Lower, b. DOG, BASY and GEORGE Flowering Tradescantia plants were exposed to tion intensity wos sufficiently low to shots at distances where the predicted radia be analyzed, Tradescantia were also produce chromosomal aberrations which could to measure the integrated dose placed in drone aircraft for each of the three shots of radiation during the cloud pass. The estimates of dose based on the study of rated film, chromosomes agreed well with the preliminary reports of the calib c, were The Tradescantia system was successful and the results obtained thymus-spleen consistent and agreed well with the measurements made by the mouse system, ia and The closest agreement between the dose ostimates based on Tradescant those based on calibrated fila was obtained in the drone aircraft experiments where the dose rate was lowest. 8. NUCLEAR RADIATION DEPTH DOSAGE STUDIES a. Depth dose estimations were madc to investigate the quality of the nus clear radiation, The specification of the quality of a beam of jonizing radiation of whatever source is a major preblem in clinical. radiology. The conventional unit is the half value layer C(HVL), and in the case of X-ray therapy the conventional technique involves the use of phantoms constructed from material of unit density. The ability ta specify the quality of the radiation from a nuclear weapon is intimately related to the problem of the exporimental production of radiation injury, since it is possible that cnergy dependency and dose distribution may be important limiting factors in determing the type of injury that results, b, Spherical lucite phantoms were displayed on EASY and GEORGE shots. each case the nearest group of phantoms was Lost duc to flying debris, In The ioniza- tion chambers and film packs were recovered from all the others and were in good condition for study. ce, Swine phantoms which resembled the shape and bulk of the torso of the swine, or a man, were exposed on EASY and GEORGE shots. All were recovered and the film packs contained in them are being processed, d. brated film. The data have not been analyzed from the phantoms that contained caliIn those that contained ionization chambers, it wis found that the HVL using lucite (density slightly greater than unity) exceeded 20 centimeters. This finding indicates a very energetic composite radiation, the mean effective energy of which was weld in excess of 1.0 Mev. Jt was mentioned above that the biolopical ‘ ‘2 Dente i > Tk estimates of dose at a given distance were consistently lower than that given by