level Discriminator, and Upper
Level Discriminator controls. In addition, the current real time, live time, and count rate are
monitored at the bottom of the dialog.
The Gate 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 Coincidence mode, a gating
input signal must be present at the proper
time for the conversion of the event; in
Anticoincidence mode, the gating input
signal must not be present for the conver-
sion of the detector signal. The gating sig-
nal must occur prior to and extend 500 ns
beyond peak detect (peak maximum).
The Conversion Gain sets the maximum
channel number in the spectrum. If set to 8192, the energy scale will be divided into 8192 chan-
nels. The conversion gain is entered in powers of 2 (e.g., 8192, 4096, 2048, 1024, 512). The up/
down arrow buttons step through the valid settings for the EASY-MCA.
The Lower Level Discriminator sets the level of the lowest amplitude pulse that will be stored.
This level establishes a lower-level cutoff by channel number for ADC conversions. The mini-
mum setting is 1.
The Upper Level Discriminator sets the level of the highest amplitude pulse that will be stored.
This level establishes an upper-level cutoff by channel number for storage.