The production of D/sup -/ by multiple charge-transfer collisions of a D/sup +/ beam in a cesium-vapor target is considered for D/sup +/ energies above 300 eV. The cross sections relevant to D/sup -/ formation are obtained by a least-squares fit of three-charge-state differential equations to experimental yield curves. Implications for production of intense negative-ion beams are discussed, and speculations are made about extrapolation to lower engeries.

Studies were made of the process characteristics of a plant to decontaminate tritiated water using dual temperature exchange with VH/sub 2/. Feed to the plant consists of 300 kg/day on water containing 1 Ci/kg of tritium. A reference design was developed based on a decontamination factor of 10/sup 2/ and 10 kg/day of enriched product. This design requires a total of 48 ideal separation stages, 22 stages in the enriching section and 26 stages in the stripping section. Only low grade heat is required for the heating cycle and a relatively small (12 ton) ice machine is required for the cooling cycle. A total plant inventory of approximately 10 tons VH/sub 2/ is required. A mechanical design of the dual temperature stage complete with all heat transfer surfaces and flow diverters was devised and modeled. Since the process involves periodic swings in temperature between 0 and 60/sup 0/C, a substantial portion of the operation is expected to be in unsteady state transition from one state to another. A two-step experimental program has been presented: the first step consists of a single stage unit, i.e., one hot bed and one cold bed operating in a simple closed loop. The second stage …

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Chemical explosives may become a key element in many of the in situ energy and mineral recovery methods under development. The potential role of explosives in deep rock mining for resource recovery is discussed. Several energy and mineral recovery programs described are an outgrowth of the Plowshare Program and Explosives R and D conducted as part of the AEC/ERDA mission at Lawrence Livermore Laboratory. Several important aspects of the use of explosives in deep rock mining are reviewed. First, the status of knowledge of deep rock fracturing to create permeability underground is discussed. Completely contained blasting has not been a widely applied tool used in the mining industry. It is concluded that data available on deep rock fracture is minimal and that the mechanisms that control the processes must be understood before technical and economic feasibility can be established. The unusual problems in the selection of an explosive or blasting agent for deep rock applications including emphasis on the functioning at depth and safety aspects are also discussed. Finally, a brief review of similar activities within the U.S. is given.