Parameters of track structure

Linear energy transfer (or collision stopping power) and energy straggling along the tracks of charged particles are both relevant to the effectiveness of ionizing radiation. Energy straggling is the dominant aspect whenever one is concerned with small energy depositions ( < 1 keV) and a correction to L E T is necessary in these cases. The correction term and its relation to the spectrum of energy transfers in primary collisions is derived. Other parameters of track structure are discussed, and an analysis is mentioned which can substitute the Landau- and Vavilov-theory in the analysis of the collision spectrum

On the Number of Clumps Resulting from the Overlap of Randomly Placed Figures in a Plane

When two-dimensional figures, called laminae, are randomly placed on a plane domains result that can either be aggregates or individual laminae. The intersection of the union, U, of these domains with a specified field of view, F, in the plane is considered. The separate elements of the intersection are called clumps; they may be laminae, aggregates or partial laminae and aggregates. A formula is derived for the expected number of clumps minus enclosed voids. For bounded laminae homeomorphic to a closed disc with isotropic random direction the formula contains only their mean area and mean perimeter, the area and perimeter of F, and the intensity of the Poisson process