GAMMA Experiment

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GAMMA Experiment
All-particle primary energy spectrum in the knee
region using an event by event method with the
GAMMA Experiment
4Y.Gallant, 1A.Garyaka, 5L.Jones, 1R.Martirosov,
2N.Nikolskaya, 3J.Procureur, 1S.Ter-Antonyan
1 Yerevan Physics Institute 2 Moscow Physics
Institute 3 Centre d Etudes Nucleaires
Bordeaux-Gradignan, 4 Universite Montpellier
II 5 University of Michigan
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GAMMA Facility
GAMMA Experiment

• Location
• Armenia, Mt.Aragats
• 3200 m a.s.l.
• EAS array
• 33x3 (1x1x0.05)m3
• 9(0.3x0.3x0.05) m3
• Muon hall
• 2500 g/cm2 of rock
• 150 (1x1x0.05)m3

• EAS data
• Nch gt 5 ?105 (100)
• R lt 25 m (50 m)
• ? lt 300
• N?(R?lt50m) gt 103
• E? gt 5 GeV
• T 6.2?107 sec

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Errors
GAMMA Experiment
at
EAS Simulations
CORSIKA6031(EGS, NKG)
SIBYLL2.1

• Emax 5103 PeV
• ? lt 300
• -1.5
• Ee gt 1 MeV
• E? gt 150 MeV
• E? gt 4 GeV (e/-)

N104
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Detector response
Density spectra

• s(7m lt ri lt 90m)

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Energy estimator
if

then
Statistic Errors
Methodic Errors
Let
CORSIKA
i1,104, A1,4
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E0-E1 plot
GAMMA Experiment
?2min(E0,E1)
x Ln(Nch),
y Ln(N?),
c cos(? )
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?A(E), ?A(E)
/ E0.5
(0.12) (-0.17 )
?? ?
? 0.13, ?? 0.03
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Error distributions
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All-Particle Spectrum
GAMMA Experiment