The ExaVolt Antenna Mission Concept and Technology Developments

Abstract

In the past decade, searches for the cosmogenic neutrino flux produced by the interactions of ultra-high energy cosmic rays with the cosmic microwave background have not yet resulted in detection. Radio detection of ultra-high energy neutrinos provides a cost-effective means probing large amounts of effective volume. The Antarctic Impulsive Transient Antenna (ANITA) balloonborne experiment, with sensitivity to neutrinos with energies >10 19 eV, has provided some of the most stringent limits on cosmogenic neutrino production models by searching for coherent radio Cherenkov signals produced by the Askaryan effect in Antarctic ice. The ExaVolt Antenna (EVA) is a mission concept to extend the sensitivity of balloon-borne radio neutrino detection to energies 10 17 eV. EVA uses a novel antenna design that exploits the surface area of the balloon to provide a reflector antenna with 30 dBi gain (compared to 10 dBi on ANITA). We will present an overview of the mission concept and recent technology developments. * Speaker.

Neutrino Astronomy

“…The final landing place was approximately 100 nm from Davis Station (AU), on the ice sheet and at an elevation of approximately 2500 m. Figure 13 shows a map of the trajectory. A new balloon antenna design for the Exavolt Antenna (EVA) project is in the prototype development phase [39]. EVA aims to implement a 30-dBi-gain antenna, exploiting the surface of a super-pressure balloon (SPB) to improve sensitivity to neutrino-induced radio-impulsive transients by a factor of 100 over that of ANITA.…”

Radio Detection of High Energy Neutrinos

“…61 In September of 2014, the EVA team carried out a test of a prototype instrumented SPB in a hangar at NASA's Wallops Test Facility to demonstrate that a feed array could be deployed inside of a SPB, and that the balloon could be instrumented with an RF reflector-receiver system that could be well understood by modeling. 62 The 1:20 scale prototype was a 5.7 m SPB balloon. Reflector tape was attached to the balloon near its equator and a feed array membrane held the receivers (dual-polarized sinuous patch antennas) and associated electronics over a section of its circumference for the test (see Figure 4).…”

“…We show projected limits for ARA37, EVA and SKA Phase 1 with the low frequency antennas. 62,64,80 In light gray we also show the current most competitive limits that were shown in Experiments are also working to increase their effective area in order to move their sensitivities down in Figure 7. Ground-based projects ARA and ARIANNA are working to expand their detectors, adding as many stations as funding and logistics allow.…”

“…: The sensitivity reach of future radio neutrino experiments at ultra-high energies and above. We show projected limits for ARA37, EVA and SKA Phase 1 with the low frequency antennas 62,64,80. In light gray we also show the current most competitive limits that were shown inFigure 1 for comparison.…”

“…: Pictures of the EVA prototype test (balloon, toroidal reflector, and dualpolarized sinuous feed antennas) at NASA's Wallops Test Facility 62. Photo credit to Peter Gorham.5.…”