CORTÉS GIRALDO , Miguel Antonio

El objetivo general de este proyecto es abrir nuevas líneas de investigación en el Departamento de Física Atómica, Molecular y Nuclear de la Universidad de Sevilla, relacionadas con el estudio del transporte de radiación a través de la materia mediante ... simulaciones Monte Carlo. En esta memoria, se presentan las aplicaciones desarrolladas...

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The specific advantages of ion beams for application in tumor therapy are attributed to their different macroscopic and microscopic energy deposition pattern as compared to conventional photon radiation. On the macroscopic scale, the dose profile with a Bragg peak at the highest depths and small lateral scattering allow a better conformation of...

The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at...

The Monte Carlo simulation of the head of a Siemens Primus Linac used at Virgen Macarena Hospital (Sevilla, Spain) has been performed using the code GEANT4 [1-2], version 9.2. In this work, the main features of the application built by our group are presented. They are mainly focused in the optimization of the performance of the simulation. The...

At the n\_TOF experiment at CERN a dedicated single-crystal chemical vapor deposition (sCVD) Diamond Mosaic-Detector has been developed for (n,alpha) cross-section measurements. The detector, characterized by an excellent time and energy resolution, consists of an array of 9 sCVD diamond diodes. The detector has been characterized and a...

Purpose: This work introduces the concept of segment-averaged linear energy transfer (LET) as a new approach to average distributions of LET of proton beams based on a revisiting of microdosimetry theory. The concept of segment-averaged LET is then used to generate an analytical model from Monte Carlo simulations data to perform fast and...

The spatial distribution of energy deposition events is an essential aspect in the determination of the radiobiological effects of ionizing radiation at the cellular level. Microdosimetry provides a theoretical framework for the description of these events, and has been used in several studies to address problems such as the characterization of...

A translation of the penelope physics subroutines to C++, designed as an extension of the Geant4 toolkit, is presented. The Fortran code system penelope performs Monte Carlo simulation of coupled electron-photon transport in arbitrary materials for a wide energy range, nominally from 50 eV up to 1 GeV. Penelope implements the most reliable...

Background: The photon strength functions (PSFs) and nuclear level density (NLD) are key ingredients for calculation of the photon interaction with nuclei, in particular the reaction cross sections. These cross sections are important especially in nuclear astrophysics and in the development of advanced nuclear technologies. Purpose: The role...

Purpose: To introduce a new algorithm—MicroCalc—for dose calculation by modeling microdosimetric energy depositions and the spectral fluence at each point of a particle beam. Proton beams are considered as a particular case of the general methodology. By comparing the results obtained against Monte Carlo computations, we aim to validate the...

Biological damage induced by ionizing radiation plays a major role in many application fields as radiotherapy and microdosimetry. Geant4-DNA Monte Carlo track-structure code has the capability to simulate the passage of radiation through liquid water, containing physical, physicochemical and chemical processes that lead the early DNA damage....

There is interest in modeling the atmosphere in the South Atlantic Magnetic Anomaly in order to obtain information about the cosmic-ray induced neutron spectrum and angular distribution as functions of altitude. In this work we use the Monte Carlo codes MCNPX and Geant4 to determine the cosmic-ray-induced neutron flux in the atmosphere produced...

Purpose: To study the agreement between proton microdosimetric distributions measured with a silicon-based cylindrical microdosimeter and a previously published analytical microdosimetric model based on Geant4-DNA in-water Monte Carlo simulations for low energy proton beams. Methods and material: Distributions for lineal energy (y) are measured...

Neutron-induced reactions are studied at the neutron time-of-flight facility n-TOF at CERN. The facility uses 6∼ns wide pulses of 20 GeV/c protons impinging on a lead spallation target. The large neutron energy range and the high instantaneous neutron flux combined with high resolution are among the key characteristics of the facility. After a...

Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD) has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross...

The neutron capture cross section of 58Ni was measured at the neutron time of flight facility n_TOF at CERN, from 27 meV to 400 keV neutron energy. Special care has been taken to identify all the possible sources of background, with the so-called neutron background obtained for the first time using high-precision GEANT4 simulations. The energy...