From abstract: "This report describes methods used for radiochemical analysis of fission products most used in the Experimental Biology Section. The report includes methods of analysis of Sr89, Ba140-La140, Zr95-Cb95, Ce144-Pr144, and Y91 by standard chemical procedures. In addition, a method of analysis by use of an absorption curve is described in some detail for Zr95-Cb95 mixtures. The absorption curve method makes possible rapid determination of percentage composition of a mixture of isotopes with a minimum of chemical manipulation by utilizing the differences in absorption characteristics of the emitted rays."

Abstract: The counting accuracy of the Chicago Scalers, Models 961A and 961B, is a function of the bias setting of the limiter (V2). this report gives quantitative data supporting this thesis. A method of making bias settings is suggested. These tests were run at the suggestion of Mr. V. C. Hanson.

From abstract: "A sensitive method for measuring the intensity of weak neutron sources by measuring induced Mn56 beta activity after concentration by a Szilard-Chalmers process has been developed. The practical detection efficiency for Ra-Be neutron is 7.8%; the procedure is capable of detecting a neutron intensity of about one neutron per second."

From introductory paragraph: "The study of the counting techniques of gamma-emitting radioisotopes is of a great deal of interest to workers in the field of radiochemistry. Of particular interest to the long-lived gamma emitting isotope of yttrium which is commonly prepared by a deuteron bombardment of strontium and is reported to decay by K-capture. This isotope, which is of interest in the fields of biochemistry and metallurgy was tentatively assigned to mass 86. Since a 2.0 hour activity was observed from a neutron irradiation of yttrium, the assignment was considered fixed. Subsequent work indicated a possibility of a long-lived gamma emitting activity arising in the fast neutron irradiation of yttrium. The published data did not agree with theoretical calculations as to the possibility of these two activities being isomers. This work was undertaken to study the characteristics of the radiations from the isotopes; to have data available on the long-lived activity; and, to attempt to fix the mass assignment."