THROUGH HIGH ENERGY NEUTRINO ASTROPHYSICS WE EXPLORE THE STRUCTURE AND EVOLUTION OF THE UNIVERSE IN A UNIQUE WAY AND LEARN ABOUT THE PHYSICS INSIDE OF ASTROPHYSICAL SOURCES THAT DRIVES THE ACCELERATION OF THE HIGHEST ENERGY PARTICLES. BALLOON-BORNE AND GROUNDBASED EXPERIMENTS ARE POISED TO DISCOVER THESE ULTRA-HIGH ENERGY (UHE) COSMOGENIC NEUTRINOS BY LOOKING FOR RADIO EMISSION FROM TWO DIFFERENT TYPES OF NEUTRINO INTERACTIONS: PARTICLE CASCADES INDUCED BY NEUTRINOS IN GLACIAL ICE AND EXTENSIVE AIR SHOWERS IN THE ATMOSPHERE INDUCED BY THE CHARGED-PARTICLE BY-PRODUCT OF TAU NEUTRINOS INTERACTING IN THE EARTH. THESE IMPULSIVE RADIO DETECTORS ARE ALSO SENSITIVE TO RADIO EMISSION FROM EXTENSIVE AIR SHOWERS INDUCED DIRECTLY BY UHE COSMIC RAYS. BALLOON-BORNE EXPERIMENTS ARE ESPECIALLY WELL-SUITED FOR DISCOVERING THE HIGHEST ENERGY NEUTRINOS AND ARE THE ONLY WAY TO PROBE THE HIGH ENERGY CUTOFF OF THE SOURCES THEMSELVES TO REVEAL THE ASTROPHYSICS THAT DRIVES THE CENTRAL ENGINES INSIDE THE MOST ENERGETIC ACCELERATORS IN THE UNIVERSE. BALLOON PLATFORMS OFFER THE CHANCE TO MONITOR EXTREMELY LARGE VOLUMES OF ICE AND ATMOSPHERE. THE ANTARCTIC IMPULSIVE TRANSIENT ANTENNA (ANITA) AND THE EXAVOLT ANTENNA CONCEPT BOTH LEVERAGE THIS PLATFORM AND ARE OPTIMIZED FOR DISCOVERY OF THE HIGHEST ENERGY NEUTRINOS. WE ARE DEVELOPING AN INTERFEROMETRIC PHASED ARRAY TRIGGER FOR THESE IMPULSIVE RADIO DETECTORS A NEW TYPE OF TRIGGER THAT WILL IMPROVE SENSITIVITY SUBSTANTIALLY AND EXPEDITE THE DISCOVERY OF THE HIGHEST ENERGY PARTICLES IN OUR UNIVERSE. WE HAVE DEVELOPED AN 8-CHANNEL INTERFEROMETRIC TRIGGER BOARD FOR GROUND-BASED APPLICATIONS THAT WAS DEPLOYED IN DECEMBER 2017 WITH THE GROUND-BASED ASKARYAN RADIO ARRAY (ARA) EXPERIMENT AT THE SOUTH POLE AND IS CURRENTLY WORKING AS DESIGNED. PRELIMINARY MONTE CARLO SIMULATIONS INDICATE THAT THE COSMOGENIC NEUTRINO EVENT RATE WILL GO UP BY A FACTOR OF ~3 WITH THE NEW TRIGGER. THE TRUE POWER OF THE INTERFEROMETRIC TRIGGER IS IN SCALING TO LARGE NUMBERS OF CHANNELS AND THE DISCOVERY SPACE THAT IS ONLY AVAILABLE FROM A BALLOON PLATFORM AT THE HIGHEST ENERGIES IS EXTREMELY APPEALING. UNDER THE APRA FUNDED IN ASSOCIATION WITH THIS ROMAN TECHNOLOGY FELLOWSHIP (RTF) PROPOSAL WE WILL BUILD ON AND EXTEND THE NASA INVESTMENT IN THE ANITA LONG DURATION BALLOON (LDB) MISSION AND THE MANY OTHER COMPLEMENTARY PARTICLE ASTROPHYSICS LDB MISSIONS BY DEVELOPING THE ELECTRONICS REQUIRED TO BRING A LARGE-SCALE RADIO INTERFEROMETRIC TRIGGER TO A BALLOON PLATFORM EXTENDING THE SCIENTIFIC REACH OF ANY FUTURE LDB OR SUPER PRESSURE BALLOON (SPB) MISSION FOR RADIO DETECTION OF THE HIGHEST ENERGY COSMIC PARTICLES. WE WILL DEVELOP AN INTERFEROMETRIC TRIGGER SYSTEM THAT IS SCALABLE TO O(100) CHANNELS AND SUITABLE FOR USE ON A BALLOON PLATFORM. UNDER THIS PROPOSAL WHICH BUILDS ON THE FUNDED APRA THAT IS ASSOCIATED WITH THIS RTF REQUEST WE WILL POSITION THE VIEREGG GROUP AT UCHICAGO TO BE A LEADER IN THE DEVELOPMENT OF FAST RADIO DETECTORS DESIGNED FOR DISCOVERING UHE COSMIC PARTICLES WITH AN EYE TOWARD BECOMING THE PI OF A BALLOON MISSION IN THE NEXT 3 YEARS. WE WILL: 1) PURCHASE A FREEZER LARGE ENOUGH TO TEST THE PHASED ARRAY INSTRUMENTATION THAT WE ARE BUILDING FOR BALLOON-BORNE AND GROUND-BASED APPLICATIONS AND PURCHASE TEST EQUIPMENT REQUIRED TO DEVELOP RADIO FREQUENCY ELECTRONICS. 2) DESIGN ANTENNAS AND A FRONT-END AMPLIFICATION AND FILTERING SYSTEM THAT WILL BE REQUIRED TO TURN THE O(100) CHANNEL TRIGGER AND DATA ACQUISITION ELECTRONICS THAT ARE FUNDED UNDER THE ASSOCIATED APRA AWARD INTO A FULL BALLOON CONCEPT AND PROPOSAL. 3) CONTINUE TO DEVELOP MONTE CARLO SIMULATIONS TO DETERMINE THE OPTIMAL EXPERIMENTAL CONFIGURATION THAT LEVERAGES THE NEW PHASED ARRAY TECHNOLOGY.