1. RICE = “Radio Ice Cherenkov Experiment”
The Problem:
Mean free path of UHECR’s (E>1020 eV) limited by photoproduction on CMB: pgCMBDpp (“GZK”)
m.f.p. ~ 10 Mpc only sensitive to processes in last 30Myr!
At lower energies ( eV), reactions such as pgCMBpe+e-
Similar limitations for gamma-ray astronomy (pair production on CMB)
A solution (kinda): neutrino astronomy!
However, low fluxes at ZeV (1/km2/century) necessitate neutrino targets of scale km3
“Conventional” technology: PMT’s (AMANDA, Baikal, Antares, IceCube, Nestor, NEMO, SuperK) limited by absorption/scattering length of PMT photons (~40 m)
Radio attenuation length in-ice2 km (DATA!); acoustic attenuation length estimated at 10 km!! (SPATS measurements this year)
measure radio-wavelength rather than optical-wavelength portion of Cherenkov radiation: “Radio Ice Cerenkov Experiment”

2. Radio Detection of High Energy Neutrinos
Neutrino enters ice
Neutrino collision
Receivers (Rx)
Cones are +/- 3dB

3. RICE-AMANDA-SPASE (South Pole)

4. 17 in-ice half-wave ‘fat’ dipole antennas (400 MHz)

5. Effective Volume
Systematics:
Signal Strength
Transfer Function
Re(epsilon) (=n)
Im(epsilon) (=Latt)
Birefringence
System Total Gain
Livetime
Software Cuts

6. Diffuse Neutrino Search (1999-2005)
Phys.Rev. D73 (2006)

7. GZK nu models
No UHE neutrinos yet observed compare with theoretical predictions for how many neutrinos RICE should have observed, given sensitivity of experiment and radio transmission properties of ice
Two representative models: ESS/WB. Both bootstrap from observed charged CR spectrum and estimate neutrino flux (WB assumes all UHECR’s from GRB’s)
Diffuse GRB flux

8. Caution on presentation
RICE uses a 95% CL upper limit convention
(vs. conventional 90% CL upper limit convention)
ESS GZK-flux depends on several parameters
RICE upper limits based on most conservative (I.e., lowest flux – not typical)
Upper limits as a function of energy are largely for presentation only – sans energy resolution, only integral matters!

9. Volumosity? Voluminosity? Your model x our exposure

10. During RICE livetime, approximately 120 GRB’s in southern hemisphere w/ `nearly’ complete info. Only 5 with redshift information:
Astro-ph/ (accepted Astropart. Phys.)

11. RICE acceptance favors neutrinos incident along horizon at near-glancing angles

12. From photon flux to neutrino flux
Assume photon flux from p0 decay; relate photon flux to neutrino flux (from p+ decay) via Waxman-Bahcall.
Note: Limits generally weak (preferentially high-redshift sample)

13. South Polar ice is unique!
The future VISION
South Polar ice is unique!
Optical clarityIceCube (TeV threshold)
Radio clarityRICE (10 PeV threshold)
Purest water on planet & high hydrostatic pressureno impurities or defects in ice latticeclear propagation of acoustic wavesacoustic detection of sound wave produced by neutrino interactions! (EeV threshold)
South Pole is only place that can support all three neutrino detection technologies
: During bulk of IceCube hole drilling, co-deploy radio & acoustic modules into IceCube holes
1 km deployment scale x10 over current RICE
>2010: Dedicated hole-drilling (much cheaper holes!) for acoustic&radio over 10 km deployment scale

14. GZK detections / hybrid dector (c. 2010)

15. 06-07: codeploy with IceCube in 3-4 holes.
AURA
The Askaryan UnderIce Radio Array = THE BRIGHT, SHINING FUTURE!
Develop technology for larger radio array
Further map out the radio properties of South Pole Ice
Build intermediate detector with improved effective volume over RICE
06-07: codeploy with IceCube in 3-4 holes. KU

16. Co-deployment with IceCube: one scenario
spare attachment points on IceCube cable (1450m, 2450m, center of the string, an additional breakout could be added a 1400m for minimal cost) could accommodate a “DRM”
additional connectors added to pressure sphere would connect each of four antennas to form a cluster
grouping antennas in clusters at 10m separation, gives enough timing difference to distinguish backgrounds, thereby allowing a drop in thresholds
antenna calibration unit provided calibration and ice property studies
signal conditioning and amplification happen at the front end, signal is digitized and triggers formed in DRM
2450 breakout is for the dustlogger

17. Other deployment options
Separate cable taped to IceCube cable would allow deployment at shallow depths where rf tranparency is highest
Same paradigm as deployment--shown to work

18. In ice digitization done via the ROBUST board which will house the LABRADOR chip used by ANITA. The power consumption of the LABORADOR chip is xxx, and it requires hits in each of four bands.
Multibanded trigger requires signal in more than one band for triggering.

19. Relativistic magnetic monopole generates photon swarm.
Search for highly ionizing magnetic monopoles in Antarctic ice (Daniel Hogan, KU UG)
Relativistic magnetic monopole generates photon swarm.
Weizsäcker-Williams energy spectrum:
Jackson, 1963, etc.

20. Energy Loss in Earth: ionization+brem+pair production+ photonuclear
Check total energy loss against mmc package (dima chirkin) and also seckel, weiler&wick calculation
Razzaque et al., 2002

21. θ r l r Energy Loss in Earth Chord Length through Earth:
Loses energy as z=1/(2α) electric charge θ r l r

22. Preliminary monopole flux limits (+/- x2)