Family Of Rays Research Articles

Particle Focusing Properties of the Prolate Spheroidal Magnetic Field and of the Superposed Spheroidal and Uniform Fields

In the first part of the paper values of transmission T and resolution W are computed for prolate spheroidal field magnetic spectrometers with various positions of the source. A value of 15% of 4π has been found for T with W = 1%. The aberration due to size of source has been estimated by computing trajectories from non-axial points. Envelopes and caustics formed by monoenergetic families of rays are mapped for several magnetic rigidities. The second part considers the focusing of particles in superpositions in various ratios of a prolate spheroidal and a uniform field with a common axis. It appears that the position of a point image I of an axial point object O is unrestricted except to the extent that O and I must lie between the foci of the spheroids on the axis and that a narrow zone of angles of emission is used. A β spectrometer using one such ratio is found to give a poorer aperture aberration but an improved source size aberration when compared with the pure spheroidal field instrument. In each case the luminosity is similar to that of the uniform field lens spectrometer.

Refraction of radio waves in arbitrary atmosphere-ray-tracing picture

A development following Hartree, etc., is carried out of ray tracing using REAC differential analyzer. Ray families, on 2k-inch by 32-inch paper, are obtained for an atmosphere with a single n profile (index of refraction versus altitude curve), and for an atmosphere with three n profiles over the region of interest. The n profiles used were measured up to 10,000-foot altitude. The variation in radio field strength with separation between airplanes as measured in a recent air-to-air propagation flight is correlated with a variation or ray density based on index of refraction data taken during the flight. This was a flight which encountered a radio hole followed by its anti-hole (region of erulanced and interfering signals) within the geometrical horizon, and then a second hole and anti-hole at an anomalously large range beyond the horizon. The second anti-hole is accounted for by an anomalous-ranee layer near the ground and one in which the refractive gradient has a negative value nearly equal to l/(radius of earth}. In some respects the correlation is striking between ray-tracing picture and observed radio data.

The zero phase-front in microwave optics

Many microwave optical devices have been designed and studied, at least in part, by the methods of geometrical optics. Common practice in the microwave field has been to focus attention on the family of rays rather than on the surfaces normal to them, the so-called phase-fronts. When phase-fronts are examined, they are usually obtained from the rays by passing along each ray a constant electrical distance from a reference phase-front. The clumsy analytical expression for a phase-front thus obtained renders even a routine investigation of it a burdensome exercise in mathematical manipulation.

Some Contemporary Advances in Physics-VII Waves and Quanta

THE invaluable agent of our best knowledge of the environing world, and yet itself unknown except by inference; the intermediary between matter and the finest of our senses, and yet itself not material; intangible, and yet able to press, to strike blows, and to recoil; impalpable, and yet the vehicle of the energies that flow to the earth from the sun-light in all times has been a recognized and conspicuous feature of the physical world, a perpetual reminder that the material, the tangible, the palpable substances are not the only real ones. Yet its apparent importance, to our forerunners who knew only the rays to which the eye responds and suspected no others, was as nothing beside its real importance, which was realized very gradually during the nineteenth century, as new families of rays were discovered one after the other with new detecting instruments and with new sources. Radiation is not absent from the places where there is no eye-stimulating light; radiation is omnipresent; there is no region of space enclosed or boundless, vacuous or occupied by matter, which is not pervaded by rays; there is no substance which is not perpetually absorbing rays and giving others out, in a continual interchange of energy, which either is an equilibrium of equal and opposite exchanges, or is striving towards such an equilibrium. Radiation is one of the great general entities of the physical world; if we could still use the word “element,” not to mean one of the eighty or ninety kinds of material atoms, but in a deeper sense and somewhat as the ancients used it, we might describe radiation and matter, or possibly radiation and electricity, as coequal elements. Also the problem of the nature and structure of radiation is of no lesser importance than the problem of the structure and nature of matter; and in fact neither can be treated separately; they are so inextricably intertwined that whoever sets out to expound the present condition of one soon finds himself outlining the other. One cannot write a discourse on the nature of radiation alone nor on the structure of the atom alone, one can but vary the relative emphasis laid upon these two subjects, or rather upon these two aspects of a single subject; and in this article I shall restate many things about the atom which were stated in former articles, but the emphasis will be laid upon light.