F. T. Rogers

Effect of Pile Irradiation on the Dielectric Constant of Ceramic BaTiO3

A specimen of ceramic BaTiO3, made of reagent‐grade materials at a calcination temperature of 1250°C, was exposed to pile irradiation in the amount of nvt=2.1·1020 at Hanford, Washington. The original ceramic showed a peak in the dielectric constant versus temperature curve usually ascribed to ferroelectricity. After irradiation this peak essentially disappeared, and the dielectric constant was reduced to a nearly constant value over the temperature range 30°C to 140°C. This reduced value is about half of the room‐temperature dielectric constant as determined before irradiation. Evidence is mentioned for a small residual peak in the dielectric constant of the irradiated specimen.

On the Theory of the Electrostatic Beta‐Particle Energy Spectrograph

This paper is a discussion of the effects, on the use of the electrostatic energy spectrograph for charged particles, of the field distortions at the edges of the spectrograph plates and in between the plates. These effects are evaluated and shown not to be negligible in measurements of highest precision. It is shown how, by properly locating the source and detector of charged particles, to eliminate these effects to the extent of a first approximation. The discussion is carried through for only one particular form of spectrograph plates, but the modifications necessary to make it applicable to any other form of spectrograph are adequately pointed out.

A Method for Magnetic Spectrograph Calculations

A method is presented for calculating the kinetic energies of charged particles from magnetic spectrograph data. The method is of some generality in that it is valid for a magnetic field which may depart appreciably from perfect uniformity, provided only that the field focus the particles properly. It is suggested that, although the method is quite lengthy, it might be of use for calculations based on measurements of the highest precision and for calculations of ordinary precision based on data taken with a magnetic field which is not at all uniform.