FISSION PRODUCTS IN THE ATMOSPHERE
AND IN RAIN
P, K. KURODA, PENTTI KAURANEN,* B. D. PALMER,
K, K. MENON, and L. M. FRY
University of Arkansas, Fayetteville, Arkansas
ABSTRACT
The concentrations of sr, sr, “°Ba, ‘!ce, and ‘Ce in individual
samples of rain and snow have been measured radiochemically at
Fayetteville, Ark., for the past several years. Certain features of the
isotopic ratio data may be explained as being due to atmospheric fractionation of nuclear debris taking place on a global scale. High con-
centrations of Mn, '*4Sb, and '°Sb were observed in the air-filter
samples collected in connection with Project Star Dust in 1962 and
1963. The '5sp/®sr ratio in 1963 samples was found to correspondto
values reported for the production ratio in thermonuclear explosions,
but some samples collected at high northern altitudes in 1962 showed
an excess of ‘Sb. It appears that 25Sbh was partly produced through
second-order neutron capture in '%sgb. A sudden increase of “Mn con-
centration was observed in April 1963 at an altitude range of 30,000 to
35,000 ft.
INTRODUCTION
Levels of sr, Sr, “Ba, ‘Ce, and '“4Ce in individual samples
of rain and snow have been measured radiochemically at Fayetteville,
Ark., during the past several years. A set of Project Star Dust high-
altitude air-filter samples was received by the University of Arkansas
in the fall of 1963, and a study on the distribution of fission products
and a number of nonfissiogenic nuclides such as *4Mn and '4Sb has
recently been undertaken.
|
*Present address: Department of Physics, University of Helsinki, Helsinki,
Finland.
602