Order number 940406-165953-13 -001-001 page 19 set 5 wi th 341 of 341 items NITROGEN/fluorescence ;AIR/fluorescence ; ATMOSPHERE/fluorescence ;ATMOSPHERIC BURSTS/teller light ;OXYGEN/fluorescence ;SEA LEVEL; STREAK PHOTOGRAPHY; FLUORESCENCE; AIR; ATMOSPHERE; COMPUTERIZED SIMULATION; NEUTRONS; GAMMA RADIATION; OXYGEN Item 32 150. 110. REPORT NUMBER PRIMARY TITLE (M) LA--10680-MS-Vol.1 Status of high-altitude fireball simulations and implications for test detection and diagnostics. Volume I. PERSONAL AUTHOR( M) CORPORATE SOURCE Simulation status (U) Sappenfield, D.S. Los Alamos National Lab., NM (USA) 750. PUBL. ANNOUNCEMENT -032719 371. PUB. DATE (YYMMDD ) 860300 34. CLASSIF. LEVEL T EXT Secret 950. ABSTRACT Ability to simulate numerically the early phases of high-altitude nuclear explosions is necessary to provide input to nuclear burst detection systems, to provide algorithms that relate observables-to-explosion parameters, and to provide initial conditions for Simulations of long-time-scale nuclear effects that may interfere with performance of military systems. This report surveys the status of our simulation capability for explosions between 10- and 100-km altitude, with emphasis on optical observables and radiated energy loss. Computed optical signals are compared with 70. 710. observations of the Bluegill, Kingfish, Checkmate, Tightrope, Yucca, Orange, and Teak nuclear tests. The comparisons are generally very good. The weakest aspects of the simulations are in the areas of weapon debris contribution to optical emission and substructure of the first optical pulse from Tightrope and Yucca. The low-altitude limit to the time integral of power, weighted for silicon sensor response, is re-examined. From data obtained during Operation Dominic, it is concluded that the most likely value is 0.13 of the total yield, although an argument can be made for a value of 0.15 times the yield. The possibility of non-local-thermodynamic~-equilibrium (non-LTE) effects on Simulation of the Bluegill event is discussed. Using currently accepted chemical rate constants and energy. Partitions, one cannot make a convincing case for Significant non-LTE effects. Nevertheless, some aspects of the Bluegill simulation are improved by non-LTE treatment of NO density and N/sub 2/ vibration 801. KEYWORD(S) 9003210 excitation. (U) BALL OF FIRE/computerized simulation ;ATMOSPHERIC BURSTS/ball of fire ;ATMOSPHERIC BURSTS/optical