Abstract: A process and apparatus for subjecting a mixture of two types of electrically charged particles to intense physical contact through a pneumatic transfer modified by turbulent flow and path interruptions to produce surface electrical charges on the particles, and separating the charged particles to recover particles having the same charge. Seeding with a recoverable catalyst may be used as well as forming the path of the mixture from one of the two types of electrically neutral particles. The path interruptions may be sudden directional changes, circuitous paths, baffles, induced vortices and other mechanical apparatus.

Abstract: The invention relates to a process for depositing I-125 on a substrate which comprises contacting a predetermined surface area of substrate with Xe-125 gas, whereby the Xe-125 decays to I-125 and the I-125 in turn deposits as a solid on the surface of the substrate, the contact being for a time sufficient to deposit at least about 1 microcurie of I-125. I-125 is thereby deposited in a relatively uniform amount over the surface area of the substrate. The substrate is then assayed to determine how much I-125 has been deposited. The substrate is then divided into pieces of measured surface area, each piece therefore containing a measured amount of deposited I-125, and each piece can then be used in the manufacture of an I-125 source.