Two IBM-704 codes have been written which are auxiliary to the Bevatron orbit code BOC. The first, BEFCYF, interpolates among tabulated values of the median-plane magnetic flux density of the Bevatron to produce an equivalent array of values in a form appropriate to BOC. The second, DBDT, produces azimuthal derivatives of the fields produced by BEFCYF. The internal operation of BEFCYF and DBDT is described, and instructions for their execution are given.

This paper describes the method developed and the results obtained in an extensive program of measurement of the masses of charged pions. Measurements were made of the total ranges in nuclear track emulsion and the momenta (obtained from the curving of the particle trajectory in the magnetic field of the 184-inch cyclotron) of pions and protons of nearly the same velocity.

The guiding center motion and the adiabatic invariants of charged particle trajectories in electromagnetic fields are treated in this review. General and specific theories of charged particle motion are also reviewed.

We have preliminarily reported the interpretation of our experimental results that the intensity of the spectrum at the maximum energy was zero. But, as reported in the second paper UCRL-1261 we found that the results may also be fitted to a different spectrum with finite intensity at the maximum energy. Quite recently, however, the most probable value for the mass of the p-meson has been revised by two independent groups based on two different experiments.

The root locus method of the treatment of stability problems in the field of servomechanisms is briefly summarized. A simple mechanical instrument of the analogue type (a summing device) containing no gear mechanisms, and designed to do most of the numerical work of the root locus method, is also described.

The angular distribution of charged x mesons produced by 300 <x> 30 Mev neutrons on C12 and Be9 have been studied. An analysis of the kinematics for meson production in a nucleon-nucleon collision indicates a fairly well defined center-of-mass system.

Plus-minus ratios for pion production by 340-Mev proton bombardment were measured at 13 Mev, 18 Mev, and 42 Mev with the use of the spiral orbit spectrometer.

In an effort to gain information on the nature of the photon-meson and photon-nucleon interaction, a study of the artificial production of mesons by photons has been made at the Berkeley synchrotron. The major effort of this research was concentrated on a measurement of the energy and angular distribution of u+-mesons produced when the photons strike a target of liquid hydrogen. Detection of the mesons is accomplished electronically by the technique of delayed coincidence.

This report was prepared at the request of the Subcommittee on Radiochemistry of the Committee on Nuclear Science of the National Research Council as a contribution to a proposed master file on the radiochemistry of all the elements. All known material on the radiochemistry of thorium is included in this report.

This revised version contains material published in the two years since the original report was issued in January 1960. The report covers the history of the discovery of fission, fission theory, and the probability of fission. It discusses the distribution of mass in fission, the distribution of nuclear charge in fission, kinetic energy of fission fragments, and the role of neutrons and gamma rays in fission.