1 Cosmic Ray Composition in the Knee Region H. Tanaka GRAPES-3 Collaboration
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Cosmic Ray Composition in the Knee Region
H. Tanaka
GRAPES-3 Collaboration
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Cosmic Rays
High Energy Particle from outside of the Earth 107~1020eV Power Low Spectrum E
- γ
Particle Type Electron, Proton ~ Iron
Origin SNR?
Energy Spectrum
TeV PeV EeV ZeV
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Knee in Energy Spectrum
What is the cause of knee ?Limit of AccelerationLeakage from the Galaxy or others
1015eV
Measurement of nuclear composition and their energy spectrum could be one of the key to the solution.
H
Fe
?
H
Fe
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Air Shower Experiments
Tibet ASγ
KASCADEGRAPES-3
GRAPES-3 KASCADE Tibet ASObs. Height 2200m 100m 4300m
Density of Particle Detector
1det / 55m2
1.8%1det / 167m2
1.3%1det / 56m2
0.9%
Other Observations
560m2 Muon Det. 800m2 Muon Array300m2 Hadron Det.
128m2 MTT etc.
80m2 Burst Det.
Features Larger StatisticsLower E Threshold
Larger Statistics Lower E Threshold
GRAPES-3 has both of dens array and large muon detector at the high altitude.
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SC MU
GRAPES-3 Experiment Location: Tamil nadu, Ooty 2,200m (800g/cm2)
Charged Particle (electron) Detector: Plastic Scintillator 1m2, 5cm thick x400 (8m separations)
Muon Detector:16 detectors (>1GeV) total 560m2
Observation:The number of electrons and the number of muons
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Shower SizeSize Spectrum
Energy? Composition? MC, muon
LOG
LO G
N2.
5 dI/
dN [m
-2sr
-1s-1
N1
.5]
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1
2
3
4
5
6
3 4 5 6 7 8LOG10(Ne)
LOG10(N
μ)
H 1014eV
H 1015eV
H 1016eV
Fe 1014eV
Fe 1015eV
Fe 1016eV
Energy
Nuclear Number
γ 1014eV
γ 1015eV
γ 1016eV
Particle Type and Energy Estimated from Observations (MC)
Estimation of primary energy and nuclear mass number from the numbers of electrons and muonsModel dependency for HE-Hadronic interaction
Air Shower Simulation
Hadronic Interaction Model
* SYBILL 2.1* QGSJET01
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N- Ne diagram (M.C.)
M.C. simulation CORSIKA QGSJET01, SIBYLL2.1,
QGSJET-II
5 nucleousProton, He, N, Al,FeObservation
<n
um
ber
of
dete
cte
d
mu
on
s>
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Multiplicity DistributionAl / Fe is fixed to 0.8
Ne: 105.0 - 105.2
marker Proton 0.3 He 0.4 N 0.3 Al 0.02 Fe 0.03 ObservationGood sensitivity of
cosmic ray mass
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Energy Spectra Analysis
1
10
100
1000
4 5 6 7Log10(Ne)
dI/dNexNe2.5
ALLHHeNAlFe
MC
Log10(Ne )
Log1
0(E
/TeV
)
QGSJET
Log(E)
dI/
dE・E
2.5
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All-particle Spectrum
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Proton Spectrum
Comparing with direct measurements is possible
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Other Spectra
He N
Al Fe
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Mean Mass Number
Lower threshold enables data to compare with direct measurements.
H
Fe
He
N
Al
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SummaryGRAPES-3 can get energy spectra of five groups utilizing muon multiplicity distribution.
Change in proton spectrum and increase in mean mass with energy observed
The results with SIBYLL and QGSJET-II agree with direct and KASCADE measurements.
