Passage of Neutrons through Matter

Abstract

THE discovery by Dr. J. Chadwick¹ of strong experimental evidence in favour of the existence of neutrons of mass approximately that of the proton makes it imperative that as many lines of attack as possible on the problem of determining the nature of this particle be developed. Thus, it is clearly very important to determine the nature of the field surrounding the particle. In order to investigate this, the simplest method is to examine the interaction of a neutron with other material particles such as atomic electrons. Thus, the measurement of the number of ions produced per centimetre by neutrons of different velocity should lead to a method of determining the field. It has therefore been thought of interest to give a preliminary account of the results of theoretical calculations of the behaviour of possible neutrons in this respect.