Transcript AGASA

Telescope Array for
Extremely High Energy Cosmic Rays.
July 30th, 2003
Masaki FUKUSHIMA
ICRR, Univ. of Tokyo
Galactic
Extra‐Galactic
Magnetic
Confinement
1
０
HiRes: Composition Change
from Heavy to Light
Ankle Structure
3
２
ＡＧＡＳＡ：
Ａｎｉｓｏｔｒｏｐｙ
towards
Galactic Center
Galactic to extra-galactic transition
We are starting to collect
First samples of
extra-galactic
Matter-Particles
Energy Spectrum of the Highest Energy Cosmic Rays
There is a Horizon for
Cosmic Rays
with Energy
exceeding 10 20 eV
Log ( FLUX x E3)
AGASA
by GZK mechanism
Log（ENERGY［eV］）
Cosmic Rays with Energy above GZK cutoff exists.
No obvious astronomical counterpart within ~ 50 Mpc.
Arrival Directions and
Clustering
“Point”
Sources
E > 10 19 eV
AGASA
E > 10 19.6 eV
> 10 20.0 eV
> 10 19.6 eV
> 10 19.0 eV
Isotropic Distribution
super-GZK + cluster
Hard to explain
by standard
Astrophysics ・ Particle Physics ・ Cosmology
Possibilities of creating continued spectrum exceeding GZK-cutoff
mechanism
Decay of super-heavy X
１
Particle （ big bang origin）
EHEν＋ＣνＢ →
reason
signature
concentration in
galactic halo
γ+ν
gal. center
ＣνＢ over-density
Ｚ０
in super-cluster
２
γ＋ν
σ～100 mB
（shower in atmosph.）
showerprofile
３ Violation of Lorentz inv.
No Δ(1232) prod.
proton
“Ordinary” galaxies；
４
Excess in super-cluster
5 Experimental Problem?
over-density～１０
within 50 Mpc
point
source
EHEν with extra-dimension
Statistics, Systematics
Acceleration 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
TA Detector Configuration
Exp
AGASA
TA SD
~1.00
TA FD
0.60
TA Hyb. 0.40
Millard County
Utah/USA
20 km
Res.
1.60
24 x 24 Scintillators
(1.2 km spacing)
AGASA x 9
3 x Fluorescence Stations
km
AGASA20
x 10
Low Energy Hybrid
Extension
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
e /γ meas.
Calibration
Comparison
Energy Spectrum by Only-one, Unique Energy
（Systematic Energy Uncertainty ＜ １０％ Aimed）
Scale
cutting 1.5 mm deep groove
TA Scintillator Development
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 ）
Final: 3 m2 by 2 PMT readout.
Energy Loss in the Air
“μ” Density at 1km for p/Fe
EAIR / E0
~10% of
Total Energy
MODEL
p / Fe
Uncertainty
~90% of
Total Energy
Plastic Scintillator:
e＋e－
ｐ
Ｆｅ
AUGER water tank simulation
Water Tank:
μ＋μ－ & soft γ
Electron Measurement by Scintillator
● Reasonable resolution
● Small model / composition dependence
Telescope： ３ｍΦ Spherical Mirror
TA Telescope Development
Electronics：
２００ ns continuous ADC
＋
Signal recognition
by software
Imaging Camera：１６Ｘ１６ PMT Array
Shower Image
1 0 x 1 0 FoV/PMT
3 Fold Stereo Measurement
①
３ independent energy meas.
for 60% of events at 1020 eV
Estimate of Systematics
・ Atmosph. Clarity
・ Cherenkov Light
②
③
Shoot electron Linac beam into the sky.
20 MeV
100 m away
40 MeV
100 m away
20 MeV / particle x 109 ppp = 2 x 1016 eV total energy deposit.
Absolute End-to-End energy calibration.
Feasibility study
Participants
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・ ＩＣＲＲ：福島・瀧田・林田・大西・桜井・大岡・下平・鳥居、
回路・インフラ ＭＰＩ：手嶋＊＊
望遠鏡
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＊
検出器
地表検出器
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
* : Ａｄｖｉｓｅｒｓ ** : Kakenhi Reviewers
Construction Plan of Hybrid TA:
2003
SITE PREPARATION
TELESCOPE TEST IN UTAH
TELESCOPE PRODUCTION
TELESCOPE INSTAL.
ARRAY TEST IN UTAH
ARRAY PRODUCTION
ARRAY PRODUCTION
CALIB. with AGASA
SD only
Start Obs. with SD only
Start Hybrid Obs.
SD + FD
AGASA
HiRes
AUGER
AUGER
construction
observation
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).