Extend spectrum to higher energy
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THANK YOU
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Air Shower Experiments
Tibet ASγ
BASJE
KASCADE
GRAPES-3 SPASE-2
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Method of EAS Observation
BASJE Bolivia (550g/cm2)
46 SDs (1 or 0.83 m2 each)
12 SDs (4 m2 each)
SPASE-2 South Pole (695g/cm2)
30 SDs (0.8m2 each)
KASCADEKarlsruhe (1020g/cm2)
252 SDsCentral DetectorMuon Tracking Detector
Tibet AsγTibet (606g/cm2)
500 SDs (0.5m2 each)
Emulsion chamber Burst detector
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Method of EAS ObservationLocation EAS Array
GRAPES-3 Ooty
800g/cm2
400 SDs
(1m2)
BASJE Chacaltaya
550g/cm2
46SDs(1m2)
12SDs(3m2)
SPASE-2 South Pole
695/cm2
30 SDs
(0.8m2)
KASCADE Karlsruhe
1020g/cm2
252 SDs
(3.2m2)
Tibet ASγ Yangbajing
606g/cm2
789 SDs
(0.5m2)
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Low Flux of Cosmic Ray around Knee
Low Flux 1 particle in 1m2 in a year
(>1015eV) Poor statistics in Direct
Method Air Shower Observation
above 1015eV
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Important Matters in Observing Cosmic Ray around Knee
To get enough statistics (Lower flux for higher cosmic rays)
1 particle in 1m2 in a year Air Shower Observation above 1015eV
Sensitivity of Cosmic Ray Mass The number of Muon
Large Area Muon detector
Solve the Uncertainty of Monte Carlo (high energy phenomena)
Compare the observation with direct measurements Density Shower Array for lower threshold energy
GRAPES-3 Experiment
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The First Report of Knee
“On the Size Spectrum of Extensive Air Showers”
G.V. Kulikov and G.B. KhristiansenJournal of Experiment and Theoretical Physics, 1958Break of size spectrum was reported between 106 – 107.
The cause of knee is not yet clear for 50 years.
How are Recent Observations?
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Energy Spectrum
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Air Shower Observation
Primary particle
Observation
Muon Detector Particle Detector Array
, e
Low Energy Particle60GeV
High Energy Particle>1013eV
ATMOSPHERE
GROUND
MC
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Direct Measurements
JACEE Japanese American
Cooperative Emulsion Experiment
Balloon Experiment 1 - 1000 TeV The Antarctic
Emulsion Chamber X-ray film Lead Plate
RUNJOB RUssia Nippon JOint
Balloon experiment Balloon Experiment
10 - 1000 TeV Kamchatka to Moskva
JACEE
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Mean Mass Number
Much difference among them!
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Important Matters in Observing Cosmic Ray around Knee
To get enough statistics (Lower flux for higher cosmic rays)
Sensitivity of Cosmic Ray Mass
Solve the Uncertainty of Monte Carlo (high energy phenomena)
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サイズ推定(横方向フィット)
x = -11.8m y = 27.3m s = 0.91
シャワーサイズ1.82×105
コアからの距離 (m)
検出
粒子
数検
出粒
子数
LOG
5.40.2
1
s
m
s
m r
r
r
rr
NKG 関数
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ミューオントラック検出装置検出装置 1 層 58 本の比例計数
管 (6m×10cm×10cm) 交互に組まれた 4 層で
トラックを識別 合計 16 台 (560m2) E>1GeV
4 layers
58 counters6m
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EAS DataObservation 2000 – 2001 (560days) Shower Number 6×108
Shower Rate 13Hz
Shower Selection Core Location (>80m) Zenithal Angle θ < 25o
Monte Carlo Simulation CORSIKA
QGSJET-II (CORSIKA6.50)
SIBYLL 2.1 (CORSIKA6.50)
QGSJET01 (CORSIKA6.02)
Primaries Proton, He, N, Al and Fe
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Expanded GRAPES Collaboration(1) TIFR, Mumbai: H.M. Antia, S.K. Gupta, P.K. Manoharan, P.K. Mohanty,
P.K. Nayak, H. Tanaka, S.C. Tonwar
(2) Osaka City University, Japan: S. Kawakami, Y. Hayashi, S. Ogio, A. Oshima
(3) Aligarh Muslim University, Aligarh: Shakeel Ahmad, Badruddin, R. Hasan
(4) APS University, Rewa: A.P. Mishra, P.K. Shrivastava
(5) BARC, Mumbai: R. Koul, G.N. Shah
(6) J.C. Bose Institute, Kolkata: S. Ghosh, P. Joarder, S. Raha, S. Saha
(7) Gauhati University: R. Baishya, A.G. Baruah, K. Boruah, P.K. Boruah, P. Datta,
J. Saikia
(8) IIA Bangalore: D. Banerjee, P. Subramanian
(9) North Bengal University: A. Bhadra
(10) R.D. University, Jabalpur: R. Agarwal, S.K. Dubey, Santosh Kumar
ENDThanks for your kind attention!
