Pulse-height selection

Pulse-height selection.6 In some detectors, the mean height of the... 

Considerable confusion results because the terms pulse-height analysis, pulse-height discrimination, and pulse-height selection are sometimes used loosely or interchangeably. We shall follow The International Dictionary of Physics and Electronics, D. Van Nostrand Company, Inc., Princeton, N. J., 1950, pages 715 and 710, where the instruments for these techniques are described as follows ... 

Fig. 2-4. Mean pulse height versus quantum energy, to illustrate pulse-height selection of characteristic lines. Side window tube, 3-in. diameter 0.005-in. wire operating at 1275 v filled with argon plus 10% ethylene total pressure, 15 cm of mercury (proportional counter) gain, 3.5 X 104. (After Friedman, Birks, and Brooks, A STM Spec. Tech. Publ., No. 157, page 3. Copyright 1954. American Society for Testing Materials.)...

In the analysis of light elements where the wavelength differences to be resolved are large and it is difficult to get good crystals, pulse-height, selection has a promising future. 

There are ways of coping with these interferences. Pulse-height selection (2.13) is a direct method. As we shall see in Chapter 7, a particularly bad case, the determination of tungsten in aqueous solution with scattered target line and the identical line from the sample superimposed, could be handled successfully by properly correcting the background. 

Fig. 8-2. Background in the determination of aluminum in Alnico. Pulse-height selection facilitates the determination by reducing in importance the background and the lines (in 5th- and 3rd-order reflection) of the matrix elements, nickel and titanium. (After Noreleo Reptr., 3, 78.)...

Table 8-2 contains unpublished results fron the authors laboratory that illustrate the effectiveness of pulse-height selection in the determination of light elements. In the case of silicon, the background was due mainly to scattered x-rays. In the case of sulfur, multiplier phototube noise was also present. The counting interval was 10 seconds for Nt (total count) and for Nb (background). The excellent results for sulfur could not have been obtained had there not been careful and fortunate selection of the multiplier phototube. 

Table 8-2. Effectiveness of Pulse-Height Selection (PHS) in Reducing Background...

Analyzing crystals, resolution by, compared to pulse-height selection, 47, 61, 63... 

Discrimination by adjustable path length in gas-flow Geiger Counters, 258 Discriminators, see Pulse-height discriminator Pulse-height selection Distribution of sample in spot test, 228 Divergence of x-ray beam in slit system, 111, 112... 

Nitrocellulose foils as standards of thickness, 297-300 Nobel Prize awards, 2 Noise, from amplifier, 59, 60 from multiplier phototube, pulse-height selection for removal, 219 Nomenclature of x-ray analytical instruments, 124, 125... 

Pulse-height selection, for removal of scattered x-rays, 219 in elimination of higher-order background contributions, 63, 64, 218 in light-element analysis, 62, 217-219... 

Pulse height selection using a proportional counter (x-rays). 

Sealed proportional counter tube and DC voltage at plateau Pulse height selection El 5 volts Ey-out... 

Pulse height selection Ej 5 volts Eu - out Rate meter T.C.4 2000 C/S full scale Chart speed - 1 inch per 5 minutes... 

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