attributed in part to the hydrofynanic effect, whieh results in an enhancement ef the game radiation. This effect is caused by the passage of the shock front, through the detector station, resulting fs en inhomogeneity of the air between detector anf refiating source. Section 1.3.4 gives a simplified treatment ef the hydrodynamic effect. Measurements were made during Operation Castile by the U. 8. Amy Signal Engineering Laboratories to determine the empirieal relation between yield and hydrodynamic enhancement (Reference 2). Some high- yielé Castle devices provided data points; however, it ws felt that additional data were needed at a number of suitably speced points for various yields and types of muclear devices to determine more valid scaling laws. he present scaling laws for initial gaume radiation frém high-yield thermonuclear devices vere based on data from relatively low- yield fission devices (1 to 500 kt), a few data points from Operation Ivy, ané the sperse data from Castle. Initial ganma radiation appeared to be ef little significance compared to damnge caused by blast and thermal effecta. ‘Residual gana refiiation is here defined as that which reaches the detector 3 seconds or more after the time of detonation. Residual gan exposure measurements have been made by various organisations at previous test operations (References 2, 3, 5, and 6). During Operation Buster- dangle, the Signal Corps, in conjunction with MBS, meade residual game exposure measurementa of a 1-kt surface blast and a 1-kt weapon detonated et a dept: of 17 feet (Reference 7).-puring Seepotthe U. 8. army Signal Enet Leboratories made measurenents of residuel-gamma exposure resulting from