CORSIKA: Extensive Air Shower Simulation · Stefan Klepser, DESY Zeuthen: CORSIKA 22/25 LPM-Effect...

CORSIKA:Extensive Air Shower Simulation

Stefan Klepser

DESY Zeuthen,Humboldt-Universität zu Berlin

dec 2006

Stefan Klepser, DESY Zeuthen: CORSIKA 2/25

Outline

• CORSIKA basics– introduction– work flow– the code– steering a simulation

• Interaction Models

• CORSIKA in I3

• Special Effects ۻ– curved & upward option– LPM-Effect– ν-induced Showers


Extensive Air Shower Basics

Energy flow:


CORSIKA Task Flow


The Corsika Code...

All code except interaction models & root output is in 1 fortran file corsika.F:

– 2 MB– 61882 lines– 11444 comment lines– 54 functions– 210 subroutines

234 lines / substructure


Simulation: Features

• Input Features:

– Primary Particle Parameters:• Type: γ, p, He, O, Fe, μ, ν...• Energy: single or spectrum• Direction: single or area

– Surrounding Parameters:• Atmosphere• Earth‘s Magnetic Field• Detection height (multiples

possible)

– Simulation Parameters:• Interaction models• Thinning• Energy Thresholds• Curved Atmosphere Option• Upward Option• LPM, Preshower• Neutrino, Cherenkov Tracking

•

Stee

ring

file

optio

ns

Com

pilationoptions

Output Features:

– Secondary Particle Information:• Type: γ, p, He, O, Fe, μ, ...• Energy• Direction• Position• Time

– Longitudinal & Lateral Distributions:• Energy• Particle Number

– Statistical Collision Information• Energies• Number of Secondaries• Multiplicity

– Specials• Neutrinos• Cherenkov-Light• Fluorescence Light


The Input File

run corsika

~ % cd $CORSIKA/run~ % corsika6502Linux_SIBYLL_

to get

DAT000001 (binary) or

on command line:

# yes, neccessaryfluka < input.inp > output.out

DAT000001.root


Sketches of different showers...iron1014 eV

proton1014 eV

photon1014 eV

red = electrons, positrons, gammasgreen = muonsblue = hadrons

Energy cuts:0.1 MeV for e+-, gammas0.1 GeV for muons, hadrons


Sketches of single components –proton shower


Sketches of single components –photon shower


Interaction models


Electromagnetic Interactions: EGS4

• ‚EGS‘ = Electron Gamma Shower Code• ‚4‘ = 4-dimensional simulation• ALL known e+- and γ interactions are included:

– bremsstrahlung– ionisation– d-electrons– Bhabha & Moeller scattering– multiple scattering– annihilation– e+e- pair production– Compton effect– photo effect– Rayleigh scattering– Extended by the LPM-Effect (relevant in the atmosphere > 1018eV)

→ NO PROBLEM HERE!


Hadronic Interactions

Energy ranges:

• resonance range

• intermediate range

• high-energy range

default„high“/„low“ energy

transition


Recommended LE Models:

• FLUKA+ works best and fastest+ always updated due to commercial motivation (NASA, ...)- non-open source → non-transparent

• UrQMD (M. Bleicher et al.)+ real space-time-Simulation+ frequently enhanced- slower

Note: GHEISHA is not updated anymore!It should not be used any longer!


Recommended HE Models:

• QGSJET-II+ highly sophisticated Pomeron-Pomeron coupling+ fits the data best- slow

• SIBYLL+ - different principle+ comparable performance+ faster


Standard settings in I3 muon simulation(nov 2006)

• adopted from dCORSIKA (D. Chirkin):– LE interactions: GHEISHA– HE interactions: QGSJet01.c

→ WHY?


CORSIKA in I3

• simulation doxygen:http://software.icecube.wisc.edu/SIMULATION/

• production homepage:http://icecube.wisc.edu/simulation/

http://software.icecube.wisc.edu/SIMULATION/

http://icecube.wisc.edu/simulation/


InIce CORSIKA in I3

• Module Flow:

I3Muxer → I3GeneratorUCR → I3PropagatorMMC → ...

readsin files

generatedw

ithstandalone

dCO

RSIKA

and propagatesthem

throughthe

planet

(byD

.Chirkin)

wrapper for the

javaprogram

mm

c,

propagatesm

uonsthrough

thedetector

(byD

.Chirkin)


IceTop CORSIKA in I3

• Module Flow:

I3Muxer → I3CorsikaXX → I3ArrayShowerTracer → I3Romeo...

readsin plain

CO

RSIKA files

and putsthe

particlesin the

frame

(byP. N

ießen/ A. O

livas)

calculatesthe

tank signal for eachparticle

bythe

intersect of theparticle

trackw

iththe

tank

(byP. N

ießen)


Special Effects

• Curved & Upward option

• LPM-Effect

• Neutrino-Induced Showers


Curved & Upward optionsfor inclined showers (e.g. neutrino showers)

h

standard curved upward


LPM-Effect

• ‚LPM‘ = Landau-Pomeranchuk-Migdal• effect on high energy gammas > 1018 eV• „The multiple Coulomb scattering angle exceeds

the [bremsstrahlung] emission cone, so theradiation intensity diminishes“

• That means: bremsstrahlung and pair productiondecreases with higher energy or denser air

→ high energy gamma showers get even deeper in the atmosphere


Confusing HE showers...

UHE p-shower~ HE γ-shower!

→ some UHE Events couldhave beenphotons!

LPM

Preshower


Neutrino-Induced Showers

• CORSIKA + HERWIG (O. Pisanti et al.) = ν-induced shower• Mostly horizontally possible (ν + air, mountain) → curved &

upward option!• Different signatures:

νe νe

N N* → shower

νe

N N* → shower

e→ shower

νμ

N N* → shower

μ→ NO shower

ντ

N N* → shower

τ→ decay → shower

doublebang


Summary

• The talk was great• Everything is clear


Resonance Range

All kinds of occuring resonances, well-measured in experiments, are taken into account:

PDG


Intermediate Range

QCD String fragmentation processes:i) inelastic, with gluon radiation ii) elastic, diffraction dissociation


High-Energy Range

• Hard Physics (high pt = „easy“): QCD → Minijet Production, ...

• Soft Physics (low pt = „difficult“): Gribov-Regge-Theory= Treating Parton Cascades as Quasi-Particles

→ POMERON (named after Isaak Yakovlevich Pomeranchuk)

= =


QGSJET-II

(Sergej Ostapchenko)

Semi-hard processes:

CORSIKA: Extensive Air Shower Simulation · Stefan Klepser, DESY Zeuthen: CORSIKA 22/25 LPM-Effect...

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