Telescope Array for Extremely High Energy Cosmic Rays.

July 30th, 2003Masaki FUKUSHIMAICRR, Univ. of Tokyo

Galactic Extra‐Galactic

HiRes: Composition Changefrom Heavy to Light

Ankle Structure

０

3

２

1

MagneticConfinement

ＡＧＡＳＡ：Ａｎｉｓｏｔｒｏｐｙ

towards Galactic Center

We are starting to collect

First samples of extra-galactic

Matter-Particles

Galactic to extra-galactic transition

Energy Spectrum of the Highest Energy Cosmic Rays

There is a Horizon forCosmic Rays with Energy

exceeding 10 20 eV

by GZK mechanism

Cosmic Rays with Energy above GZK cutoff exists.

No obvious astronomical counterpart within ~ 50 Mpc.

Log （ ENERGY ［ eV ］）

L

og (

FLU

X x

E3 )

AGASA

AGASA

Arrival Directions and Clustering “Point”

Sources

Isotropic Distribution

E > 10 19 eV

E > 10 19.6 eV > 10 20.0 eV

> 10 19.6 eV

> 10 19.0 eV

super-GZK + cluster

Hard to explain

by standardAstrophysics ・ Particle Physics ・

Cosmology

Possibilities of creating continued spectrum exceeding GZK-cutoff

mechanism reason signature

１Decay of super-heavy X

Particle （ big bang origin ）

concentration in

galactic halo

γ+ν

gal. center

２EHEν ＋Ｃ ν Ｂ → Ｚ０ Ｃ ν Ｂ over-density

in super-clusterγ ＋ ν

EHEν with extra-dimensionσ ～ 100 mB

（ shower in atmosph. ）

shower-profile

３ Violation of Lorentz inv. No Δ(1232) prod. proton 　

４“Ordinary” galaxies ；Excess in super-cluster

over-density ～１０within 50 Mpc

point source

5 Experimental Problem? Statistics, SystematicsAcceleration problem unresolved for 2-4.

Establish・　 Galactic to Extra-galactic

transition

Confirm / Refute・　 super-GZK

・　 cluster

“AGASA” x 10 Plastic Scintillator Array

+3-station “HiRes”

Fluorescence Telescope +

Low energy extension

20 km

20 km

Millard CountyUtah/USA

24 x 24 Scintillators(1.2 km spacing)

AGASA x 9

3 x Fluorescence StationsAGASA x 10

TA Detector Configuration Exp Res.

AGASA 1.60

TA SD ~1.00

TA FD 0.60

TA Hyb. 0.40

Low Energy HybridExtension

Energy Calibration by SD-FD Coincidence Meas..

SD - FD ；　 Two Independent Methods for Energy Determination.

○ 　 E 　 > 　 1019 eV ~ 100 ev. / Year 　　○ 　 E 　 > 　 1020 eV ~ 1 ev. / Year

Phase-1 Hybrid TA gives ENERGY SCALE by ● 　 SCINTILLATOR ARRAY● 　 AIR FLUORESCENCE

　　　　　　　　　　　　 Energy Spectrum by Only-one, Unique Energy Scale

（ Systematic Energy Uncertainty 　＜　１０％　 Aimed ）

Calibration

e /γ meas.

Comparison

　　　　 proto: 50 cm x 50 cm, 1cm thick　　　　　　 Wave Length Shifter Fiber readout 　　　　 50 modules used in L3 for 2.5 years.

WLS: BCF-91A（ 1 mm Φ ）

cutting 1.5 mm deep groove

Final: 3 m2 by 2 PMT readout.

TA Scintillator Development

Energy Loss in the Air “μ” Density at 1km for p/Fe

AUGER water tank simulation

ｐ Ｆｅ

EA

IR /

E0

~10% ofTotal Energy

~90% ofTotal Energy

MODELp / Fe

Uncertainty

Plastic Scintillator: 　　　　　　　　　　　　　 　 Water Tank:

e ＋ e － μ ＋ μ － & soft γ

Electron Measurement by Scintillator● 　 Reasonable resolution● 　 Small model / composition dependence

Imaging Camera ：１６Ｘ１６ PMT Array

Electronics ：２００ ns continuous ADC

＋Signal recognition

by software

Shower Image

1 0 x 1 0 FoV/PMT

Telescope ：　３ｍ Φ 　Spherical Mirror

TA Telescope Development

①

③②

３ independent energy meas.for 60% of events at 1020 eV

　　 Estimate of Systematics　　　　・　 Atmosph. Clarity　　　　・　 Cherenkov Light

3 Fold Stereo Measurement

Shoot electron Linac beam into the sky.

20 MeV / particle x 109 ppp = 2 x 1016 eV total energy deposit. Absolute End-to-End energy calibration. Feasibility study

20 MeV 40 MeV100 m away 100 m away

望遠鏡

カメラ 東工大：垣本・荻尾、　愛媛大：吉井、　武蔵工大：門多望遠鏡躯体・回路・インフ

ラ

ＩＣＲＲ：福島・瀧田・林田・大西・桜井・大岡・下平・鳥居、ＭＰＩ：手嶋＊＊

大気較正 近畿大：千川、　通総研：篠野回路・ＤＡＱ 全般 ＫＥＫ：松田・藤井・田中・新井＊、長崎総科大：田中＊

地表検出器

検出器大阪市大：川上・林・吉越、　広島市大：田中、　高知大：中村

ＡＧＡＳＡ較正 山梨大：本田・橋本・石井

回路・ＤＡＱ 千葉大：吉田・河合、　放医研：内堀・安田Simulation　 & Analysis

－埼玉大：井上、　芝工大 : 笠原、　神奈川：日比野、東大：寺沢＊＊

合計　３１ 名　　　　　米国　　　　　　

サイト Utah: P.Sokolsky(**), K.Martens, C.Jui, J.Mathiews, Z.Cao

Rutgers: G.Thomson,S.Schnetzer, 　 Montana: J.Belz,

（英国） Leeds: A.Watson**

合計　９ 名

Participants

* : Ａｄｖｉｓｅｒｓ ** : Kakenhi Reviewers

Construction Plan of Hybrid TA:

AGASA

HiRes

AUGERAUGER

SD only

SD + FD

constructionobservation

2003

SITE PREPARATION

TELESCOPE TEST IN UTAH

ARRAY PRODUCTION

ARRAY TEST IN UTAH

TELESCOPE INSTAL.

TELESCOPE PRODUCTION

ARRAY PRODUCTION

Start Hybrid Obs.

CALIB. with AGASA

Start Obs. with SD only

Telescope Array ; Summary

1. Well-defined purposes; ① 　 Establish galactic to extra-galactic transition. ② Confirm/Refute cluster + super-GZK.

2. Seamless coverage from 1016 to 1020.5 eV.

3. Fluorescence + Surface hybrid.

4. Common technology and existing resources based on AGASA + HiRes.

5. Start measurement in 2006(SD) / 2007(+FD).