Quarterly updates on nuclear chemistry, bio-organic chemistry, general chemistry, chemical engineering (process chemistry).

Our aerosol program employing monkeys has been initiated. A plutonium oxilate solution was introduced into the trachea. Preliminary results of the fecal and urinary determinations appear here.

Progress report on biological studies of radiation effects, metabolic properties of various materials, health chemistry, health physics.

A preliminary study of positive pion production from proton-nucleus collisions revealed that positive pion production cross sections agree more favorably with a Z 2/3 variation than with a variation proportional to the atomic number. A similar study on negative pion production has shown that negative pion yields from proton-nucleus collisions tend to vary in proportion to the number of neutrons in the nucleus. As a result an experiment was performed to investigate if there is a significant change in positive pion production with changing atomic number at two lower pion energies.

An empirical relation is presented which represents a boundary between no vacuum sparking and possible vacuum sparking. Metal electrodes and r.f. or d.c. voltages are used. The criterion fits several orders of surface gradient, voltage, gap, and frequency. Current due to field emission is considered necessary for sparking but in addition, energetic particles are required to initiate a cascade process which increases the field emission currents to the point of sparking. An elementary cascade process is outlined, but the data upon which it is based is not fully stated.

Diffusion equations for a cascade shower which include an energy cutoff and energy parameters for each particle have not previously been studied. In this paper it is found that an inclusion of both permits collision loss to be represented as a discrete process by modifying the differential radiation cross section.

Certain isotopes in the region of the heaviest elements have been produced by cyclotron and pile bombardment techniques, and their nuclear decay properties have been investigated. The orbital electron capture decay of At210, At211, Np234, Np235, Pu234, Pu237, and Am242m has been studied and decay schemes have been proposed. In addition, the alpha spectra of Po211, At210, and At211 have been observed.

One of the oldest properties of electrons is their emission of x-rays (discrete and continuous spectra) when impinging on matter. Cloud-chamber tracks show light ionization, and considerable multiple scattering, except for fast electrons. Tracks are long and range indefinite.