This report follows and experiment that was performed to determine the visual efficiency of a phosphor when bombarded by alpha particles.

The following report describes how to obtain traces of cadmium using dithizone as a reagent.

Monthly report of the U.S. Geological Survey's trace element investigations including an outline of field work, laboratory work, and staff activities that have been completed or are in process.

Abstract: Magnetic susceptibilities per gram atomic weight of elements 92 to 95 in most of their oxidation states were measured at 20°C on 0.1 ml of solution which was 0.005 to 0.09M in heavy element. The values obtained (all paramagnetic) in units × 106 were: U(IV), 3690; Np(VI), 2060; Np(V), 4120; Np(IV), 4000; Pu(IV), 1610; Pu(III), 370; Am(III), 720. The results could be interpreted only on the basis of electronic configurations 5fn, even though susceptibilities were generally lower than the theoretical values and lower than experimental values for corresponding lanthanide 4fn cations. The lower values should be expected as a result of the Stark effect produced by electric fields of anions and of water dipoles. Failure of the Russell‐Saunders approximation to the coupling between electrons may account for some of the error in the theoretical calculations. That the susceptibilities of Pu(III) and Am(III) are manyfold lower than those of Sm(III) and Eu(III), respectively, is attributed to wider multiplet splitting in the actinide atoms.

Summary: The activity coefficient of Pu(Cl04)4 was measured in perchloric acid solutions. The procedure used was to measure the extraction of the neutral plutonium(IV)-TTA chelate into benzene-TTA solutions at different perchloric acid concentrations. Equations are presented which show the relation of the extraction coefficients, obtained in the above manner, to the activity coefficient of plutonium(IV) per-chlorate. The activity coefficient of Pu(Cl0~)4 is similar to that of a strong acid, e.g., perchloric acid, in that its value increases rapidly when the perchloric acid concentration becomes greater than 2M. The distribution coefficient of TTA between benzene and aqueous perchloric acid solutions was found first to decrease slightly and then to increase two fold as the perchloric acid was varied from 0.01 to 6M. The activity coefficient of the uranous-TTA chelate in benzene was calculated from the results of solubility measurements. The values of the activity coefficient of UK4 are,within experimental error, identical with the values of the activity coefficient of TTA itself.

An effort to develop a control on the air velocity at the door opening of a fume hood.

Construction of a linear accelerator which increases the energy of protons from a 4 Mev Van de Graaff injector to a final energy of 31.5 Mev.

From note: "Report discussing the history of the research of potassium 40 and its radioactivity, as well as the author's own investigations into the isotope."

Discussing the Majuba Hill mine, located 20 miles northwest of Imlay, Nevada, and consisting of approximately 4000 feet of workings on three levels.