1. RASTA: The Radio Air Shower Test Array Enhancing the IceCube Observatory M. A. DuVernois University of Wisconsin IceCube Research Center for the RASTA & IceCube Collaborations

2. Geo-synchrotron extension to the IceTop component of the IceCube (deep in-ice + surface) experiment Built on the, now multiple, MHz RF cosmic ray experiments plus the existing IceCube Observatory at the South Pole In addition to CR measurements, extending the aperture of the surface array is significant as a CR veto to IceCube and lower-energy denser infill detectors at IceCube

3. RASTA Overall scheme & simulations

4. RASTA Overview Vision ~1000 antennas up to 3km from center  Usable up to 60° Radio emission from EAS Geosynchrotron: charged particles in the shower emit radio waves in earth magnetic field (10- 100MHz) Advantages suitable threshold: at a few PeV low per-channel & per-area cost easy and fast to deploy @ South Pole (at surface & with no freeze-in) Physics same as IceTop (cosmic rays) + enhanced zenith reach + sensitivity to X max + multi-detector events  control systematics

5. Simulations Radio signal simulation REAS3 [T.Huege et. al] CORSIKA based per-particle treatment agrees well with LOPES experimental data very slow (~8hrs/event) Fast simulation based on parametrization  under development Antenna simulation NEC 4 (LLNL package)  account for snow effects

6. Shower simulations Signal amplitude all electrons contribute to radio signal signal unattenuated in atmosphere  measures integral electromagnetic energy  good proxy for E prim Lateral signal distribution field strength amplitude vs. distance to shower axis  exponential function slope depends on depth of shower maximum X max  additional handle on composition

7. RASTA Plans for the array

8. R adio A ir- S hower T est A rray provide all prerequisites for a large scale array Multi-staged setup use existing infrastructure for first steps commercial central DAQ cabling networking develop new technologies in parallel buffered local DAQ self-triggering precision timing 100m

9. Timeline DAQ electronics development Analysis of second year data Analysis of first year data Fast simulation development effort First season: detect air-showers different antenna types dedicated transients study Ø(16) antennas  proof of viability Second season: demonstrate key technologies collect enough data for dummy analysis Ø(70) antennas  reliable sensitivity estimate Third season: refinement of trigger logic calibration with source In past year: Proposal for large array, data taking with ARA Description in arXiv:1010.1737

10. RASTA ARA (Askaryan Radio Array) TestBed

11. 2010 ARA TestBed South Pole R&D efforts test antenna designs determine noise level  symbiosis with ARA effort Current setup two antennas at ARA TestBed data since Jan 16 th, 2011 Continuous background galactic noise thermal self noise fold with antenna response  equivalent noise level: 5 μV/m 3.5 m

14. Therefore…the status… Proof of concept – In-ice antennas: “Death-Ray” fat `wire’ dipoles – Hardware deployment at Pole Proposal & Coordination – IceCube support – Proposal submitted for moderate scale array EMI & Analysis – Routine & flaring solar emission – Galactic noise (shown at ARA TestBed talk) New hardware to be installed with ARA1