CHAPTER IV TASK GROUP 7,4 AND THE SHOT SERIES* Originally, Joint Task Force SEVEN had three primary scientific objJectives in CASTLE: to fire seven experimental devices, six of which were in the megaton range, and three of which were to be proof tests of emergency capability weapons; to obtain diagnostic information on these devices necessary to evaluate properly their performance in case of suc- cess or failure; and to obtain effects information on megaton devices. The intention was to fire five devices developed by LASL and two devices ; developed by the University of California Radiation Laboratory at Livermore, —_ 3