RASTA:The Radio Air Shower Test Array

Enhancing the IceCube Observatory

M. A. DuVernoisUniversity of Wisconsin

IceCube Research Centerfor the

RASTA & IceCube Collaborations

• 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

RASTAOverall scheme & simulations

RASTA OverviewVision

~1000 antennasup to 3km from centerÈ 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 Xmax + multi-detector eventsè control systematics

SimulationsRadio 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 parametrizationè under development

Antenna simulation NEC 4 (LLNL package)è account for snow effects

Shower simulations

Signal amplitude all electrons contribute

to radio signal signal unattenuated in

atmosphereè measures integral

electromagnetic energy è good proxy for Eprim

Lateral signal distribution field strength amplitude vs. distance

to shower axisè exponential function slope depends on

depth of shower maximum Xmax

è additional handle on composition

RASTAPlans for the array

Radio Air-Shower Test Array provide all prerequisites

for a large scale array

Multi-staged setup use existing infrastructure

for first steps commercial central DAQ cabling networking

develop new technologiesin parallel

buffered local DAQ self-triggering precision timing

IceTopstation

radioantennas

trench

magneticnorth

networkhub

FCUcable

SJB

to ICL

100m

Timeline

DAQ electronics developm

ent

Analysis of second year data

Analysis of first year data

Fast simulation developm

ent effort

First season: detect air-showers different antenna types dedicated transients study Ø(16) antennas

è proof of viability

Second season: demonstrate key technologies collect enough data for dummy analysis

Ø(70) antennasè 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

RASTAARA (Askaryan Radio Array) TestBed

2010 ARA TestBedSouth Pole R&D efforts

test antenna designs determine noise levelè symbiosis with

ARA effort

Current setup two antennas

at ARA TestBed data since

Jan 16th, 2011

Continuous background galactic noise thermal self noise fold with antenna responseè equivalent noise level: 5 μV/m

3.5m

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