8. TECHNICAL FACILITIES ‘43D 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 inrediately 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 measurements 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 represerited in almost every test, the technical facilities at NTS -- and particularly those which are used again and egain ~~ rast be flexible, 1 oz qyosmres Air drop targets are a surfaced cres $s, with concentric circles marked, and lighted for pre-dawr, sncts. They a:¢ surrounded by structures and instruments much as those d escirltes below, Test towers are of various neights and strenmths, depending upon the conditions of the test. They have in the past most frequently been of 300 and 500 fect, although lower towers have been used, The strength is varied according to the weight and size of equipment the tower will suppert. 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. con 7 OE * LAR