RICE David Seckel, NeSS02, Washington DC, Sept. 19-21,/2002 R adio I ce C herenkov E xperiment PI presenter

David Seckel, NeSS02, Washington DC, Sept. 19-21,/2002

RICERadio Ice Cherenkov Experiment

PI

presenter


RICENeSS: 10 min + 2

• Concept

• Status

• Results (astro-ph/0206371)

• Future


RICERadio Detection of High Energy Neutrinos

Goals

PeV: AGN 1 km3

EeV: GZK 103 km3

Cherenkov radiation from induced in-ice shower

Signal ~ Q ~ 0.25 Es/GeV ~ RM ~ 10 cmTransparency > 1 kmThermal noise @ 250 k

.8 km


RICEEeV neutrino detection with RICE

5 km

1-10 PeV 1-10 EeV _

Signal Strength Ice PropertiesCalibration LPM effecte e N recoil hadrons0s interact


RICE

• 16 Rx (10 cm dipole)• 5 Tx• 3 Horns• 4 Oscilliscopes (x4) • DAQ• PCs• Pulse Generator• Dry hole

Pole:

• Network analyzer• Antenna range

Kansas:

Deployment


RICEChannel and DAQ configuration

Power

Scope

Trigger generator

Antenna

Amp in PV

cableAmpFilter

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


RICESingle Channel Calibrations

200-500 MHz: +/- 3 dB (E)

TX….RX • antenna + amplifier calibrations• cable (TX, RX) and filter• relative geometry of TX/RX (r,


RICEMonte Carlo Simulation

• Neutrino interaction

• e+/e-/ shower

• Radio pulse generation

• Propagation through ice

• Antenna & DAQ response


RICEInteractions and Event types

• Interaction Model– isotropic flux from upper hemisphere (2sr)

– charged and neutral currents

– hadronic energy = y E, lepton energy = (1-y) E

– Gandhi et al. ’98 cross-sectiond/dy with ~20% reduction for Oxygen (EMC effect)


RICEShower Simulations

• Shower simulation– GEANT 3.21 (100 GeV – 1 TeV)

30% smaller than ZHS (but …GEANT 4 ??)

– Extrapolate to higher energies

– LPM from Alvarez & Zas

– Hadronic cascades convert

completely to EM with no

LPM

– EM & hadronic cascades

treated separately

Average 100 GeV shower


RICEEM Pulse generation

ALSO: Experimental results (Saltzberg, et al.) confirms coherence and Askaryan effect

1. Pulse increases with Energy2. Narrows with frequency3. Some small numerical

differences between codes


RICERadio Attenuation in Ice

Red – Westphal (Greenland) + Matsuoka (high freq)Black – Kawada(lab) + Matsuoka (high freq) (from Matsuoka)

0.1 0.2 0.5 1 2 5 10nHGHzL

0.0005

0.001

0.002

0.005

e''

temp = - 10

0.1 0.2 0.5 1 2 5 10nHGHzL0.0001

0.000150.00020.00030.00050.00070.001

0.00150.002

e''

temp = - 25

0.1 0.2 0.5 1 2 5 10nHGHzL0.00002

0.00005

0.0001

0.0002

0.0005

e''

temp = - 50

’ + i”

0.1 0.2 0.5 1 2 5 10nHGHzL

0.1

1

10

100

1000

lttaHmkL

lH- 60 CLx 100

lH- 50 CLx 10

lH- 40 CLx 1

Solid – Provorov (used by RICE)Dashed – Matsuoka + Westphal

RICE bandpass


RICEPulse shape simulation

Disc. threshold

Background taken from data sample


RICEResults of MC simulation

Limited by attenuation

60,000 e- showers at E = 1 EeVBlack dots – sampleRed dots – events which would trigger RICE

~ 5% efficiency

Limited by Cherenkov angle


RICE

1. 2. 3. 4. 5. 6.Log@EsDHPeVL- 3.

- 2.

- 1.

0.

1.

2.

goL@V ffeDHmk3 L

RICE effective volume for e-, showers

Range due to varyingsignal strength by 0.5-2

Range due to varyingattenuation by 0.5-2

Mul

tipl

y by

2

sr

This is appropriatefor e chargedcurrent events.


RICE

1. 2. 3. 4. 5. 6.Log@EsDHPeVL- 3.

- 2.

- 1.

0.

1.

2.

goL@V ffeDHmk3 L

LPM and hadronic showers

With LPMWithout LPM

“Hadronic”Es = 20% E


RICEReconstruction of transmitter events

• t =50 ns for noise• t = ns for

• r = 10 m nearby• r = 0.1 R , < 1 km

• ~ 10 deg• E/E ~ 0.5


RICEResults of Data Analysis

333.3 hrs livetime


RICELimits on diffuse e flux from e- showers

a) Stecker & Salamon (AGN)b) Protheroe (AGN)c) Mannheim (AGN)d) Protheroe & Stanev (TD)e) Engel, Seckel & Stanev (GZK)

Ranges are central 80%


RICELimits derived from e- showers (e CC)hadronic showers (all CC+NC)

a) Stecker & Salamon (AGN) d ) Protheroe & Stanev (TD)b) Protheroe (AGN) e) Engel, Seckel & Stanev (GZK)c) Mannheim (AGN)

Ranges are central 80%


RICENear term future

Beginning analysis of ~ 1 yr of data. Improve limits by ~ 10.


RICELonger term

100 GZK events/yr requires ~ 1000 km3 (1 Eg)

RICE: LPM no LPM

Auger: tau e, muLPM

LPM

Needs

SaltEUSO

ANITA

AMANDA/ANTARES

IceCube/NEMO


RICESummary

• Radio detection has a bright future• Demonstrated ability to reject surface backgrounds and work close to

thermal limit• Major uncertainty is

– attenuation in ice (high energy)– calibration (low energy)

• Veff (E > 1018eV) > 20 km3 sr [e CC only]• Limit improves by 2-18 with inclusion of hadronic channels,

depending on spectrum.• Limits may improve by 10 (again) with analysis of 1 yr data.• 100 GZK events per yr is conceivable


RICE

Intentionally left blank

End of Talk


RICEThermal Background

-4 -2 0 2 4

-4

-2

0

2

4

-0.8 -0.4 0.0 0.4 0.8

-0.8

-0.4

0.0

0.4

0.8

y (k

m)

x (km)

y (k

m)

x (km)

Red – Simulated detected showers (1 EeV)Black – Simulated noise – uncorrelated background

Warnings: shower vertices are “true” positions not reconstructed. Should be OK inside 1 km.shower vertices are monoenergetic.


RICESystematic Effects (see astro-ph/0206371)

Documents

RICE David Seckel, NeSS02, Washington DC, Sept. 19-21,/2002 R adio I ce C herenkov E xperiment PI presenter