Recent development in measuring methods for electrons, are reviewed according to three categories: track detectors, particle counters and current detectors. Methods for energy measure-ment are also reviewed for both non-magnetic and magnetic types of analyzing. Description is made of those phenomena such as backscattering, secondary electron emission, surface effect, plasma effect, radiation induced current and radiation damage, which are considered to affect the above., measurements with magnitude of the same order or more compared with the signal.
The shock response of nonlinear spring which has weak damping is available to find the static characteristic of the spring, and numerical solutions from step excitation are given in this paper. But this dynamic solutions are not applicable to the porous cushioning material such as poly-urethane foam, for the effect of the air flow resistance in the porous media. Then the influence of the fundamental wave and its harmonic wave of velocity component on damping and dynamic stress-strain curve are studied by the theories of steady and unsteady laminar boundary layer flow. The theoretical values are nearly coincident with the values experimentally obtained.
The density of a liquid can be determined by the pressure difference at two points of known height difference in the liquid. This paper is concerned with two hydrometric methods by this principle. The pressure difference is measured by an apparatus with two equal bellows, which are connected by rods, keeping the bellows at a constant distance. The first method is to measure the pressure difference of two points directly. The second method is to measure the pressure difference of two points by liquid purge. These hydrometric methods make it possible to measure continually the density of liquid and is applicable to industrial practice.
The liquid scatterer has been tested in place of a solid state scatterer (dielectrics) and a lead absorber, which are components in the ordinary Compton dose meter, using the source of Co-60 and a 18 MeV electron Linac. The induced current was observed in the external circuit in the same way as the ordinary scatterer because the Compton electrons are generated in the liquid by gamma- or X-ray irradiation. It was obtained that the output of this detector was proportional to dose absorbed by the scatterer and was almost the same value regardless of the kinds of liquid, and the dose could be measured continuously and controlled in any values by regulating the flow-ing speed of liquid. In the practical applications, this is a very convenient and useful instrument for the reason that the dose absorbed in irradiated liquid sample itself can be measured directly.
A digital densitometer for presenting the peak densities of spectral lines on photographic plates, which works in conjunction with a photoelectric digital comparator previously developed, is con-structed to complete a fully automatic digital densitometer comparator. The measurement of the optical densities is carried out in parallel with the comparator operation by means of a logarithmic analog-to-digital converter including a ratio circuit. In the converter, the exponential shaped voltage of which peak height is proportional to the reference light intensity is compared with the sampled voltage corresponding to the light flux passing through the center of spectral line image. The pulses generated in the exponential function generator and the voltage comparator are re-spectively used as the start and stop commands for a conventional linear analog-to-digital converter. The overall accuracy of the densitometer is better than one percent in a density range up to 2 (O.D.). The instrument can also provide two modes of operation, one of which is a manual mode for taking the density at any point of the plate and the other is a semi-automatic mode for presenting the density profile of the spectral line both in digital forms.
The process of producing the hologram of an incoherently illuminated object and that of obtaining the reconstructed image from the hologram are described mathematically based on the Fresnel-Kirchhoff diffraction integral. Formulas are given which represent the magnification, posi-tion and separation of the reconstructed images. Distortion term does not appear in the case of incoherent holography. The condition for obtaining Fourier transform holograms is outlined. A system consisting of two spherical mirrors and a beam splitter is proposed.
An accuracy of live time in multi-channel pulse height analyser is given theoretically and experi-mentally. It is theoretically deduced that the sampl-ing method used generally is accurate for the measurement of live time. Experimental values of the error of live time increase progressively with counting rate, and at higher counting rate than about 2, 000 count/sec. they exceed theoretical ones. This may be caused by the pulse shape of multi-channel pulse height analyser used in this experi-ment.
By introducing methanol vapor into the 6328 Å He-Ne laser cavity, the laser power output has increased. It can be easily controlled by changing the vapor pressure of methanol. Thé output char-acteristics have been analyzed on the basis of current dependence of small signal gain and the saturated gain of the laser medium. The increments of popula-tion density of Ne 3s2 can be deduced 18% and 64% at the temperatures of methanol reservoir of 25°C and 60°C, respectively.