"This is the third quarterly report on Task II dealing with Methods Development for Radio-Tracing of Coal Product Hydrocarbons With Tritium. The problem of accurate low-level tritium assay for tagged hydrocarbons has been resolved and attention is now primarily directed at the questions of tritium mobility and radio-chemical purity in tagged tracers."

"Muon capture rates have been measured in a large number of the heavier elements in recent years. The amount of data available on the light elements, however, is scant. It would seem that lifetime measurements of muons in light elements would be of particular interest with regard to understanding the nuclear structure and determining the strength of the weak interaction. Furthermore, only one previous measurement of the muon capture "'isotope effect" has been done, that being for chlorine isotopes. In view of these considerations, the series of muon capture experiments reported in this paper was undertaken."

" A reliable, efficient and economical method is needed to remove radioactive halogens such as iodine and bromine and particulates from air in many atomic energy installations. One method we have developed which is particularly suited to reactor containment vessels or other large confined areas is foam containment. In this method an ether lauryl sulfate foam containing an iodine reactant is generated, rapidly filling the entire containment volume. This provides a tremendous surface area to which the encapsulated gases and particles can diffuse and be removed."

"Research in thermal contact resistance at MIT and advances made during the past year are summarized. The problem of predicting cortact resistance is examined in an analysis of a model for the contact which relates the geometry of actual surfaces in contact to the contact model, and a deformation analysis which relates the contact geometry to the load carried by the surfaces. Experimental procedures are described and are applied to two stainless steel surfaces in contact and to W and graphite surfaces in contact. A significant result is that a surface may be described by two measurable parameters which may be combined with two such parameters of any other surface to completely determine the geometry of the interface if they are placed in contact. It thus remains to construct a device which will readily measure these two parameters."

"Mesic decay of hyperfragments is discussed systematically on the basis of a previous model for hyperfragments. The general formalism for the two-body and three-body mesic decay was developed. The polarization-direction correlation and the angular correlation for the two-body and the three-body decays are discussed together with the decay probability. The formalism was developed so as to include the isotopic spin selection rule ( DELTA I = 1/2 and 3/2) for the mesic decays. The theory was applied especially for the low mass number hypergragments where it was found that the branching ratios of the two-body and the three-body mesic decays of /sup 3/H/sub i and /sup 4/H/sub i, (/sup 3/ H/sub i yields /sup 3/He + i/sup -/)/(/sup 3/H/sub i yields D + p+ pi /sup -/) and (/sup 4/H/sub i yields /sup 4/He + pi /sup -/)/(/sup 4/H/ sub i yields /sup 3/H + p + pi /sup -/), could be used for the determination of the spins of both hyperfragments. The fraction of the p-wave decay rate for the free LAMBDA decay obtained from the reaction /sup 5/He/sub i yields /sup 4/He + p + pi where the decay proceeds through two-resonant states (p/sub 3/2/ and p/sub 1/2/) …

"An investigation was made into the various processes for the fixation of mixed fission products as solids in order to determine the extent they could be utilized as heat sources for thermoelectric generators. Generators of up to ten watts can be designed and built with state-of-art'' thermoelectric materials and mixed fission products soon to be available from the ldaho Falls calcination pilot plant. Mixed fission products from other processes and plants to be on stream'' in this decade will be capable of fueling practical generators into the kilowatt range using thermoelectric materials available in the same time period. A survey was made on current research and development efforts on waste fixation processes. Studies showed that a wide range of power densities (from 0.002 to 0.2 watts per cubic centimeter) will be available from calcined fission product wasted. An experimental program for the consolidation of low density, Idaho Chemical Processing Plant alumina type wastes is reviewed. Preliminary results indicated that densification factors of three to four are readily obtainable for such wastes."