EUSO P. Gorodetzky TAUP 2003

7/30/2019 EUSO P. Gorodetzky TAUP 2003

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P. Gorodetzky - TAUP 2003 - Seattle, Sept 5 - 9, 2003

Euso Project

Euso Physics

Detection of UHECR showers through fluorescence + Cerenkov

Euso detector : who is doing what ?

Acceptance et counting rates

q andE Horizontal showers and neutrinos

LPM effect

Euso status : NASA, ESA,

B phase and after

Conclusions

and the Lidar

P. Gorodetzky, J. Dolbeau, T. Patzak, E. Plagnol, P. Salin


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EUSO Physics I

Euso objective : Physics above the GZK effect

Extreme energies 1020-1021 eV physicsAstronomy through UHECR and neutrinos


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Euso Physics II

A non observation of the GZK effect would open the road to "new physics" :

Topological defects, Super-massive particules,

Lorentz invariance.

But does not close the door to a classical explanation :

Strong magnetic fields ( 0.1G et Fe) influence, (Astro-Ph/0209192v1) :

Magnetic fields generate isolation zones

(< 10 Mpc):

no exits, no returns

Isotropy

Caustics effects on the doublets.

High statistics are necessary


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Euso Physics III

The AUGER detector will solve the Agasa-Hires case

However, its rate (60evts/year for E>1020eV (if E-2.7)) will limit its ability

to study the UHECR above 1020eV.

WhateverAUGER solution is :

EUSO will be able to study, in a detailed manner, physics above the GZK

cutoff,

EUSO will be able to study the new physics (Super-GZK) or the ones of the

strong magnetic fields (isotropy, correlation).


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UHECR shower detection by fluorescence

Original idea by John Linsley in 1979 (Airwatch)

Large observation area, jumbo mass and, above 5 kmimmune from aerosols

A UHECR shower is seen as the displacement of a particules front.A fraction (


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The EUSO detector : Who does what ?

Optics : USAf 2m

Photo-detector : Japan

200000 pixels

Mechanics : France - Italy

Electronics : France - Italy

Analog - Digital

Ground Segment : Portugal

S.A. (LIDAR) : Switzerland- Italy


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US Optics I


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US Optics II


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French activities : LAPP, LPSC et APC/PCC Annecy Grenoble Collge de France

Analog electronics

Front End

Mechanics and thermal

study of the focal surface

Simulations - ESAF

Atmosphere

Analysis, LidarCommunication

OutreachF.Vannucci

Thermal conductivity of FSA(Summer, 6 m2, 850/200W)

Text-Tint


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Japan

Italy-Alenia

USA

And elsewhere

ESA

USA

Germany

(Munich)

calibrations


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Acceptance and counting rates I

Shower, detector and trigger simulation:

Shower production : Corsika -> parameterization GIL

Photons production : Fluorescence (Kakimoto et al.) and Cerenkov

Atmospheretransport : Rayleigh, Mie, Ozone (LOWTRAN7)

Optics : Transfers and aberrations

Photo-detectors : Filters and quantum efficiency

Trigger : Thresholds and persistence (Nthre, Npers)


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Acceptance and counting rates II

The absolute threshold is anchored by W and the detection efficiency.

The trigger performances determine the acceptance evolution versus energy.

The asymptotic efficiency will be

determined by the cloud coverage.

Efficiency times the power -2.7 law


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Clouds effects I

The cloud coverage will play an important role :

Eventually mask part of the shower (Smax

),

Increase the Cerenkov light reflection;

The cloud coverage is given by the ISCCP database : 280x280 km2 pixel size:

Longitude, latitude, every 3 hours --> altitude, albedo, cloud fraction.

AA Workshop

(GDR-PCHE)-----

LMD (X)

Weather forecast.

Aeronomy (Jussieu)

-----

CelesteHess

Magic

Auger

Euso


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Clouds effects II

Clouds reduce efficiency from 86% 53%

NO CLOUDS CLOUDS


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Clouds effects versus shower energy

E = 5 1019eV E = 5 1020eVE = 1020eV


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Duty cycle

Duty cycle (time fraction usable for measurements) depends on the "photon

background" :Without moon, this background is estimated (measured) to 300 ph/m2/nsec/sr

It originates from the stars light and to the "Airglow"

It does not depend critically on the cloud coverage ( +20%)

Moonlight will limit the duty cycle.

for12.8% of the time, moon is under horizon, for 18% light increase is insignificant,

for 25% light increase < 100 ph/m2/nsec/sr.

To that, too short nights have to be

removed (


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Counting rates

Super-GZK Hypothesis... Or GZK

12% --> 1000 events @ E>1020eV for 25 %

EUSO asymptotic acceptance (>1020eV) represents 5 and 10 times AUGERs


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A possible measurement (duty cycle 12%)

NevtGZK (E>1020eV) >100


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Angular resolution

Precise showers analysis will be made on an event by event basis: each shower

will get errors specifically depending of the observation conditions.As of today, only a statistical error estimation is considered.

Angularresolution : q < 1 ifqshower>60


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Horizontal showers and Neutrinos

Shower length depends on the encountered mass

Fluorescence production (O2

being a quencher) depends only on distance

(altitude < 15km)

Shower width (T) will then depend only on altitude.


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Neutrinos and Hadrons showers

The probability to observe an ( horizontal) hadronic shower with a maximum

under 10km is extremely weak.

Instead, this probability is maximum for neutrinos.


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Euso status : NASA, ESA,

International

NASA has given its OK to EUSO (if ESA ok) : 28 M$

Switzerland will take part to the Lidar study

Germany is officially part of EUSO : H.Teshima (Max Planck, Munich)

ESA

EUSO depends on 2 ESA managements: Science et Manned flights

ESA phase A has ended in July (instrument) and September (Lidar)

ESA committees will decree at the end the year on the project and its transition in

phase B

Management et Collaboration

Euso management structure will evolve : agencies consortium In France a collaboration with AUGER is taking form : AAA, fluorescence, flux

comparison, hybrid events Contacts also with AGASA and HIRES.


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Conclusions

EUSO physics are at the borders of new physics and of our universe understanding, via its

most energetic manifestations.

EUSO detector will be able, after AUGER, to study physics beyond 1020eV with importantstatistics (fluxes, correlations, GZK recovery,) whatever will be the AUGER results on the

Agasa-HiRes case.

Neutrino physics are within range.

Detection (optics, MAPMT) enhancement should allow a decrease of the detection threshold : 2-3 1019eV.

EUSO detector represents the first generation of spatial detectors using the atmosphere as

medium : USA and Japan are already studying the next generation.

The observable mass by EUSO is 2.0 1012 tons with a good transparency

it is an opening on future

At the international level, USA are waiting for the ESA decision.

All laboratories have played a strong role during PhaseA. They are ready to start phase B et

and be even more important there :

Electronics, mechanics, lidar, simulations and analysis...

We are all ready to take a very important place in this project.


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The atmospheric probe : a Lidar ?

Atmosphere is a complex medium and its exploitation (as a detector seen from space) is only

beginning.

Clouds (and other aerosols) treatment needs a control of the atmosphere conditions.A LIDAR(Light Imaging And Ranging) is the most efficient instrument for that : It allows an

(almost) direct measurementof the transmission coefficients.

It is however a complex tool, requiring an important electrical power.

For EUSO it is an important choice which is discussed !

Example of a Laser (355nm)

with EUSO as receiver

No clouds Subvisible clouds

A LIDAR will also allow a

statistical analysis of the clouds

presence

Altitude (km)Altitude (km)

(From G.Fiocco (Rome))

Documents

EUSO P. Gorodetzky TAUP 2003