Cosmic-Ray Experiments at High Altitudes over a Wide Range of Latitudes

Abstract

A number of experiments made in a B-29 on the properties of cosmic rays are herein reported. These include the latitude effect of the following, performed along the 80th geographic west longitude from 64° geomagnetic north to the geomagnetic equator, all at a constant pressure altitude of 30,000 ft. (3.10 m of water equivalent): (1) Intensity at the vertical without and with lead absorber; (2) intensity at 45° West and 45° East both without and with lead absorber; (3) total ionization intensity; (4) extensive showers. Also measured at 48° North and at the geomagnetic equator were the following: (1) Zenith angle effect both without and with lead absorber; (2) intensity vs. air pressure without and with lead; (3) extensive showers vs. air pressure; (4) local showers. In addition to the above the variation in azimuth of the cosmicray intensity was measured with the various telescopes tipped at 22i°, 45°, and 67i° to the vertical at an elevation corresponding to 2.35 m of water equivalent at the geomagnetic equator. Two lead thicknesses were used, 10 and 20 cm, inserted between the counter trays. These experiments throw new light on the nature of the primary radiation and on the interaction of the primary particles with the matter through which they pass. ! z=o* Z«48* Z»67.5* -5 J -« J eo CM PB

Effect of the troposphere on surface neutron counter measurements

“…4 He 2+ is produced when a neutron interacts with 10 B, and the doubly charged helium atoms are detected in the proportional counter. In an early comparison, ionisation chambers and the new neutron counters were flown together on an aircraft to calibrate the neutron counter (Simpson, 2000;Biehl et al, 1949). Figure 2a shows ionisation rate and neutron counts at 9km, over a range of geomagnetic latitudes (Simpson, 2000).…”

“…Figure 2. Neutron counter-ionisation chamber comparisons a) Calibration of one of the first neutron counters at 9km, over 10-50º geomagnetic latitude, after Simpson (2000) and Biehl et al (1949) b) Calibration of neutron monitor to ionisation chamber (IC) for 1953-1957 c) Time series of Cheltenham (USA) ionisation chamber (Ahluwalia, 1997) and Climax neutron monitor.…”

On the Production of Mesons by Primary Cosmic Rays

“…In the case of w-*ix decay, in which all /x-mesons emitted by a 7r-meson at rest have the same range, 18 18 (1)…”

Sur les traces isolées produites par les rayons cosmiques dans les émulsions nucléaires

“…métrie a été faite par plusieurs auteurs et approfondie par T. H. Johnson [1]. Plus récemment, des mesures minutieuses, faites par Biehl, Neher et Roesch [2] donnent pour la dyssymétrie Est-Ouest avec et sans absorhant, les valeurs données dans le tableau suivant :…”