**RSICC CODE PACKAGE CCC‑581**

**1. NAME AND TITLE**

FOTELP-2014: Photons, Electrons and Positrons Transport in 3D by Monte Carlo Techniques.

**AUXILIARY
ROUTINES**

FEPDAT: Generate probabilities distributions of photons, electrons and positrons.

PREGRAF: 2D & 3D imaging data preparation.

VoxView: 3D dose presentation

GVIEW2D & GVIEW3D: Viewing and debugging geometry input files.

**2. CONTRIBUTORS**

Institute of Nuclear Sciences VINCA, Physics Laboratory, Beograd, Serbia, through the NEA Data Bank, Issy-les-Moulineaux, France.

**3. CODING LANGUAGE AND
COMPUTER**

Fortran 77; Linux and Windows PC (C00581MNYCP03).

NEADB package identifier is IAEA1388/05.

**4. NATURE OF PROBLEM
SOLVED**

FOTELP-2014 is a new compact general purpose version of the previous FOTELP-2K6 code designed to simulate the transport of photons, electrons and positrons through three-dimensional material and sources geometry by Monte Carlo techniques, using subroutine package PENGEOM from the PENELOPE code under Linux-based and Windows OS. This new version includes routine ELMAG for electron and positron transport simulation in electric and magnetic fields, RESUME option and routine TIMER for obtaining starting random number and for measuring the time of simulation.

**5. METHOD OF SOLUTION**

Physical rigor is maximized by employing
the best available cross sections and high speed routines for random values
sampling from their distributions, and the most complete physical model for
describing the transport and production of the photon/electron/positron cascade
from 100.0 MeV down to 1.0 keV. FOTELP-2014 is developed for numerical
experiments by Monte Carlo techniques for dosimetry, radiation damage,
radiation therapy and other actual applications of these particles.

For the photon history, the trajectory is generated by
following it from scattering to scattering using corresponding inverse
distribution between collision, types of target, types of collisions, types
of secondaries, their energy and scattering angles. Photon interactions are
coherent scattering, incoherent scattering, photoelectric absorption and
pair production. Doppler broadening in Compton scattering are taken.. The
histories of secondary photons include bremsstrahlung and positron-electron
annihilation radiation. The condensed history Monte Carlo method is used for
the electron and positron transport simulation. During a history the particles
lose energy in collisions, and the secondary particles are generated on the step
according to the probabilities for their occurrence. Electron (positron) energy
loss is through inelastic electron-electron (e-, e-) and positron-electron
(e+, e-) collisions and bremsstrahlung generation. The fluctuation of energy
loss (straggling) is included according to the Landau's or Blunk-Westphal
distributions with 9 gaussians. The secondary electrons, which follow history of
particles, include knock-on, pair production, Compton and photoelectric
electrons. The secondary positrons, which follow pair production, are included,
too. With atomic data, the electron and positron Monte Carlo simulation is
broadened to treat atomic ion relaxation after photo-effect and impact ionization.
Flexibility of the codes permits them to be tailored to specific applications
and allows the capabilities of the codes to be extended to more complex
applications, especially in radiotherapy in voxelized geometry using CT data.
http://www.vin.bg.ac.yu/~rasa/hopa.htm.

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**6. RESTRICTIONS OR
LIMITATIONS**

The present version of FOTELP-2014 code can handle complex quadric geometries with up to surfaces and 5,000 bodies as defined in PENELOPE code.

**7. TYPICAL RUNNING TIME**

The running time largely depends on the
number of histories to be simulated, the kind of initial and cut-off energies
of particles, and the considered geometry. The adopted parameters (energy
cut-offs, geometry zones, etc.) also have an influence on the computing time.

For the cross-section generating, probabilities and inverse
distributions calculation by FEPDAT code, on a Pentium IV with 1.67 MHz and 512
MB RAM, execution time is about five seconds for one material. For example, a
pencil beam depth-dose distribution of 20 MeV electrons incident on a water
phantom by simulation of 100,000 histories can be obtained with a running time
of about 6 minutes on the same computer.

**8. COMPUTER HARDWARE
REQUIREMENTS**

FOTELP is operable on Windows based personal computers and has been run under Linux.

**9. COMPUTER SOFTWARE
REQUIREMENTS**

The FOTELP codes are written in double precision Fortran. Current versions are complete revisions of previous versions. Compaq Visual Fortran 6.5 was used to create the developers’ Windows executables, which are included in the package. Alternately, the gnu g77/gfortran compilers can be used. FOTELP has also been run with the Linux GNU 4.6.1 and Intel 11.1 compilers.

**10. REFERENCES**

**a)
Included in documentation:**

Radovan D. Ilic, FOTELP-2014 - Photons, Electrons and Positrons Monte Carlo Transport Simulation - User's manual, (September 2014).

**b)
Background information:**

R. D. Ilic, “Numerical Experiments with Photons, Electrons and Positrons by Monte Carlo Techniques,” VINCA Report 1609 (1996).

R. D. Ilic, “Computational Simulation of Electron Penetration Through Material by Monte Carlo Techniques: In 100 Years Since Discovery of Electron,” Vol. 6, Serbian Academy of Sciences and Arts, Beograd (1997).

F.Salvat, J.M. Fernandez-Varea, and J.Sempau, “PENELOPE-2006, A Code System for Monte Carlo Simulation of Electron and Photon Transport ,” Workshop Proceedings Barcelona, Spain, OECD ISBN 92-64-02301-1 (July 2006).

**11. CONTENTS OF CODE
PACKAGE**

Included are the referenced document in 10.a, Fortran 77 sources, Windows executable and test cases transmitted in a Windows ZIP file and Linux based tgz file on a single CD.

**12. DATE OF ABSTRACT**

January 1991, revised November 1997, August 1998, November 2001, September 2007, November 2014

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**KEYWORDS: ** CHARGED
PARTICLES; COMPLEX GEOMETRY; ELECTRON; GAMMA- RAY; MONTE CARLO; POSITRON;
MICROCOMPUTER