ORTEC DSPEC Pro, Руководство пользователя по оборудованию

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794380D / 0914 2. GETTING STARTED
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digital spectrometers operate well above the peak of the throughput curve. Operating there
allows these instruments to handle an even higher rate of incoming counts, but with less data
into memory and, therefore, a longer count time to the same detection limit. It is possible to
move the peak of the curve to the right (more counts to memory with higher input count rate)
by reducing the pulse rise (and fall) time, thereby trading off resolution for maximum count rate.
Table 2 is a guide to choosing a count
rate that will ensure that the most efficient
operation of your digital spectrometer over
the range of anticipated input count rates
for your application — that is, at or below
the throughput peak — while achieving the
best resolution obtainable from the detector
consistent with that requirement. Enter the
rise time that best matches your dynamic
range of count rate (note that the available
rise-time settings will vary by instrument;
this chart is a general guide only).
The longest rise time shown in the table is
12
µ
s, even though some digital instruments
can be set for rise times as long as 23
µ
s. If throughput is not an issue because all samples are
low rate, increasing the rise time beyond 12
µ
s might achieve a small improvement in resolution.
For planar detectors, such as ORTEC’s GLP, Si(Li), IGLET, and IGLET-X Series, operating at
longer rise times frequently gives improved resolution.
2.5. Troubleshooting
2.5.1. MAESTRO Does Not Connect with the DSPEC Pro
If properly installed and functioning MAESTRO software (or other C
ONNECTIONS
programs)
cannot find and communicate with the DSPEC Pro, check for the following:
!
The DSPEC Pro is not turned on.
!
The USB cable is not properly connected.
!
Check the Master Instrument List on the computer to ensure that the DSPEC Pro is on the
list. If it is not listed, shutdown and restart the DSPEC Pro, then re-run the MCB
Configuration program according to Section 2.2.4.
Input Count Rate
Dynamic Range
Maximum
Throughput
Rise Time
(
µ
s)
0--->20000 9000 12
0--->50000 12500 8
0--->75000 23500 4
0--->100000 37000 2.4
0--->150000 50000 1.6
0--->200k 70000 0.8
0--->220k 85000 0.6
0--->250k 100000 0.4
0--->300k 120000 0.2
Table 2. Rise Time Selection Guide.