CODALEMA A Cosmic Ray Radio Detection Array ICRC 2007, 3-11 July Merida, Mexico CODALEMA A Cosmic...

CODALEMAA Cosmic Ray

Radio Detection Array

ICRC 2007, 3-11 JulyMerida, Mexico

CODALEMAA Cosmic Ray Radio Detection Array

Didier Lebrun , LPSC Grenoble & CODALEMA Collaboration




CODALEMA

Didier Lebrun, LPSC Grenoble

Project

Observation of Transient Eventswith Digital Radio astronomy

StellarSolar & Planetary (icrc0337)

Atmosphere

Cosmic Ray Radio Detection

• Telescope deployment (icrc0161)

• Study of Radio emission (icrc0460)

• Large Array R&D (icrc0339)

Collaboration

~25 persons from 8 French Labs

Particle & Cosmic Ray PhysicsSUBATECH, NantesLAL, OrsayLPSC, GrenobleRadio AstronomyLESIA, Observatoire de ParisUSN, NançayLAOB, BesançonAtmospheric PhysicsLPCE, OrleansElectronicsESEO, Angers




EAS Radio Detection


40 years after first successfull experiment in Jodrell Bank

EAS Radio Detection revisited since 2004 fromo LOPES in Karlsruhe

o CODALEMA in Nançay

New Phase: Characterization of EAS Radio emission CODALEMA : 3 years funded ANR program since 2006

To Develop and Deploy for cosmic ray studies: Ground Particle Detector Array

to trig and calibrate radio signal New Radio Antenna Array

from huge log antennas to small linear antennas

COsmic ray Detection Array with Logarithmic Electro-Magnetic Antennas Linear




Radio Astronomy Observatory in Nançay


Large Radio Telescope Decametric Network

Heliograph station CODALEMA




Array Lay Out





DAQ


T

TRIGGERHG

600 nsGate

All detectors Wired to Central DAQ

“MATACQ” Digitalizing Cards 1 Gs/s 12bits , 2560 points. 1V max13 Scintillators

2 PMTs High Gain andLow Gain per station

Clock

16 Antennas

14 EW+1 Cross




Scintillator Array : Data processing


Signal analysis

•Calibration with VEM

• Arrival Direction: TOF/stations•Arrival time: Plane shower front

• Shower Size :Integrated pulse/station /VEMLDF fit with NKG function

• Shower Core: Internal ( /external)Trigger select:Central counter>surroundings)

distribution




ScintillatorArray :EAS Energy Estimation


‘Vertical Equivalent Shower Size’

Use of Constant Intensity Cut CIC Method

From simulations (AIRES) :

E= 2.14 1010 N0 0.9

E/E = 32% @ 1017 eV

Scintillator Array Energy SpectrumInternal Events

log E (eV)

sec bins

N()

Inte

nsit

y

coun

ts




Radio Array : Active Dipole Antennas


Low Noise AmplifierLow Noise Amplifier

ASIC BiCMOS 0,8 High Input Impedance BW(3dB)=200MHz GLNA=34 dBInput Noise: 1.3 nV/VHz

Z input = 10 pFTransmission S~1 (<100 MHz)

Short Dipole L< Short Dipole L< - ~Isotropic(<Res)- Smooth responseEffective Length Voc = L L ..E ActiveActiveLow induced current - Needs amplifierZ Pure capacitive -Matching Load

L=1.2 m h=1.0 m

res ~ 115 MHz

Gain ()

50 MHz

HPBW=60°

Eff. Length (dB meter)at Zenith

L= L . S . GLNA

MHz




Calibration: Interferometric measurementwith sky source


Correlation Dipole- Decametric Array during Cas A Transit

See ICRC339 Poster, B.Revenu




Radio Frequency Background on Site


LNA Noise

Analyzer noise

FM

ExpectedSky NoiseWith Dipole L

Filter BW




Tagging AntennasDigital Filtering in 23-85 MHz Band


Scintillator Array Trigger Event=43° =39°

Labelled ‘external’logE~18.3

AssociatedRadio event=39.5° =32°

Scint/Radio wave front= 6.5°t = 7.5 ns




EAS Radio Event Validation


Particle and Radio Shower Front Coincidence




Signal in Filtered bandand Spectrum in Full band


Raw EAS Event

Random Trigger

0 Frequency 200 MHz

mil

li-V

olts

•Signal amplitude analysis in filtered band [23-85]

•Spectral dependence information in Full band (analysis in progress)

Log

(P

ower

/MH

z) a

rb.u

nits

-500 0 500 nanoseconds




Conclusions


CODALEMAA Radio Detection Array with Active Dipole Antennas,Coupled with a Scintillation Counter Array was described.

CODALEMA is now running in Nançay to study EAS radio emission at energy E~1017 eV

Results will be presented in icrc0420

CODALEMA further developments includeMore antennas in NS for Polarization studies (on going this year)Increase ground array size (on going this year)New semi-autonomous antennas (2008, embedded DAQ, not self-powered)Self-triggering radio systemSolitary Antenna system R&D for very large arrays

CODALEMA A Cosmic Ray Radio Detection Array ICRC 2007, 3-11 July Merida, Mexico CODALEMA A Cosmic...

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