2006-2007 Colloquium Series

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NAU Physical Sciences (Bldg 19, Rm 321), Monday, 12 February 2007, 4:00 PM
(Refreshments at 3:45pm)

From Nuclear Tests to Cosmic Bombardment

Keran O'Brien
NAU

Abstract

Radiation propagation has evolved from pen and pencil studies using tables of cross sections and of mathematical functions to large and complex codes written and maintained by highly-skilled teams. The author's pilgrimage through this process; from his pencil-and-paper days while on Eniwetak Atoll in 1956 to spherical-harmonics transport codes, the use of Sn and Monte Carlo codes, to an analytical transport code used for the calculation of cosmic-ray propagation through solar-system atmospheres ranging from Earth to Titan, and finally to a Monte Carlo transport code to treat cosmic-ray transport through the heliosphere will be described. The applications of these calculations include the radiation from radioactive fallout, beta-ray transport, accelerator shielding, hospital physics, cosmic-ray ionization, cosmogenic isotope production, the radiation dose to air crew, radiation dose to space crew and cosmic-ray fluxes to spacecraft. Some examples of the results of these calculations will be given.

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