Abstract: "The analysis of an immobilized plasma is here extended to the case where the geometry is cylindrical rather than Cartesian. (This report, UCRL-4439 (Rev, 4 constitutes Part II of the report series (UCRL-4466, Parts I, III, and IV) dealing with this general problem.)"

Radioactive decay data are used to calculate the atomic masses of the heavy isotopes, A> 203. The four radioactive families are then connected by means of neutron binding energies known from reactions on various isotopes. Finally all the masses are collectively adjusted for the best fit with mass spectrographic information available in this region. The masses so calculated are presented. Differences between masses of isotopes are estimated to have an of (plus/minus) 0.00020 mas units or about 200 Kev; the position of the masses taken collectively is in doubt by about 1.5 Mev.

The thermal decomposition of the higher oxides of praseodymium and americium have been investigated.

A two-group approximation of the fission ratios and Pu production in an infinite hollow matrix is developed

Positive and negative mesons produced in a common target in the cyclotron are received in two photographic plates. In the magnetic field of the cyclotron, negatives are deflected to one plate, positives to the other. The mesons must pass through an absorber before entering the plates in order to be observable.