Exponential Energy Distribution Research Articles

EXPONENTIAL TRAPPING AND CONDUCTION PARAMETERS IN POLYMERS

Abstract Application of nearest‐neighbour band theory to the case of charges trapped on polymer chains shows that the trapping states can have an exponential energy distribution. Comparison with existing photoconduction data suggests that Fermi level in polymers is about 1eV below the conduction band, that the mobility activation energy is 0.1eV or less in commercial polymers and that the conduction bands are narrow.

Energetic electron spectra in the radiation belts

Differential electron spectra in the radiation belts in 10 energy intervals from 0.17 to 4.5 Mev have been obtained from a directional electron spectrometer on satellite 1964-45A. The satellite was launched on August 14, 1964, into a near polar orbit with a 3765-km apogee and a 270-km perigee. Typical quiet-time data of August 15, 1964, are presented. A soft and a hard component both are clearly present in the electron spectra for 1.7 400 km, are fit by exponential energy distributions with characteristic energies of 0.9±0.5 Mev for the hard component and 0.2 to 0.07 Mev for the soft component. The hard component is the remnant of fission electrons injected by the July 9, 1962, high-altitude nuclear test. The soft component becomes softer as L increases, and may largely be due to cosmic-ray albedo neutron decay. For 3.5 < L < 8 the portions of the differential spectra above 0.5 Mev are fit by single exponential distributions with characteristic energies of 0.6 to 0.2 Mev, becoming generally softer as L increases. The quiet-time outer zone electrons peak at lower L for higher energies. The magnetic moments of the electrons at the peaks change along computed inward drift trajectories, which conserve the first two adiabatic invariants. Consequently, this diffusion is a dominant source of these electrons only if a comparable loss process is present. Generally, there are no pronounced changes in quiet-time electron spectra with altitude along a field line in either the outer or inner zones. However, in the outer zone the flux of 0.2-Mev electrons increases by up to a factor of 2 as B changes from 0.24 to 0.1 gauss.

Galactic rotation and vertical intensity of cosmic rays at the magnetic equator

The influence of galactic rotation according to Compton and Getting is discussed for rays in a vertical system of counters at the earth's magnetic equator. For an exponential energy distribution according to Clay: e−V/(3× 1010) the diurnal effect is found to be at least 0.25%.

A possible test of the super-nova hypothesis for cosmic rays

The consequences of Baade and Zwicky's super-nova hypothesis for cosmic rays are pursued under the assumption that the very penetrating part of the cosmic rays assumed to be produced by super-novae are protons. For two recent super-novae in near spirals (Messier 101 and the Andromeda Nebula the energy and range of rays now arriving is calculated (Table 1). Assuming an expansion of the universe according to the general theory of relativity, which started a finite time ago, and an exponential energy distribution of the rays arriving (Clay), approximate expressions are derived for the general ionisation I of cosmic radiation and for the ionisation I′ of the radiation from a special super-nova. It is shown that the latter quantity I′ for the two super-novae produces a variation with sidereal time, which comes within the possibility of future measurements if performed at great water depths, since for the Andromeda Super-nova an effect of the order 0.04% of the observed cosmic ray intensity at sea level is expected. Some indications in existing observations, discussed in a provisional communication (Naturwissenschaften 23, 867, 1935 have turned out to be partly accidental, so that more accurate observations are needed. Observations of this kind by Clay and his collaborators are now in progress in a mine at Kerkrade, and the nature of the variations to be expected at different depths for this location is discussed more in detail (Fig. 2). A possible effect of galactic super-novae in the higher layers of the atmosphere and at high magnetic latitudes is also briefly considered.