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The latitude effect of cosmic radiation
NOTES FROM THE BARTOL RESEARCH FOUNDATION W. F. 0. SWARN, DIRRCTOR
THE
LATITUDE
EFFECT M.
A.
OF COSMIC
RADIATION
*
POMRRANTZ
During the course of a program of cosmic-ray investigations conducted in India, absolute intensity measurements were obtained at two stations on the ground. The latitude effect at low altitudes is defined JJ(W where N(XJ is the intensity at by the relationship, L = 1 - N(XJ X > 40” and N(X2) is the intensity at low latitude XZ. Near sea leve1 the latitude effect with respect to 18” N. in India is L = 8.8 f 0.6 per cent, and at an altitude corresponding to 567 mm. of Hg, at 23” N., it is 13.1 & 0.6 per cent. The latitude effect does not vary rapidly with interposed absorber thickness. Vertical G-M counter trains yield approximately the same latitude effect as ionization chambers throughout most of the atmosphere. * Assisted by the Joint Program of the U. S. Office of Naval Research and the U. S. Atomic Energy Commission. HALL
EFFECT
IN METALLIC
THORIUM
*
J. H. BODINB
Complete understanding of thorium oxide electrolysis requires knowledge of the electronic. processes both in thorium oxide and in metallic thorium. Hall data for neither of these substances exist in the literature at present and work is in progress at Bartol to determine these quantities. Results for thorium metal have been obtained ; the material shows normal Hall effect, signifying conduction by negative carriers rather than holes. The value of the Hall coefficient is in line with that for common metals. Two specimens yield values 12.5 X lO-l2 and 10.5 X lO+, volts-cm-amp-l-gauss-l, respectively. * Assisted SHORT
by the U. S. Office of Ordnance Research. TIME
POLARIZATION
STUDIES
IN THORIUM
OXIDE
CRYSTALS
*
W. E. DANFORTH
As reported formerly, passage of smal1 currents through thoria crystals results in rapid growth of polarization potential, the polarization decaying when the applied current is interrupted. A wide range of time-scale is involved in this phenomenon: hours are required before equilibrium is reached, yet the initial effects are so rapid that oscillograph observations are required to determine the initial rise. Such 5’5
THE
LATITUDE
EFFECT M.
A.
OF COSMIC
RADIATION
*
POMRRANTZ
During the course of a program of cosmic-ray investigations conducted in India, absolute intensity measurements were obtained at two stations on the ground. The latitude effect at low altitudes is defined JJ(W where N(XJ is the intensity at by the relationship, L = 1 - N(XJ X > 40” and N(X2) is the intensity at low latitude XZ. Near sea leve1 the latitude effect with respect to 18” N. in India is L = 8.8 f 0.6 per cent, and at an altitude corresponding to 567 mm. of Hg, at 23” N., it is 13.1 & 0.6 per cent. The latitude effect does not vary rapidly with interposed absorber thickness. Vertical G-M counter trains yield approximately the same latitude effect as ionization chambers throughout most of the atmosphere. * Assisted by the Joint Program of the U. S. Office of Naval Research and the U. S. Atomic Energy Commission. HALL
EFFECT
IN METALLIC
THORIUM
*
J. H. BODINB
Complete understanding of thorium oxide electrolysis requires knowledge of the electronic. processes both in thorium oxide and in metallic thorium. Hall data for neither of these substances exist in the literature at present and work is in progress at Bartol to determine these quantities. Results for thorium metal have been obtained ; the material shows normal Hall effect, signifying conduction by negative carriers rather than holes. The value of the Hall coefficient is in line with that for common metals. Two specimens yield values 12.5 X lO-l2 and 10.5 X lO+, volts-cm-amp-l-gauss-l, respectively. * Assisted SHORT
by the U. S. Office of Ordnance Research. TIME
POLARIZATION
STUDIES
IN THORIUM
OXIDE
CRYSTALS
*
W. E. DANFORTH
As reported formerly, passage of smal1 currents through thoria crystals results in rapid growth of polarization potential, the polarization decaying when the applied current is interrupted. A wide range of time-scale is involved in this phenomenon: hours are required before equilibrium is reached, yet the initial effects are so rapid that oscillograph observations are required to determine the initial rise. Such 5’5