Channel counting

In the correlation method the neutron flux density of the specified region is determined from the ratio of pulse measmement channel count rate to detector sensitivity s(E). If we assume that the neutron spectrum in the area of neutron detector location does not depend on the type of SRP being stored in the pit, then for all the measurements s(E) is a constant value. In the next calculations it can be assumed as 1 and thus, the coimt rate being measured can be assumed equal to the value of proportional neutron flux density. 

E. T. Bush, Anal. Chem., 36 1082 (1964). Liquid Scintillation Counting of Doubly-Labeled Samples. Choice of Counting Conditions for Best Precision in Two-Channel Counting. 

A video channel counting detector (CCD) camera transmits the image to the monitor where the indentation is displayed. The control unit reads the diagonals and calculates the microhardness. 

Particle suspensions must be fairly dilute to avoid problems of coincident passage of several particles through the aperture. The volume sampled is set by electronic probes in the mercury column, which start and stop switches as the mercury passes. The instrument used for this work had settings for sample volumes of 50 /xL, 500 /xL, and 2,000 /xL, and was operated with four apertures, 30 /xm, 70 /xm, 140 /xm, and 280 /xm. The Coulter Counter was calibrated with polystyrene latex (PSL) spheres. A computer program was used to convert channel counts and calibration information to particle diameters, surface areas, and volumes after editing spurious data from the paper tapes. Particles were assumed to be solid spheres, since output from the Coulter Counter for sludge is that for spheres of volume equivalent to the randomly shaped particles in the suspension. 

Set minimum and maximum threshold values for particle analysis separately for each channel count particles. 

To find out how the background can be reduced, an analysis has been made of the contributions from different sources of radiations to background. The counting rates were determined twice first with the empty chamber and second, with a blackened vial Inserted into the chamber. By doing this, the photomultipliers cannot detect photons from a vial. The C channel counting rates are shown in Table IV. 

Taking simple single channel counts as an example, if we measure C counts in time Ar and measure a background count B in Ar, then the net count rate (K) is ... 

As it stands, the fit would take equal account of every channel within the composite peak. Clearly, from what we know of counting statistics, channels with fewer counts have a greater uncertainty and should not be allowed an equal say in the fitting process. To take this into account, the equations generated by Equation (9.8) are weighted by the inverse of the variance of the corresponding channel count, Q. Each weighting factor, is ... 

One aspect of computer calculation of MDA is worthy of comment. Let us assume that a peak area is measured by the normal peak integration method (Chapter 5, Section 5.4), the peak background being estimated using a few channels beyond the peak limits on either side of the peak. It is a feature of some programs that if the net peak area fails the critical limit (or similar) test, the upper limit (or MDA) is then estimated from the channel counts within the peak region, using them as an estimate of the... 

Figure 2. XRF spectra showing channel counts for sherd recoveredfrom Tioga...

Based upon experience of "conventional" protection system reliabilities and presupposing, to some extent, that microprocessor based interlocks can be engineered to be at least as reliable as electromechanical interlocks, simple channel counting, allocating a failure probability on demand of to each channel, is used to determine the... 

The high channel count and the rather stringent specifications of this readout system have led us to address a basic issue, namely wh( ther a digital rc adout system) is preferable to an analog system. A digital readout. system has a number of advantages ... 

Ya or consider a channel count different from the maximum. For instance, when many channel maxima fall into regions of small q, where the adiabatic assumptions are likely to fail, one may decide to count channels as open if their potential remains below E until entering a strong coupling region defined by some q < qg. Also, the explicit inclusion of transitions between channels has been discussed as a possible variant of the SACM. ... 

The geometrical arrangement for the measurement is shown in Fig. 17,4. The decay curves will be measured for the points therein indicated, and printed data will be obtained from the TMC analyzer. With each measurement a monitoring channel count will be recorded for normalization of the data. To have good statistics through three decades, we will measure the decay for each point until the maximum capacity of the memory in the analyzer is reached. 

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