280 likes | 437 Views
The Tunka Cherenkov Array. Д.В.Чернов, Е.Е.Коростелева, Л.А.Кузьмичев, В.В.Просин, И.В.Яшин НИИЯФ МГУ, Москва, Россия Н.М.Буднев, О.А.Гресс, Т.И.Гресс, Л.В.Паньков, Ю.В.Парфенов, Ю.А.Семеней НИИПФ ИГУ, Иркутск, Россия Р.В.Васильев, Б.К.Лубсандоржиев, А.И.Панфилов, П.Г.Похил
E N D
The Tunka Cherenkov Array Д.В.Чернов, Е.Е.Коростелева, Л.А.Кузьмичев, В.В.Просин, И.В.Яшин НИИЯФ МГУ, Москва, Россия Н.М.Буднев, О.А.Гресс, Т.И.Гресс, Л.В.Паньков, Ю.В.Парфенов, Ю.А.Семеней НИИПФ ИГУ, Иркутск, Россия Р.В.Васильев, Б.К.Лубсандоржиев, А.И.Панфилов, П.Г.Похил ИЯИ РАН, Москва, Россия C.Spiering, R.Wischnewski, DESY Zeuthen, Zeuthen, Germany
The Tunka-25 array in 2003 25 QUASAR-370 tubes - 37 cm diameter - integrating 4 EMI D668 tubes - 20 cm diameter - fiber read-out, - FADC „Far detector“
EMI D668 for pulse form analysis - PMTs - fibers - optical receivers - FADCs ...... from DESY
Measured waveform and parametrization Time code in units of 2 nsec
Sample of atmospheric Cherenkov light pulse EXPERIMENT: FFALL(T)=AQM·exp(-(T-TQM)/TFALL), for T > TQM FFRONT(T)=exp(-((T-TQM)/TFRONT)2)·FFALL(T), for T≤TQM
Measured FWHM as function of Left: distance shower-axis PMT Right: zenith angle of shower
Correlation between depth of shower maximum and pulse width at different distances R to the shower axis (Corsika)
FWHM as function of shower energy Assuming that the data describe Helium, the dashed curves are expected for protons and Iron, respectively
Corsika,2000 m Light intensity This part depends mainly on distance to shower maximum up to R~ 30 m: exponential This part depends mainly on energy E = 2 PeV
The same dependence as measured in QUEST Control experiment at Gran Sasso (EAS Top), with the number of electrons measured by scintillation counter
up to R~ 30 m exponential R1 Corsika and parametrization One free parameter: P
Тheoretical accuracy of energy reconstruction protons Empty circles: protons Full circles: iron iron
CORSIKA: Measurement of a distance to EAS maximum with the Cherenkov light LDF steepness parameter P σHmax = 0.3 km mean shift: ΔH = 0.15 km for p ΔH = - 0.15 km forFe Hmax= 10.62 - 0.12·(P+2.73)2 , [km]
CORSIKA:Measurement of relative position of EAS maximum with Cherenkov light pulse FWHM at R=250 m from shower axis (X0/cos(θ) – Xmax)= 1659 – 1006 · log10(FWHM/ns), g/cm2
Results: • 200 hours Tunka-25 • 1.5 million triggers • 160 000 events with E0 > 6·014 eV and < 25° • Fit Q(R) and determine Q1, P, • shower maximum • energy and atomic weight
KASCADE TIBET
e 1-2 m The future 1. 10 m² water tank (muons at 200 m distance, 10-100 PeV showers) 2. Tunka-133, with 1 km² area µ 3 m
The Tunka-133 Project Photomultipliers – 20 cm EMI with FADC read-out 19 clusters, each with 7 huts Energy range: up to 1018 eV
TUNKA-133 Expected statistic from 1 year operation ( 400 hours): > 3·1015 eV ~ 3.0 •105 events > 1017 eV ~ 200 events > 1018 eV ~ 5events