_a_/ 2~22 wo The experiments on effects of atomic weapons on materials and evel: of a skin simulant were carried out on shots Yellowwood and ‘Walnut. Approx imately 30 skin sinulant specimens in various configurations including bare and blackened unclothed samples, samples clothed with contact and spaced fabrics, and semples with various apertures were exposed. histories of the specimens were recorded, Time temperature In addition, recording calori« meters and radiometers were used to measure the thermel radiation incident at the station. The abletionand neutron vulnerability studies were carried out on shot Cactus. For the experiments on ablation of m:terial two specimens designed to determine the rate and depth of melting of a sphericcl surface were ex= posed on a 100 ft. tower so as to be within the fireball. These specimens contained instruments for measuring and recording the time history of the temperature of unprotected metal 2t various depths, specimen acccleration, latefireball overpressure, and shock arrival time. Two additionel speci- mens rigidly spaced 10 feet apart and risidly connected were placed on the ground at e distance of 250 fect to measure the speed of sound inside the fireball. These specimens contained transducers ani recorders for measuring the time of arrival of weak shocks from a series of small explosions set off at suceessive times after zero time. From these ieasurements it was hoped to calculate a time history of the ges temperature of the fireball. As yet no results are available from the ablation and neutron studies ;(oreo/o0g gg pce eSH.