we 8, TECHNICAL FACILITIES #D INSTRUMENTATION Purpose of Technical Facilities . \ The scientific objective in nuclear tests is to make objective and quantitative measurements of the physical phenomena involved so as to compare them with previous performance, to verify theoretical predictions, and to understand more fully the phenomena involved, Generally the various measurements are divided into two categories, those in which quantities intrinsic to the device itself are measured, and those in which the effects of the device upon its environment are determined. The diagnostic measurements are imreediately related to the problems of weapon development, The list of quantities or effects which may be measured for diagnostic purposes may include gamma rays, neutrons, visible light, and thermal or other electromagnetic radiation. Effects measurernents may include blast pressures, wind losdings, thermal effects as on materials, radioactivity, visible light and gamma rays as in their effect on animals. Technical Structures and Instruments In view of the varied interests represented in almost every test, the technical facilities at NTS -- and particularly those which are used again and again -- riast de flexible. Air drop targets are a surfaced cress, with concentric circles marked, and lighted for pre-daw. sicts. They are surrounded by structures and instruments much ay those desciites below. Test towers are of various neights and strem,ths, depending upon the conditions of the test, They have in the past most frequently been of 300 and 500 fest, altnough lower towers have been used.The strength is varied according to the weight and size of equipment the tower will support. They are designed to use as little material as possible, partly for economy but primarily to reduce the quantity, of vaporized material which will contribute to the radioactive cloud and fallout. Unvapcrized pieces of towers on some shots have been thrown for considerable distances and constitute a hazard affecting the placement of maneuver personnel. cert D0 * _ 32 ~ LAL. "