july 10, 2007 detection of askaryan radio pulses produced by cores of air showers. suruj seunarine,...

July 10, 2007

Detection of Askaryan radio pulses produced by cores of air showers.

Suruj Seunarine, Amir Javaid, David Seckel, Philip Wahrlich, John Clem

D. Seckel, Univ. of Delaware

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Topics

• Concept: – A source to test radio techniques– CR composition ?

• Askaryan pulses & air shower dimensions

• Air shower properties (AIRES & CORSIKA)– Particle content– Radial and energy distributions

• Calculation of RF signal– Coherent addition of subshowers– Issues: near zone/far zone, ray tracing

• Composition studies

• Detection– IceCube: shallow array, AURA– ANITA

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Theorist’s view of the UHE neutrino sky

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Recall how radio works

5 m

10 cm

JC, SY: “How do you know when you haven’t seen anything?”

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Radio Goals & Staging

• 100 events/yr above 1018 eV

• >1000 km3 sr

• Validation of design for field work

• Prototype projects – more than upper limits

• Detect Air Showers: Signal/Background/Calib

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Askaryan pulses from air shower core

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Critical dimensions

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

High energy ground level particles at SP

• CORSIKA/AIRES– Primary energy: 1,10,100,1000 PeV– Cutoff: 1,10,100,1000 GeV– Composition p & Fe

• Explore– Particle content rad - meson - baryon - mu

– Radial profiles Esh vs r

– Shower development dN/dE, ancestry

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Ground level particles

e-

n,p

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Radial distributions by particle ID

radiatingmesonsbaryonsmuons

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

E vs r (AIRES)

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

E vs r (CORSIKA)

Fraction of available energy approaches 10% by 100 PeV

Scaling allows use of high cutoff

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Synthesis of Askaryan pulses

• Many ground level particles– Superposition

• Individual RF pulses– Event: (id, te, xe, n, E)

– SubShower: (ts, xs, n, (r,l,s))

– Resolve geometry to antenna– Launch EM pulse (scaled AVZ)– Propagation effects (1/r, attenuation)– Adjust phase to common time basis

• Response– CoAdd spectra (t, n, pol, (complex spectrum))– Antenna/DAQ

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Subshowers & Coherence of RF pulses

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Time Domain Waveforms

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

RF: (Ep = 1 EeV, Ecut = 1 TeV )

20 10 0 10 20600

400

200

0

200

400

t nsm

V

Simulat ed p ulse in a R ice ant enna ch 6

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

EeV/TeV again

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

RF Cerenkov Rings

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

RF vs Core Size

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Determining Cosmic Ray Composition

• AIRES showers (from S. Seunarine)

• Esh(r<20 cm) as proxy for radio

• High-lite: 10 PeV, True iron

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Comparison of Fe/p

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Scaling & Rates

• Rate independent of D• Threshold increases with D• True for E-3

– But not for E-2

• Rate for 30m*30m @ 3PeV = 1/hour

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Shallow Array Concepts

• Drill 16 x 30m holes – 1 dom per hole– 4 antennas per dom

• 2 x 50m cables to each of four nearby strings & SJB• 2 doms per cable

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

AURA geometry

255 0 260 0 265 0 270 0

0 .0

0 .5

1 .0

1 .5

2 .0

2 .5

3 .0

3 .5

t ns after impact V

offset

Simulat ed R IC E resp onse w A U R A t iming

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

ANITA (A. Javaid)

• Rate– A 1.5 106 km2 sr– 1400/day E>1019 – ? /day E>1020

• High, Thin, Ice

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Summary

• Test beam for radio sure would be nice

• Air Shower Cores: Eeff ~ 10% Ep (at EeV)

• Synthetic RF looks usable• CR Composition Measurement

– Core energy anti-correlated with deep- – p-Fe separation

• Three scenarios– Small subsurface array w/IceTop– AURA– ANITA

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

END

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Radial distributions by energy

-1.5 -1 -0.5 0 0.5 1 1.5 2xm

-1.5

-1

-0.5

0

0.5

1

1.5

2

ym

x,yfor rad : Log EGeV 10. , 17.7828 , 31.6228 , 56.2341 , 100.

-0.1 0 0.1 0.2xm

-0.1

0

0.1

0.2

ym

x,yfor rad : Log EGeV 100. , 177.828 , 316.228 , 562.341 , 1000.

-1.5 -1 -0.5 0 0.5 1 1.5 2xm

-1.5

-1

-0.5

0

0.5

1

1.5

2

ym

x,yfor rad : Log EGeV 10. , 17.7828 , 31.6228 , 56.2341 , 100.

Askaryan pulses from air shower cores, Merida, 30th ICRC, July 10 2007 (Seckel)

Sample the Cerenkov Ring