An apparatus for use with a neutron source for producing reaction-product nuclei from reactant nuclei includes a plurality of reactant nuclei and a plurality of moderating nuclei. The reactant nuclei and the moderating nuclei are configured to increase the probability of neutron capture by reactant nuclei to achieve enhanced ratios of neutron capture by reactant nuclei to neutron source neutron production. Moderating nuclei and neutron reflection are used to minimize neutron leakage. Temperature control, including cryogenic temperature control, may be used to enhance the rate or probability of reactant nuclei neutron capture. The reactant nuclei may include molybdenum-98 and reaction-product nuclei may include technetium-99m.

The present invention relates to a method of preparing a gas coolant for the direct cooling of a unit operation under a fixed heat load from its normal operating temperature (e.g., 300 F. and above) to a lower temperature (e.g., below 100 F.) in order to allow for maintenance or other non-routine work to be carried out in said unit operation.

A flexible polymeric tube comprising: an outer tubular wall layer comprised of a thermoplastic propylene-based elastomer (PBE) material, and, an innermost tubular layer comprised of a thermoplastic ethylene-based olefinic material.

Methods for generating a purified catalyst are provided. The method includes performing a reaction in a reaction vessel to generate a liquid catalyst and reaction products, purging the reaction products using an inert gas to form a purged catalyst, freezing the purged catalyst in the reaction vessel, and applying a vacuum to the reaction vessel while the purged catalyst thaws, wherein the vacuum removes residual reaction products to form a purified catalyst. Systems for generating a purified catalyst and a purified catalyst are also provided.