STONES: Stockert Neutrino Search at 1.4 GHz

1. STONES: Stockert Neutrino Search at 1.4 GHz Peter M.W. Kalberla Argelander-Institut für Astronomie Bonn Jürgen Starek Förderverein Astropeiler Stockert e.V.

2. Lunar Cherenkov emission neutrino photon shower Courtesy Ron Ekers ATNF

3. Radiotelescopes as detectors • Askaryan effect causes microwave emission • Use 2·1014 g lunar regolith as target • Coherent broadband continuum pulse • Peak emission at ~2 GHz • Δt = 0.5·10-12 s (observations bandwidth limited, Δt~5 10-9s) • 100% linear polarization • Ionospheric dispersion ~10·10-9 s • Distinguish terrestrial or interstellar signal • Faraday rotation also useful

4. However: • Radio telescopes are expensive devices • Time allocation committees need to consider a broad range of different scientific fields • Radio telescopes are oversubscribed • UHE neutrino flux is low – observations need huge amounts of time • Way out: Use a dedicated telescope

5. We have such a telescope ! 25 m diameter Astropeiler Stockert built 1956 operated by University of Bonn and MPIfR shut down 1997 became private property industrial monument 1999 since 2005 owned by NRW foundation Reconstruction completed back to operation soon

6. Stockert - technical details • New prime focus system at 1.4 GHz, Tsys= 30 K • Bandwidth 140-300 MHz • HPBW 0.6 deg • 3 GHz FPGA transient recorder • Second receiver at 700 MHz for simultaneous observations at two frequencies?

7. Skimming the Moon with HPBW 0.6O 25-m dish most sensitive at 1.4 GHz

8. Technical details – 1956 and today

9. Observing UHE neutrinos – one week

10. Observing UHE neutrinos – one week in l,b

11. Sky coverage in equatorial coordinates

12. Sky coverage in Galactic coordinates

13. Sensitivity - 1 year limits (thanks to C.W. James) Limits can be improved!

14. Feasibility tests with Effelsberg

15. Radar and broad band emission

16. Conclusions • A long term project with a 25 m telescope can explore a new parameter space • After completion of the reconstruction work only little additional effort necessary for such a project • automated telescope control • second receiver at 700 MHz for coincidence tests • All together < 25 K€ • Low cost experiment (operations < 300 K€ for 3 years)

17. Problems to solve • The NRW foundation does not support scientific projects • FAS short in manpower and budget • Automated telescope control necessary • The Deutsche Forschungsgemeinschaft (DFG) supports scientific projects but no operational costs • We need to find a sponsor who would be willing to pay for electricity and telescope maintenance….

18. Catch the neutrino www.astropeiler.de