Tools for data analysis and MC simulations in exotic nuclear experiments. SIMONE project.

R.S. Slepnev1, V. Chudoba1,2, P. Papka3, P.G. Sharov1, B. Hnatio4, S. Baraeva1, P. Jaluvkova1,2, A.G. Knyazev1

http://aculina.jinr.ru/simone.htm

1 -- Joint Institute for Nuclear Research (JINR), Dubna, Russia 2 -- Institute of Physics, University of Silesia in Opava, Opava, Czech Republic 3 -- Stellenbosch University, Stellenbosch, Western Cape, South Africa 4 -- University of science and tehcnology, Krakov, Poland

Physics of Exotic Nuclei

light nuclei (A<50)exotic structure, rare decay modestypical RIB's energies < 100 MeV/Aa few detector types to disposal

Motivation

There are many various experiments performed, but most of them are based on the same pattern. It means that you have some beam, fixed target and you need to detect reaction and decays products by some complex detector arrangement which subsequently result in sophisticated data analysis.Available tools designated for our field are either too specialized (such as SRIM, LISE++) or provide fundamental methods only and are intended for further developments of specific applications.Of course, you can develop your own software solution for each experiment, but much more efficient is to use some general-purpose tool that can be easily adopted by the user without necessarily modifying the source.We can find many common features of our experimental studies and both, the planning of an experiment and data processing consist of specific steps which are often standard repeated procedures. For example description of particles and their kinematics, detectors, particle tracking and so onmany tasks can be generalized (simulations, some auxiliary methods for data analysisThe main motivation of the SIMONE project is to save human power and time, and standardize the common procedures to reduce the possibility of bias and errors inherent to computer programming.

based on ROOT Data Analysis Frameworkoptional use of alternative methods based on GEANT4, SRIM, ...libraries usable in ROOT CINTarchitecture is reflecting real course of actionsas general as possibleno need for programming for plenty of tasks

General scheme

all essential actions can be fully formalized and automatic user input

theoretical inputexperimental setup description

SIMONE providesprimary event generationdetectors and materials handlingparticle trackingTTree's on output

simulated data of the same structure as experimental

General scheme: Simulations

data analysisunique for each experimental setupoften plagued with unforeseen situations

process of data analysis is identical for both experimental and simulated data

General scheme: Experimental branch

Functionality: Kinematic calculator

2 cornerstones:

lab [degrees]

Ela

b [

MeV

/A]

p(6Li,n)6Be6Be 3-body decay

p(18Ne,d)17Ne17Ne 3-body decay

Calculation of kinematics can be solved either analytically or using MC method. However, the employment of the latter option is more convenient when one deals with multiparameter tasks. MC provides sufficient results and is much more efficient with respect to both difficulty and time requirements.The kinematical calculator itself consists of two major components: class serving for description of arbitrary particle and class modelling nuclear reaction. Class particle provide a set of methods to treat any particle properties, such as kinematical characteristics, atomic mass, charge and so on. Particles may be collected in class Reaction which is intended to manage particles and relativistic kinematical relations between them. Class Reaction distinguishes particles on input and output of the reaction and amongst others provide methods to transform particles into different coordinate systems, methods for generation of binary reactions, 2- and 3-body decays with uniform distribution in space volume are provided. We provide also interface for input of whatever external distributions.

The kinematic methods can be used either on stage of simulation or can be employed for particles properties reconstruction during the experimental data analysis.

concept of parameterized detector classeswhole detector is represented by one entitydetector objects serve as data containersbuild geometry by assigning dimensions, materials, and position together with orientation in spacedetector setup visualisation

Functionality: Geometry

some of the most commondetectors implemented

Functionality: Tracking

E [MeV]

ΔE

[M

eV]

All SIMONE elements of virtual setup possess methods to handle particle passing through it. When a particle enters detector, the interaction of the radiation with the detectors materials are taken into consideration and the momentum of the particle is altered.

We may use two alternative algorithms for tracking and energy losses. They are either ROOT TGeo + various E-losses methods or optionally some external GENAT4 routines.

Currently, only electromagnetic ionization of material by particle passing through is taken into account because it is major source of energy loss in the typical range of low energy nuclear physics.Afterwards, energy deposits are written into detector objects.

too complex for just “click and wait” approachcurrently under development

Functionality: Tools for analysis

common steps are found and standardiseddetector calibrationsauxiliary functions for particle identificationRIB's diagnostics, beam projection on arbitrary planeascertainment of hits in detectorsparticle trajectory reconstruction from trace in telescopeparticle energy reconstruction and handling with dead layers

channelschannels

E [MeV]E [MeV]

ΔE

[M

eV]

Functionality: Control and handling

In order to make the SIMONE package as user friendly as possible and to ensure high level of generality, two different ways of object construction for the most important classes are given. The classical option is to create an object and then adjust its properties using standard Setter methods. A more convenient way is to set all parameters at once using externally stored configuration files which containes information on objects in a structured but easy editable and human readable format.

The main advantages of these config files is that they provide intuitive interface between our libraries and external applications, especially for GUI. GUI was designed to help with setting up entire environment for simulation in a transparent and easy way. The introducing of GUI is a major step towards user friendliness. It also helps to have all parameters visible and editable in one place.

SIMONE is intended for the low-energy nuclear physics communitydevelopment of special tools started in an international collaborationmany tasks isolated and routinizedearly version released

Summary

FLNR JINR

iThemba LABS

AGH CracowSilesianUniversity

Plans for future

more development and validationdiversification of calculation methodshandling of ion opticstesting on multiple platforms

Thank you for attention