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

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

Status and first results of the KASCADE-Grande experiment


Outline

1. Motivation for KASCADE-Grande

2. Experimental set-up

3. Reconstruction of EAS with KASCADE-Grande

4. First Analysis


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


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’s results:

KASCADE

KASCADE collaboration, Astroparticle Physics 24 (2005) 1-25, astro-ph/0505413


Measurements of air showers in the energy range E0 = 100 TeV - 1 EeV

KASCADE-Grande= KArlsruhe Shower Core and Array DEtector +

Grandeand LOPES


DetectorDetector Detected EAS Detected EAS componentcomponent

Sensitive area Sensitive area (m2)(m2)

GrandeGrande Charged particlesCharged particles 37x1037x10

PiccoloPiccolo Charged particlesCharged particles 8x108x10

KASCADE array KASCADE array e/e/

Electrons, Electrons, 490490

KASCADE array KASCADE array MuonsMuons

(E(Ethth=230 MeV)=230 MeV)

622622

MTDMTD Muons (Tracking) Muons (Tracking) (E(Ethth=800 MeV)=800 MeV)

3x1283x128

MWPCs/LSTsMWPCs/LSTs Muons Muons

(E(Ethth=2.4 GeV)=2.4 GeV)

3x1293x129

LOPES 30LOPES 30 RadioRadio

Trigger Plane Muons

(Eth=490 MeV)

208

Calorimeter Hadrons 9x304

The experimental set-up

The strength of KASCADE-Grande is the multi observables information

The KASCADE Array

• 252 detectors• 3.2 m2 each• 13 m distant• 200 x 200 m2 • e/ : liquid, 48 mm• : plastic, 30 mm


The GRANDE Array

Steel box

16 high gain PMTs

16 plastic scintillator (NE102A) 80x80x4 cm3

4 low gain PMTs

The detector station

The DAQ

HV divider

Mixers, amplifiers, discriminators

37 Stations of plastic scintillators 10 m2

140 m average distance0.5 km2 total surface

Peak sensing ADC:Particle density range: 104 m.i.p./10m2

TDC: 0.8 ns resolutionFlash ADC…


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


The trigger systemareaTrigger rateNumber of events E>…

KASCADE-Grande : Triggertrigger efficiency

Trigger (Grande) 18 clusters 4/7 coincidence 5 Hz 7/7 coincidence 0.5 Hz → sent to all the other components.


KASCADE-Grande : single event measurementlateral distribution of a single event measured by KASCADE-Grande: E021017eV, =33o


KASCADE-Grande : Reconstruction steps

1) core position and angle-of-incidence from Grande array data

2a) shower size (charged particles) from Grande array data

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


Monte-Carlo studies:Sufficient reconstruction accuracies for -core-direction-shower size-muon number

Reconstruction accuracy


Grande Station 7

Event Selection:

At least 10 out of 32 pmt

inside a KASCADE cluster

7/7 coincindence in Grande

Emax in Grande Station 7

0 m < rKA < 90 m

Log NeKA > 6.0

0.4<sGrande<1.4

Reconstruction : comparison Grande – KASCADE array


mean: -0.162rms: 0.233

Reconstruction : comparison Grande – KASCADE arraycore position shower size

Red = x coord.(East-West)

Blue = y coord.(North-South)


arrival direction

1015 eV <E0< 1016 eV

~ 1°

g ~ 0.8°

Reconstruction : comparison Grande – KASCADE array

< 40°


KASCADE-Grande: lateral distributionsAveraged electron lateral distribution


Averaged muon lateral distribution per reconstructed total muon number

KASCADE-Grande: lateral distributions


KASCADE-Grande : first analysis

Unfolding of 2-dimensional shower size spectrum possible composition

Glasstetter et al. – KASCADE-Grande coll., ICRC (2005) Pune, India


reduction of uncertanties on electron and muon number reconstruction: azimuthal asymmetries in inclined showers

Next steps …


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…


Documents

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