Dr. C. Dunham onden July 25, 1957 Such a crystal has been proved satisfactory in the proposed type of application by Marinelli and Miller at Argonne National Laboratory. It is extremely important that the crystal and the materials used for encasing it be free from radioactive contaminants. A suitable crystal can be fabricated by the Harshaw Company. A stand such as is used with a portable x=ray machine would be used to support the crystal assembly. b) Two, One hundred channel gamma spectrum analysers. Conference with Drs. Kuper, Higginbotham and Chase of the B.N.l. Instrumentation Division indicates that this type of instrument would be satisfactory for the type of analysis contemplated. These instruments are currently being fabricated at the Technical Measurements Company, New Haven, Connecticut, for B.Nele and are considerably less axpensive than the two hundred fifty-six channel type analyzer in use at Argonne National Laboratory. In view of the remoteness of the locale of examinations and consequent difficulties of getting repair work done within a reasonable period of time it was alse recommended that two of these analyzers be taken along, c) In order to insure sufficiently low background radiation for such analyses a room with steel walls of at least 4" thickness is deemed advisables Mr. John S. Medd, Dr. Je Se Robertsen alll myeelf of BeNeLe have contacted officials at the Navy Yard, New York, in regard to fabrication of such a room with the following results. We were informed that a barbette from a cruiser is to be removed in the near future for serapping purposes. This cylindrical barbette eould be cut so that four curved sections, 6' high and 6" thick would form the sides of a chamber about seven feet across. Two, two inch thick steel plates could be secured both on the top and bottom of the chamber to afford overall shielding of four to six inches of steel. A door of adequate size of 4 inches steel thickness would be made for access, The sise of this room would be adequate for the purposes and the thick steel Walls, floor and ceiling would insure a low background. Necessary openings for electrical lines could be made, Subject te Navy appreval, this chamber could be fabricated at the Naval Shipyard at New York and shipped to Pearl Harbor via one of the Navy vessels en route there. At Pearl Harbor the room could be assembled and placed on board the tank deck of the LST to be provided. Cranes at Pearl Harbor can easily handle the transfer to the LST, Two small dehumidifyers would be needed, one in the steel room to make the subjects more comfortable during measurements and one in a small wooden room to be built adjacent to the steel room to protect the analyzer against high humidity. The power source aboard the LST will be adequates Upon completion of the operation the steel room would be stored at Pearl Harbor Navy Yard for future use. P1819gqh