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4, 5. MCB PROPERTIES IN MAESTRO
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 resolu-
tion 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 ìs, even though some digital instruments can be
set for rise times as long as 23 ìs. If throughput is not an issue because all samples are low
rate, increasing the rise time beyond 12 ìs 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.
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