The Interaction of Configurations: sd−p^2

It does not seem possible to account for the presence of singlets below their triplets in two electron spectra simply from the ordinary exchange integrals. The exchange integrals seem to be essentially positive. It is shown that the matrix component of electrostatic energy connecting the 3s3d^1D with 3p^2^1D in Mg I is sufficiently large to account for the occurrence of 3s3d^1D below 3s3d^3D as observed experimentally. Analytic radial wave functions of the type developed by Slater are used in the calculation of the nondiagonal elements

Photoproduction of mesons and hyperons

The availability in recent years of increasingly energetic photon beams from particle accelerators has led to significant advances in the study of photon-nucleon interactions and the photoproduction of mesons and hyperons. This work also holds the promise of future contributions to better understanding of the nature of the strong interactions

Note on the Magnetic Moment of the Nitrogen Nucleus

Three lines of the group 2s2p^4^4P−2s^22p^24p^4D of N I have been examined for hyperfine structure. They were found to be single when examined with a Fabry-Perot interferometer, using a variety of plate separations. The line widths of two of the lines were measured. The absence of hyperfine structure is attributed to the small magnetic moment (μ) of the nitrogen nucleus. It is shown that, by using the results of Goudsmit, the measured line widths lead to an unusually low magnetic moment for the nitrogen nucleus, μ≦0.2(eh)/(4πMc). Under certain assumptions about the structure of the nitrogen nucleus, this low value of the magnetic moment leads to the conclusion that the neutron has a magnetic moment in the opposite direction from its mechanical moment and about one proton magneton in magnitude

Atomic Energy Relations. I

A simple method for the calculation of approximate energies of atomic levels is presented in this paper. It is based on the derivation of linear relations which express the unknown energy in terms of observed energy values of the atom and its ions. It is shown that the degree of approximation increases with the amount of experimental data available for use in the calculation and also how the best formulas can be obtained for each case. Several tables are given containing formulas for configurations involving s and p electrons. They are applied to the spectra of carbon, nitrogen and oxygen and the energy values so determined are compared with those known from observations. In an appendix the method of approximation is compared with the quantum mechanical perturbation method

Separations in Hyperfine Structure

The quantum mechanics conception of a spinning electron in an s state makes it probable that its interaction energy with a nuclear moment i is simply proportional to the average of is cos (is). Expressions for this average cosine have been obtained and applied to different examples. In more complicated cases it can only be said that the interaction energy is proportional to ij cos (ij), which makes the interval rule hold for hyperfine structure

The Electric Quadrupole Moment of In^(115)

Measurements of the lines λ7852 (5s6p^1P→5s6s^1S) are λ8241 (5s6p^1P→5s5d^1D) of In II show deviations from interval rule. These deviations are satisfactorily accounted for by the presence of a nuclear electric quadrupole moment which from the first of the lines is found to be Q=0.82×10^(−24) cm^2. No trace of lines due to In^(113) was found

Evidence for a Nuclear Electric Quadrupole Moment for Sb^(123)

Measurements of the hyperfine structure of the line λ5895 of Sb II by the use of a Fabry-Perot interferometer have shown that there are deviations from the interval rule in the case of the isotope with mass number 123. The hyperfine structure intervals of the ^3D_1 level of Sb^(121) (I=5/2) are found to be 0.6801 and 0.4832 cm^(−1). The corresponding intervals in Sb^(123) (I=7/2) are 0.4814 and 0.3603 cm^(−1). The error in these measurements is of the order of 0.001 cm. The observed ratio of the two separations gives 1.407 and 1.336 for the light and heavy isotope, respectively, whereas the corresponding ratios on the basis of the interval rule are 1.400 and 1.286. The deviation in the case of the light isotope is within the experimental error. The deviation for the heavy isotope, however, is a real effect which cannot be accounted for on the basis of perturbing effects of neighboring levels and must therefore be ascribed to the presence of an electric quadrupole moment of the nucleus of Sb^(123)

Nuclear Physics. A. Stationary States of Nuclei

[No abstract

Photographic Effects Produced by Cadmium and Other Elements Under Neutron Bombardment

It has been found that when a duplitized x-ray film has Cd placed next to it and is then surrounded by paraffin and exposed to a neutron source, the film shows blackening under the cadmium. Under these conditions the film also shows some general blackening which is rather weak. The neutrons used in these experiments were obtained by bombarding either Li or Be with about 10 microamperes of 1.2 Mev deuterons furnished by a cyclotron. There are, of course, also p-rays incident on the Cd and the photographic film, and it was necessary to establish the blackening under the cadmium as due to slow neutrons and not to these radiations