Status and first results of the KASCADE-Grande experiment ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Outline Motivation for KASCADE-Grande Experimental set-up Reconstruction of EAS with KASCADE-Grande First Analysis ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

? Motivation for KASCADE-Grande energy spectrum and composition 1016eV-1018eV: iron knee ? origin of the knee ? galactic to extragalactic transition? Testing hadronic interaction models Anisotropies ? ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE’s results: KASCADE Main results keep stable independent of method or model: knee caused by light primaries positions of knee vary with primary elemental group no (interaction) model can describe the data consistently KASCADE collaboration, Astroparticle Physics 24 (2005) 1-25, astro-ph/0505413 ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

= KArlsruhe Shower Core and Array DEtector + Grande KASCADE-Grande = KArlsruhe Shower Core and Array DEtector + Grande and LOPES Measurements of air showers in the energy range E0 = 100 TeV - 1 EeV ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Detected EAS component The experimental set-up Detector Detected EAS component Sensitive area (m2) Grande Charged particles 37x10 Piccolo 8x10 KASCADE array e/g Electrons, g 490 KASCADE array m Muons (Emth=230 MeV) 622 MTD Muons (Tracking) (Emth=800 MeV) 3x128 MWPCs/LSTs (Emth=2.4 GeV) 3x129 LOPES 30 Radio Trigger Plane (Emth=490 MeV) 208 Calorimeter Hadrons 9x304 The strength of KASCADE-Grande is the multi observables information ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

The KASCADE Array 252 detectors 3.2 m2 each 13 m distant 200 x 200 m2 e/g : liquid, 48 mm m : plastic, 30 mm

The GRANDE Array The detector station The DAQ Peak sensing ADC: 16 plastic scintillator (NE102A) 80x80x4 cm3 Mixers, amplifiers, discriminators HV divider Steel box 4 low gain PMTs 16 high gain PMTs The DAQ Peak sensing ADC: Particle density range: 104 m.i.p./10m2 TDC: 0.8 ns resolution Flash ADC… 37 Stations of plastic scintillators 10 m2 140 m average distance 0.5 km2 total surface ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

The Grande Flash ADC system Flash-ADC system for the Grande array with optical links and a ring buffer system self triggering (no global trigger)  full signal information of the detectors High precision data from Grande array ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE-Grande : Trigger trigger efficiency The trigger system area Trigger rate Number of events E>… Trigger (Grande) 18 clusters 4/7 coincidence  5 Hz 7/7 coincidence  0.5 Hz → sent to all the other components. ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE-Grande : single event measurement lateral distribution of a single event measured by KASCADE-Grande: E021017eV, =33o ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE-Grande : Reconstruction steps 1) core position and angle-of-incidence from Grande array data 2a) shower size (charged particles) 2b) muon number from KASCADE muon detectors 3) electron number from Grande by subtraction of muon content 4) two dimensional size spectrum for the analysis ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Reconstruction accuracy Monte-Carlo studies:  Sufficient reconstruction accuracies for core direction shower size muon number ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Reconstruction : comparison Grande – KASCADE array Event Selection: At least 10 out of 32 pmt inside a KASCADE cluster 7/7 coincindence in Grande DEmax in Grande Station 7 0 m < rKA < 90 m Log NeKA > 6.0 0.4<sGrande<1.4 Grande Station 7 ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Reconstruction : comparison Grande – KASCADE array core position shower size Red = x coord. (East-West) Blue = y coord. (North-South) mean: -0.162 rms: 0.233 ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Reconstruction : comparison Grande – KASCADE array arrival direction 1015 eV <E0< 1016 eV  ~ 1° g ~ 0.8°  < 40° ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE-Grande: lateral distributions Averaged electron lateral distribution ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE-Grande: lateral distributions Averaged muon lateral distribution per reconstructed total muon number ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

KASCADE-Grande : first analysis Unfolding of 2-dimensional shower size spectrum possible  composition Glasstetter et al. – KASCADE-Grande coll., ICRC (2005) Pune, India ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Next steps … reduction of uncertanties on electron and muon number reconstruction: azimuthal asymmetries in inclined showers ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

Conclusions KASCADE-Grande in continuous and stable data taking since 2004 The detector has been studied and understood The performances of the detector look promising First analysis show reasonable preliminary results Lot of physics to explore… ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration

ISCRA 06 – Erice 23/06/06 Fabiana Cossavella for the KASCADE-Grande collaboration