1. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Radio Detection of Astrophysical Neutrinos David Seckel University of Delaware

2. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Cosmic Neutrinos Big Bang< 1 eVThermal Solar.1 – 10 MeVThermonuclear Supernovae5 – 50 MeVThermal Atmospheric100 MeV – 100 TeV Hadronic (  -decay) Cosmic-ray sources1 TeV – 10 EeV Hadronic Cosmic-ray propagation100 PeV – 10 EeVP-  reactions (GZK)

3. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Cosmic Rays Nuclear (P, Fe?) –~ E -3 spectrum to 10 19 eV –Sources not observed directly –GZK process should absorb but… Gamma rays –~ E -2  ’s observed to 10 12 eV –Nearby sources only Suggests –E -2 source spectrum –p,n interact in source –Predicted fluxes

4. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Cosmic Ray Neutrinos  production  decay Location –Atmosphere –Source –Propagation Flavor –No mixing –Full mixing If  then Comments

5. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Expected Fluxes P P+X P+  source GZK Waxman - Bahcall –Known intensity –E -2 –Thin (1 per p) But… –Not thin ? –Didn’t include GZK Perhaps WB is better as a lower bound…Anyway - it sets the scale…

6. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 High energy cross-sections  ~ E, E < M W 2 /m p Continued increase due to growth of parton distribution in p,n The Earth becomes opaque at high energy. * Perhaps non-standard cross-sections – extra dimensions, black holes, etc.

7. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Detector Scale Atmospheric 1-100 GeV Astro-Sources 0.1 TeV - 10 PeV GZK 0.1-10 EeV

8. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Summary of motivation SourceStatusEnergyDetector Scale TechnologyExamples AtmosphericObserved1-10 4 GeV(40 m) 3 Water Optical Cerenkov Super-K Astrophysical Sources Plausible (but uncertain) 1 PeV1 km 3 Water Optical Cerenkov IceCube Antares/Nemo GZK +“guaranteed”0.1-10 EeV1000 km 3 Radio Cerenkov RICE/ANITA SALSA/GLUE And lots of more exotic sources, cross-sections, new physics, …

9. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Radio Detection of Showers Askaryan: Coherent radiation S ~  Q ~ 0.25 E s /GeV ~ R M ~ 10 cm  /l ~ 3 deg Confirmed by –SLAC T444, Saltzberg et al. PRL 2001 –SLAC T460, Gorham et al. 2002

10. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Scaling behavior fractional excess  V  t l max Single particle signal Includes LPM effect

11. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 RF spectrum Field calculation is integral over shower profile Separation of shower profile Separation of form factors With scaled frequencies Adapted from Alvarez, Vazquez, Zas “Full sim” is approx a Blue – Gaussian for f(z), AVZ approx c for G y Red – Griessen for f(z) Separation of phase factors

12. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 LPM effect & Hadronic showers LPM lengthens shower –Narrows cherenkov cone E < 1 EeV e CC showers y =.8 E > 1 EeV hadronic-showers – y =.2 –3 flavors * (CC + NC) = 4.5 channels –No LPM - no  0 decay above a few PeV (coincidence).

13. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Radio Propagation in Ice Rx fixed Tx lowered into “dry” hole t 0 (z) gives index of refraction 2nd pulse is reflection

14. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Radio Attenuation in Ice Solid – Provorov (used by RICE) Dashed – Matsuoka + Westphal Curves offset for visibility RICE bandpass High frequency – pretty consistent Low frequency – big variations with ice sample – proton mobility Plans to measure at pole, 2003-04

15. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 R adio I ce C herenkov E xperiment PI

16. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 RF Detection (RICE version) 5 km RF technique –Event –Shower: EM and/or hadronic –RF pulse –Propagation –Antenna –DAQ

17. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 16 Rx (10 cm dipole) 5 Tx 3 Horns 4 Oscilliscopes (x4) DAQ PCs Pulse Generator Dry hole Pole: Network analyzer Antenna range Kansas: RICE Deployment

18. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Channel and DAQ configuration Power Scope Trigger generator Antenna Amp in PV cable AmpFilter Splitter PC 4 hits within 1200 ns Latch scope TDC times to PC On-line veto (TDC times) Read scope Write to disk 8  sec 1 ns sample 500 MHz

19. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Single Channel Calibrations 200-500 MHz: +/- 3 dB (E) TX….RX antenna + amplifier calibrations cable (TX, RX) and filter relative geometry of TX/RX (r, q)

20. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Pulse shape simulation Disc. threshold Background taken from data sample

21. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Limited by attenuation 60,000 e - showers at E = 1 EeV Black dots – sample Red dots – events which would trigger RICE ~ 5% efficiency Limited by Cherenkov angle Monte Carlo

22. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 RICE effective volume for e -,  showers Range due to varying signal strength by 0.5-2 Range due to varying attenuation by 0.5-2 Multiply by 2  sr This is appropriate for e charged current events.

23. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 LPM and hadronic showers With LPM Without LPM “Hadronic” E s = 20% E

24. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 RICE I: Data Analysis 333.3 hrs livetime TDC times Waveform data {

25. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 No Events! (yet) ICRC 2003 SPIE 2002 Astro-ph 2002 AstroPart Phys. 2003

26. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Potential Systematic Effects (see astro-ph/0206371 )

27. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 ANITA Peter Gorham

28. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Antarctic Impulsive Transient Antenna (ANITA) ANITA Goal: Pathfinding mission for balloone-borne neutrino telescope NASA SR&T start 2003, LDB launch in `06-`07 austral summer season Requires early measurements of Antarctic EMI at float altitudes  determines instrument final design M. Rosen, Univ. of Hawaii ANITA Gondola & Payload Antenna array Crush pad/struts not shown Solar Panels Mean ice depth ~1.2km SIP & SIP PV array

29. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Critical Developments Broad band antennas with 30 deg field of view, two polarizations Survey of EMI backgrounds – ANITA Lite Low power multichannel digitizer –>= 1GHz analog input bandwidth (200-1200MHz) –multi-GSa/s sampling rate (Nyquist limit ideal) –minimum phase distortion for clean polarization –dynamic range (>= 10 bits) –internal Analog to Digital Conversion (ADC) –short record length (100-200ns if optimally matched) –self-triggering with fine threshold adjustment –bi-polar triggering –deadtimeless  conclude multi-hit buffering needed

30. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 STRAW2 Chip 16 Channels of 256 deep SCA buckets Self-Triggered Recorder Analog Waveform (STRAW) Optimized for RF input Microstrip 50  Record length: 128-256ns Self-Triggering: Target input Bandwidth: >700MHz -LL and HL (adj.) for each channel Sampling Rate: 1-2GSa/s (adj.) -Multiplicity trigger for LL hits On-chip ADC: 12-bit, >2MSPS External option: MUXed Analog out Sampling Rates >~8GSa/s possible w/ 0.25  m process 8192 analog storage cells Die:~2.5mm 2 (From Gary Varner, UH)

31. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 ANITA MC Ec = 3e18 eV 5.6 deg upcoming 100m depth Ec = 2.5e18 eV, 0.7 deg upcoming depth 950m ~30 deg ~45 deg Method: monte carlo ray bundles from ZHS distribution, then ray-trace through the ice+firn to surface, then use fresnel equations Also extending RICE Monte Carlo Issue: Roughness of Air-Ice interface

32. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Current best sensitivity estimates From: Peter Gorham

33. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Anita-lite Configuration (w/TIGER) 2 quad-ridged horn antennas on SIP level Electronics 1atm case (also SIP level) PV array addition Telemetry integrated w/ TIGER  marriage made in heaven (Lady & the tiger) Anita-lite PV array: Probably integrated in single tier

34. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 ANITA-lite as-built Configuration Antenna arrangement Instrument housing under TIGER Redundant fast-recovery USB harddrive (8GB) Housing, hard drive, veto antenna Electronics integration into pressure housing

35. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Air Shower Detection Demonstration that Radio Cerenkov works “in the wild” Detector Calibration Cosmic ray composition ?

36. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Impact of shower core

37. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 RF pulse: r ant = (0,0,-150m), d sh = +x on cone Arrival time distribution RF Pulse at antenna Combined spectra w/phases Individual spectra above 300 GeV

38. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Different pulse shapes for different observers

39. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Compare strength of air/ice shower signals Need to correct for constant n = 1.78 –Narrower C-cone –Increases E –No focusing Vertical shower –Slant will evolve shower Higher E more efficient –Will penetrate (less evolved) Proton vs Fe –Fe more evolved - larger  H

40. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Plausible event rates A = 1 km 2 Impact Rates –E s > 1 PeV = 10 8 /yr –E s > 1 EeV = 10 2 /yr Threshold –E (in ice) ~ 300 PeV (RICE) –E (in ice) ~ 10 PeV (Optimized ?) Need MC of air shower rates, array design –Toy calc with RICE 10 EeV air shower, r = 2 km,  z < 45 0.1 EeV ice shower, z = 1 m (w/LPM) No ray tracing (change geometry/strength)  eff   ) = 1.9 km 2 sr

41. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Composition with radio ? Proton gammaFe Average of 50 x 1 PeV showers

42. David Seckel, Radio Detection of Astrophysical Neutrinos, Karlsruhe, Oct. 14, 2003 Summary Cosmic Rays & Neutrinos linked Other cosmic neutrinos/particle physics not discusse RF detection offers large effective volumes RICE maturing as a prototype ANITA discovery potential designed for GZK Air shower detection w/composition ?