MODULATION TRANSFER FUNCTIONS OF THE IONIZATION CHAMBER

The calibration of the 'Fingerhut' ionization chamber

The use of the "thimble" ionization chamber (Fingerhutkammer) has in the past been the only method for comparing the primary X-ray standards of different laboratories, hence the precise calibration of two thimble chambers is discussed in this paper. Five principal factors determine the accuracy of such a calibration, and it is shown that the errors are all, in general, in the same direction. It...

Modulation transfer functions of fractal layers

Transmission characteristics of layers that contain fractal aggregates are investigated. In particular, the modulation transfer functions of these layers are studied in comparison with the case of uniformly dispersed particles. The effects of aggregation type (fractal dimension) and aggregate size are discussed.

Second-order temporal modulation transfer functions.

Detection thresholds were measured for a sinusoidal modulation applied to the modulation depth of a sinusoidally amplitude-modulated (SAM) white noise carrier as a function of the frequency of the modulation applied to the modulation depth (referred to as f'm). The SAM noise acted therefore as a "carrier" stimulus of frequency fm, and sinusoidal modulation of the SAM-noise modulation depth gene...

Spectro - Temporal Modulation Transfer Functions and Speech

Efficiency curve of the ionization chamber of the SIR.

The efficiency of the SIR ionization chamber versus photon energy has been obtained by an iterative method, starting from a few monoenergetic gamma-ray emitters. The relative standard uncertainty on the efficiency curve obtained is lower than 10(-2) above 65 keV. An efficiency curve for beta particles has been deduced in a similar manner, from measurements of (quasi-) pure beta emitters. The po...