A Digital Equipment Corporation PDP-14 Industrial Programmable Controller was employed to provide automatic, closed-loop control for an explosive pellet manufacturing system at Mound Laboratory. Programmable controllers allow the application of sophisticated and flexible control, through programming. Advantages of the PDP-14 controller are ease of installation and maintenance, capability for modular expansion, and immunity to electrical noise. Safety requirements were met by using new techniques for adapting electrical equipment to a hazardous environment and by locating the PDP-14 remotely outside the explosive area. Another advantage of the new explosion proofing (EP) methods/equipment was that they produced a minimum of clutter on the controlled explosive pellet manufacturing system.

A unified Hamiltonian approach to the theory of nonlinear interactions among waves and particles is discussed. The unifying feature of the approach is a generalization of the concept of pondermotive force. The usual method of time averaging is replaced by a canonical transformation. The transformation is designed to eliminate the terms in the Hamiltonian of a particle which are linear in the wave potentials, replacing them with bilinear terms at combination frequencies. An oscillation center approach is illustrated by deriving a compact general formula for the three-wave coupling coefficient in collisionless plasma. (MOW)

A small man-portable neutron detector was constructed using 18 /sup 3/He proportional counters arranged in three layers within a polyethylene moderator. Each counter is 25 mm in diameter by 340 mm long (sensitive length) and is filled with highly-purified /sup 3/He to a pressure of 400 kPa (4 atm). Efficiency measurements were made using a /sup 252/Cf neutron source. Detailed calculations of the detector efficiency were done using the TART Monte Carlo transport code. Calculations and measurements were compared for several source/detector configurations.