X-RAYS: Electromagnetic radiations of high energy having wave lengths shorter than those in the ultraviolet region. YIELD (OR ENERGY YIELD): The total effective energy released in a nuclear (or atomic) explosion. It is usually expressed in terms of the equivalent ACKNOWLEDGEMENTS tonnaye of TNT required to produce the same eneryyrelease in an explosion. The total energy yield is manifested as nuclear radiation, thermal radiation, and shock (and blast) energy, the actual distribution being dependent upon the medium in which the explosion occurs (primarily) and also upon the type of weapon and the time after detonation. their exThe author is deeply grateful to the following for in this pampert advice and assistance. Any shortcomings the author. of ty sibili respon phlet, however, are solely the ll for Appreciation is expressed especially to Dr. Roy D. Maxwe her for s Meyer J. Edith his generous assistance and to Mrs. typing of the manuscript. Atomic Energy Commission Mr. Robert E. Allen Dr. H. David Bruner Dr. Charles L. Dunham Mr. Richard Hamburger Dr. John H. Harley Mr. Donald W. Hendricks Mr. Joshua Z. Holland Mr. Alfred W. Klement, Jr. Dr. Roy D. Maxwell Mr. Tommy F. McCraw Colonel MacPherson Morgan Captain Benjamin R. Petrie, USN Mr. James E. Reeves Mr. Otto H. Roehik Dr. Donald M. Ross Mr. Carl G. Welty, Jr. Mr. Arthur J. Whitman Roland F. Beers, ine. Brookhaven National Laboratory Dr. Robert A. Conard Sandia Corporation Mr. Hugh W. Church Dr. Thomas B. Cook,Jr. Mr. William Kingsley Mr. Jack W. Reed Los Alamos Scientific Laboratory Dr. Alvin C. Graves Dr. Herman Hoerlin Medical College of Virginia Dr. William T. Ham, Jr. U.S. Public Health Service Mr. John R. McBride Mr.Oliver R. Placak Mr. Morgan Seal Joint Task Force-8s Major Arthur L. Knipp, Jr. Mr. James M. Klaasse Mr. Lawrence B. Luhrs Mr. Sherwood B. Smith U.S. Weather Bureau Mr. Phillip W. Allen Mr. Mr. Mr. Dr. Frank D. Cluff Gilbert J. Ferber Robert J. List Lester L. Machta Mr. Kosta Telepadas 52 53