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The Number of Electron and Muon
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Target for present experiment getting the size spectrum and muon multiplicity
distribution Using M.C., energy spectrum of nucleus can
be deduced from these results
To achieve this, compact array (high density SD) and muon detectors with large area are required.
In this experiment our energy range is overlapping with direct measurement (Balloon exp.). It means we have an anchor point, even though our results are totally M.C. dependent.
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Location of GRAPES-3 Ooty Air Shower Experiment
•Location Mt. Ooty, South India E 76.7° N 11.4°2,230m a.s.l. (800g/cm2)
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Future Expansion Plansto observe higher energy cosmic rays
Radio Telescope(326MHz)
Shower Array
1km2 Array
Muon Detector
New Muon Detector
Radio Array (30-70MHz)
100m2 Hadron Calorimeter
Neutron Monitor
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空気シャワーシミュレーションCORSIKA
ハドロン相互作用モデル DPMJET
GRT + minijet HDPM
現象論的モデル neXus
GRT + minijet QGSJET
GRT + minijet 空気シャワー向け
SIBYLL minijet 空気シャワー向け
VENUS GRT ( Gribov-Regge Theor
y )
110m a.s.l.2-D Half maximum
D.Heck et al., Proc. ICRC27, 233, 2001
電子数
ミュ
ーオ
ン数
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ハドロンモデルの影響
1 PeV 鉄
電子数 ミューオン数
両者とも ~ 10% 程度の違い
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OBS
QGSJET Proton
SIBYLL Fe
QGSJET Fe
SIBYLL Proton
ハドロンモデル依存性
CORSIKA QGSJET SIBYLL
Log( サイズ)
<検
出ミ
ュー
オン
数>
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Knee のモデル
1. 超新星残骸での加速2. 超新星衝撃による加速3. 斜め衝撃波による加速4. 多様な超新星による加速5. 単一の超新星残骸での加速6. 銀河風での再加速7. 火の玉モデル
8. 銀河からの漏れ出し9. 銀河からの異常拡散10. 銀河磁場中の拡散と漂流11. 乱流銀河磁場中の移流拡散12. 拡散漂流モデル
13. 光分裂と拡散14. ニュートリノとの相互作用
加速 伝播
相互作用
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Shower Cascade in the AtmosphereAir Shower Phenomena
Nuclear Cascade p, n, , 0, K, K0, …
[decay] 0 + [8×10-17sec]
+ () [3×10-8sec] High Energy: COLLISION Low Energy: DECAY
Electromagnetic Cascade Pair Creation e+ + e-
Bremsstrahlung ee +
Primary particle
Observation
air
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個々の成分の比較
個々の成分で比較できる!
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シャワー到来方向
検出器へ粒子の入射する時間差から到来方向を推定するガンマ線点源の観測時の際は重要
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シャワー到来方向推定時
間差
(ns
ec)
(m)
EAS DataObservation 2000 – 2001 (560days) Shower Number 6×108
Shower Rate 13Hz
Shower Selection Core Location (>80m) Zenithal Angle θ < 25o
Monte Carlo Simulation CORSIKA
QGSJET-II (CORSIKA6.50)
SIBYLL 2.1 (CORSIKA6.50)
QGSJET01 (CORSIKA6.02)
Primaries Proton, He, N, Al and Fe
The Number of Electron and Muon