THE GIANT RADIO ARRAY FOR NEUTRINO DETECTION THE

THE GIANT RADIO ARRAY FOR NEUTRINO DETECTION & THE GRANDProto 300 EXPERIMENT http: //grand. cnrs. fr/ Olivier Martineau-Huynh for the GRAND collaboration, October 12, 2018

WHY UHE NEUTRINOS? • • • «Cleanest probe» of the Universe (no deflection, no attenuation, hadronic…) E>1017 e. V neutrinos is uncharted territory Direct link to highest energy CRs (5%/A of primary energy)

t± • Detection principle: • n-induced tau decays in atmosphere generate ~horizontal extensive air showers [Fargion astro-ph/99066450] • Issues: • VERY seldom events giant detector • Earth-skimming trajectories (ln <~1000 km) Radio-detection

RADIO DETECTION OF VERY INCLINED SHOWERS 50 -200 MHz radio emission of a 1017. 5 e. V shower viewed from the side: ~10 s of km² detectable footprint @ ~100 km from decay point!! Elevation (km) Background level: 15µV/m Use mountains as projection screen for radio emission

The GRAND project • Size of ethe neutrino detector is a key ! k we t Ulastai ex parameter. n iv X r a n>10000 o • km²? t Ou - technical capacity? - topology? 5

GRAND NEUTRINO SENSITIVITY COMPUTATION • End-to-end custom simulation A- DANTON: n t decay backward MC over realistic topography. V. Niess and OMH, astro-ph/1810. 01978. A. Zilles et al. , in prep. B- Radio. Morphing: semi-analytical computation of the air-shower-induced Efield transient signal. A. Zilles et al. , ARENA 2016, astro-ph/1809. 04912

GRAND NEUTRINO SENSITIVITY SIMULATIONS • End-to-end custom simulation C- Antenna response: HORIZONANTENNA, h=5 m, f = 50 -200 MHz, optimized for very inclined trajectories. Response simulated in NEC 4. En = 2 1019 e. V; q = 93° Trigged antennas 10 000 km² Hot. Spot 1 Antenna gain (NEC 4) t decay n CC interaction D- Layout: 10’ 000 antennas with 1 km step square grid on area with favorable topography (Tian. Shan mountains, China). Trigger: Peak-peak voltage > 2 snoise (agressive) or 5 snoise (conservative) & cluster of 5 neighbouring antennas.

GRAND SCIENCE CASE • • • GRAND 10 k (10’ 000 km²) competitive with ARA-ARIANNA. Aiming at ~20 such subarrays deployed on areas with favorable topography at different locations in the world GRAND 200 k (20 x 10 000 km²) Sensitivity of full array good enough for GRAND to detect cosmogenic neutrinos for standard hypothesis 200 000 km² detection area makes GRAND a perfect tool for UHECR & UHE g ray physics. Also FRBs & Eo. R. See mini-workshop on Future for GRAND answers to key science questions

GRAND technical challenges 20 x 10 000 km² arrays of autonomous radio antennas to detect, identify and reconstruct very inclined air showers? . . . Seriously? Autonomous radio-detection of air showers is a technical issue, not a Physics one More @ mini workshop on Future. Staged approach GRAND pathfinder: GRANDProto 300 Experimental polarisation Simulated EAS CODALEMA, astro-ph/1710. 02487 Experimental candidates Simulated EAS TREND, astro-ph/1810. 03070 ARIANNA, astro-ph/1612. 04473

GRANDProto 300 Site: 8 sites surveyed in China, 6 with excellent electromagnetic conditions Horizon. Antenna, succesfully tested in the field (August 2018) Electronics: 50 -200 MHz analog filtering 500 MSPS sampling, FPGA+CPU Wi. Fi data transfert Prototype board going to prod. Layout: 300 antennas, 200 km², 1 km step size with denser infield Erange = 1016. 5 -1018 e. V

GRANDProto 300 GOALS GRAND pathfinder, but also a standalone, independent project. Targeted run period: 2020 -2025. • Autonomous proof-of-principle of autonmous radio-detection of air showers. Trigger, selection and reconstruction of very inclined CRs in 1016. 5 -1018 e. V. validation thru comparison of primary properties -spectrum, direction of arrival & composition- to known results. • Testbench for further GRAND stages: advanced methods for trigger+background rejection (Machine Learning, etc) and data collection. Power consumption optimization. Preliminary

GRANDProto 300 HYBRID ARRAY • GRANDProto 300 will be complemented by an independant, autonomous ground array with large acceptance to inclined showers. • Independant detection of electromagnetic & muon components on a shower-toshower basis unbiased measurements of E (≈Eelm), Xmaxµ and Nµ. elm muons

GRANDProto 300 PHYSICS PROGRAM • Great tool to study air shower physics in the 1016. 5 -1018 e. V energy range. z H. Dembinski, UHECR 18 • Insight on the Galactic. Extragalactic transition

CONCLUSION • GRAND will be a giant array of 20 x 10 000 radio antennas deployed at several locations in the world, to be completed in 203 x. Very rich science case centered on UHE cosmic particles. • Pathfinder: GRANDProto 300, to start in 2020. A standalone project! Exciting setup & science! • You think radio could/should be the technique of the future for UHE astroparticles? Join us and bring your ideas! • Post. Doc position opened @ Penn State (contacts: Miguel Mostafa miguel@psu. edu & Kohta Murase murase@psu. edu) • Want to know more/keep in touch? • Check out our webpage: http: //grand. cnrs. fr • Read our white paper «GRAND science & design» on ar. Xiv next week! • Subscribe to our info list GRAND-ALL-L@IN 2 P 3. FR (email to omartino@in 2 p 3. fr)

GRANDProto 35 • GRANDProto 35: bridge between TREND & GP 300. Now in commissioning. Stable DAQ operation over long periods 26 days Hybrid array with independant trigger 100% DAQ up-time