Computer Programs
NEA-1525 PENELOPE2018.
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NEA-1525 PENELOPE2018.

PENELOPE2018, A Code System for Monte-Carlo Simulation of Electron and Photon Transport

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1. NAME OR DESIGNATION OF PROGRAM

PENELOPE2018

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2. COMPUTERS

To submit a request, click below on the link of the version you wish to order. Rules for end-users are available here.

Program name Package id Status Status date
PENELOPE2018 NEA-1525/23 Tested 31-MAR-2020

Machines used:

Package ID Orig. computer Test computer
NEA-1525/23 Linux-based PC,PC Windows,UNIX W.S. Linux-based PC,PC Windows
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3. DESCRIPTION OF PROGRAM OR FUNCTION

PENELOPE performs Monte Carlo simulation of coupled electron-photon transport in arbitrary materials and complex quadric geometries. A mixed procedure is used for the simulation of electron and positron interactions (elastic scattering, inelastic scattering and bremsstrahlung emission) in which 'hard' events (i.e. those with deflection angle and/or energy loss larger than pre-selected cut-offs) are simulated in a detailed way, while 'soft' interactions are calculated from multiple scattering approaches. Photon interactions (Rayleigh scattering, Compton scattering, photoelectric effect and electron-positron pair production) and positron annihilation are simulated in a detailed way, event by event.

 

Improvements in the 2018 version compared to version 2014.

  1. The angular distributions of bremsstrahlung photons are now determined from an increased set of 910 shape functions, which were calculated with the program of Poskus (2018).

  2. The angular distribution of photoelectrons now includes the effect of photon polarisation.

  3. As in previous versions of the code, the photoabsorption database has been calculated with the Pratt normalisation screening correction. Although this correction seems to improve agreement with dose measurements, its consistency with the theory underlying the calculations of the photoeffect is debatable. An alternative database calculated without that correction is included in the distribution package.

  4. The program 'penmain.f' now can simulate radioactive sources on the basis of evaluated nuclear data from the NUCLEIDE database.

  5. The simulation of atomic relaxation now includes the effect of multiple vacancies in the final and intermediate subshells. The subroutine RELAX has been recoded.

  6. The initialisation of the RITA algorithm for sampling elastic scattering of electrons and positrons from the ELSEPA differential cross section has been modified by using a denser uniform grid of angles. This avoids unphysical features in the angular distribution at large angles.

  7. A bug in the source code 'pengeom.f' that affected trajectories in a vacuum between two material bodies has been corrected. Specifically, after a flight in vacuum, an undershot in the entrance to the material body placed the particle in the vacuum, this caused the main program to incorrectly assume that the particle had left the enclosure.

  8. The program PENMAIN now permits generating files with a number of particle histories, which can be visualised with gnuplot.

 

NB: The formats of the input files of the present 2018 version of PENELOPE are NOT compatible with those of version 2014; material data files need to be generated with the 2018 version of the 'material.f' program (or with the program 'tables.f').

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4. METHODS

The Monte Carlo method is used. A sufficiently large number of particle histories is simulated, and relevant quantities are obtained as averages.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The program can track electrons, positrons, and photons with kinetic energies in the range from 50 eV to 1 GeV. However, the adopted interaction models are not expected to be accurate for energies below about 1 keV. X rays and Auger electrons originating from vacancies in the outer (O, P …) subshells of heavy elements are not followed. Photo-nuclear reactions are disregarded.

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6. TYPICAL RUNNING TIME

The running time largely depends on the number of histories to be simulated, the kind of incident particle, its initial energy and the considered geometry. The adopted simulation parameters (energy cut-offs, etc.) also influence the computing time. As an example, a broad-beam depth-dose distribution of 10 MeV electrons incident on a water phantom, resulting from 100.000 simulated histories, is obtained with a running time of some 180 s on an Intel Core i7/8550U CPU at 1.99 GHz with 16 GB RAM.

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7. UNUSUAL FEATURES OF THE PROGRAM

The mixed simulation algorithm for electrons and positrons implemented in PENELOPE reproduces the actual transport process to a high degree of accuracy and is very stable even at high energies. This is partly due to the use of a sophisticated transport mechanics model for charged particles based on the so-called random hinge method. Other differentiating features of the simulation are a consistent description of angular deflections in inelastic collisions and of energy-loss straggling in soft stopping events. Binding effects and Doppler broadening in Compton scattering are also taken into account.

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8. RELATED OR AUXILIARY PROGRAMS

graphic user interfaces:

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9. STATUS
Package ID Status date Status
NEA-1525/23 31-MAR-2020 Tested at NEADB
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10. REFERENCES
  • J. Sempau, E. Acosta, J. Baro, J.M. Fernandez-Varea and F.Salvat:
    An algorithm for Monte Carlo simulation of the coupled electron-photon transport. Nuclear Instruments and Methods B 132 (1997) 377-390.

  • J. Sempau, J.M. Fernandez-Varea, E. Acosta and F. Salvat:
    Experimental benchmarks of the Monte Carlo code PENELOPE. Nuclear Instruments and Methods B 207 (2003) 107-123.

NEA-1525/23, included references:
- Francesc Salvat:
PENELOPE-2018 - A Code System for Monte Carlo Simulation of Electron and Photon
Transport - Workshop Proceedings Barcelona, Spain 28 January - 1 February 2019
(NEA/MBDAV/R(2019)1 - ISSN 2707-2894 - July 2019)
- Tutorial for PENELOPE (version 2018)
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11. HARDWARE REQUIREMENTS

There are no specific requirements for the PENELOPE kernel.

 

This version was tested at the Data Bank on:

WINDOWS:

  • Computer: Dell Precision M6800 with Intel(R) Core (TM) i7-4800MQ CPU at 2.70 GHz x 8, RAM: 16.0 GB

  • Operating system: Windows 10

  • Compiler: gfortran 6.3.0

LINUX:

  • Computer: Dell Precision M6800 with Intel(R) Core (TM) i7-4800MQ CPU at 2.70 GHz x 8, RAM: 16.0 GB

  • Operating system: Ubuntu 18.04

  • Compiler: gfortran v7.4.0

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12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NEA-1525/23 FORTRAN-90
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13. SOFTWARE REQUIREMENTS

Any operating system supporting a Fortran 90 compiler.

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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

None.

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15. NAME AND ESTABLISHMENT OF AUTHORS

Francesc Salvat and Jose Maria Fernandez-Varea

Facultat de Fisica (FQA), Universitat de Barcelona

Diagonal 645, 08028 Barcelona, Catalonia, Spain

 

Josep Sempau

ETSEIB, Universitat Politecnica de Catalunya

Diagonal 647, 08028 Barcelona, Spain

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16. MATERIAL AVAILABLE
NEA-1525/23
readme.txt      Readme file
\fsource\       FORTRAN90 source files of the PENELOPE code system
\mains\         pencyl and penmain modules of PENELOPE
\emfields\      Software package for simulating radiation transport in static
electro-magnetic fields
\gview\         Software for quadratic geometry visualisation
\shower\        Software for displaying particle tracks on the screen of the
computer
\tables\        Reads material files and generates tables of interaction data as

functions of energy
\pendbase\      PENELOPE database
\doc\penelope-2018-NEA.pdf Manual of PENELOPE 2018
\doc\tutorial.pdf    Installation procedure and examples
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17. CATEGORIES
  • J. Gamma Heating and Shield Design

Keywords: Monte Carlo method, bremsstrahlung, high-energy reactions, photon transport, positrons.