A PROPOSAL TO INVESTIGATE PHYSICAL LIMITING MECHANISMS IN NUCLEAR EXPLOSION INDUCED LIGHTNING (NEIL)

NUCLEAR EXPLOSION INDUCED LIGHTNING (NEIL) REPRESENTS A POTENTIALLY SEVERE THREAT TO MILITARY SYSTEMS REQUIRED TO SURVIVE AND FUNCTION AFTER EXPOSURE IN THE SOURCE REGION OF A NUCLEAR EXPLOSION. WHEREAS THERE EXISTS SOME UNCERTAINTY ABOUT THE NATURE AND MAGNITUDE OF THE THREAT, ITS EXISTENCE IS CONCLUSIVELY DOCUMENTED IN THE FILM RECORD OF ATMOSPHERIC NUCLEAR TESTS IN THE PACIFIC DURING THE 1950'S. SINCE NO HARDENING STANDARD IS IN PLACE FOR IT, NEIL REPRESENTS AN AREA OF UNKNOWN VULNERABILITY FOR CRITICAL SYSTEMS WHICH WOULD OTHERWISE BE HARD TO NUCLEAR WEAPONS EFFECTS. THE DIFFICULTY WITH ESTABLISHING A USEFUL STANDARD CENTERS ABOUT THE IMMATURE STATE OF THE MODELS DESCRIBING THE EFFECT AND THE LACK OF CONVINCING EXPERIMENTAL CONFIRMATION. THE OBJECTIVE OF THE PROPOSED WORK IS TO DETERMINE THE MAXIMUM MAGNITUDE AND DURATION OF CURRENTS EXPECTED TO FLOW IN A NUCLEAR LIGHTNING EVENT. THIS GOAL WILL BE ADDRESSED THROUGH THE DEVELOPMENT OF NUMERICAL AS WELL AS ANALYTICAL MHD PLASMA MODELS OF NEIL WITH PARTICULAR EMPHASIS ON THE EFFECTS OF INSTABILITIES AND OTHER PHENOMENA THAT AFFECT CHANNEL CURRENT.