TIERRAS: an AIRES package to simulate high energy cosmic ray showers underground and

underwater

Matías Tueros

Instituto de Física La Plata – Universidad Nacional de La Plata XLIVth Rencontres du Moriond

La Thuile , Italy – February 1-8 , 2009

AIRES: Extended Air Shower Simulator Used by several collaborations on the Cosmic

Ray community for the last 10 years. Fast, stable, portable and with a small output,

it is ideal for applications that require a huge amount of simulations to improve statistics.

Sybill, QGSJET and QGSJET-II models for high energy hadronic interactions. EPOS is to be added on the next release. MOCCA extended low energy interactions model.

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

TIERRAS: Original Aim & Scope

Continue cosmic ray shower simulations 3m underground (540 g/cm-2) to calculate muon lateral distributions (for AMIGA muon counters)

Use the several thousands AIRES showers already simulated up to ground level.

Use only one simulation software: same physics, same output, same interface with the detector simulation at gound level.

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Module DescriptionTIERRAS is currently implemeted as several AIRES

Special Primary modules

Modified “Atmospheres” for propagation: Soil, Standard Rock, Standard Sea Water and Ice

Use the AIRES propagation routines/physics butModified LPM Effect RoutinesModified Dielectric Suppression RoutinesCaveat: AIRES Misses Muon induced spallation!

TIERRAS underestimates Muon Energy deposit above 2 TeV (Not a problem for AMIGA as on a 10EeV shower, all muons outside of the core are below 500 GeV at ground level)

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Muon Energy Loss

TIERRAS simulation

Usual parametrizations

Muon Flux

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

• MACRO experiment• TIERRAS

(of muon at ground)

Sample Results: AMIGA Depth

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

AMIGA (Auger Muons and Infill for the Ground at Array)

Is an upgrade to the Auger Observatory consisting of

A 27.5 km2 infill of the array, to take the detection threshold of the observatory down to 1x1017 eV.

30 m2 muon counters burried 3m underground to determine the muon content of the showers for mass composition studies.

AIRES + UndergroundShower + AbovegroundShower

1 EeV Vertical Shower, 10-6 thinning, 3m of soil

Muon Lateral DistributionUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Muon/Electron ratioUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Number of GammasUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

AIRESTIERRASUndergroundShower

TIERRASAbovegroundShower

Regain continuity

Ground level

Simulation End(upgoing particles that would have been producedare missing)

Energy of GammasUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Total Energy Mean Energy

Number of GammasUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Proton 1 EeV Iron

Number of MuonsUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Iron1 EeV Proton

Mean Muon EnergyUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Proton 1 EeV Iron

•Start an upgoing shower

•Continue an Airshower Underground

•Continue an Underground Shower on air

•TIERRAS code

•Start an upgoing or downgoing neutrino or exotic shower

•AIRES 2.8.4 code

TIERRAS: Evolving Aim & Scope

Fast particle propagation through dense homogeneous medium.

Applications for shallow (< 3 k.w.e) underground, underwater and underice sites for detector design, detector simulation input, detector calibration and results analysis.

Upgoing and skimming neutrino or exotic particles induced hadronic and electromagnetic showers.

Earth and moon albedo simulations.

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Sample Result: Antares Depth

Energy spectrum of 2TeV muons and all its secondaries propagated through 3 km of sea water, without thinning. Only 2 seconds per muon on my 2Ghz celeron, 7 years old Laptop!

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

Comparison data from V. A. Kudryavtsev, arXiv:0810.4635v1 25 Oct 2008

Sample Result: LPM on e- from e

LPM effect and Dielectric suppression are very important on standard rock above 77 TeV!

Idea from S. Klein, arXiv:0412546v1 21 Dec 2004

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

100s m!

Outlook: a new simulation tool

A beta release version is available upon request for evaluation and testing

Include hard muonic processes and neutrino propagation for very deep simulations is possible, and might be done if sufficient interest from users arises.

Still necessary to validate physics results for Neutrons, Pions and other particles, but looking good.

Independent tests and comparisons with other codes are most welcome!

Underground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

This is not the end, my friend

Electrons to Muons ratioUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Iron1 EeV Proton

Total Number of ParticlesUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Proton 1 EeV Iron

Number of ElectronsUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Proton 1 EeV Iron

Number of NeutronsUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Proton 1 EeV Iron

Number of PionsUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar

1 EeV Proton 1 EeV Iron

Electron Lateral DistributionUnderground Shower Simulations – MJ Tueros tueros@fisica.unlp.edu.ar