Extension of charge-state-distribution calculations for ion-solid collisions towards low velocities and many-electron ions

Knowledge of the detailed evolution of the whole charge-state distribution of projectile ions colliding with targets is required in several fields of research such as material science and atomic and nuclear physics but also in accelerator physics, and in particular in regard to the several foreseen large-scale facilities. However, there is a lack of data for collisions in the nonperturbative energy domain and that involve many-electron projectiles. Starting from the etacha model we developed [Rozet, Nucl. Instrum. Methods Phys. Res., Sect. B 107, 67 (1996)10.1016/0168-583X(95)00800-4], we present an extension of its validity domain towards lower velocities and larger distortions. Moreover, the system of rate equations is able to take into account ions with up to 60 orbital states of electrons. The computed data from the different new versions of the etacha code are compared to some test collision systems. The improvements made are clearly illustrated by 28.9MeVu-1Pb56+ ions, and laser-generated carbon ion beams of 0.045 to 0.5MeVu-1, passing through carbon or aluminum targets, respectively. Hence, those new developments can efficiently sustain the experimental programs that are currently in progress on the "next-generation" accelerators or laser facilities.Fil: Lamour, E.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Fainstein, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Prigent, C.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Ramirez, C. A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Rozet, J. P.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Trassinelli, M.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Vernhet, D.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; Franci

Ionization induced by protons on isolated molecules of adenine: theory, modelling and experiment

We here report a comparison between semi-empirical and theoretical predictions in terms of differential and total cross sections for proton-induced ionization of isolated adenine molecules. Whereas the first ones are provided by existing analytical models, the second ones are based on two quantum-mechanical models recently developed within the 1st Born and the continuum distorted wave approximation, respectively. Besides, a large set of experimental data is also reported for comparisons. In all kinematical conditions here investigated, we have observed a very good agreement between theory and experiment whereas strong discrepancieswere reported with the semi-empirical models in particular when doubly-differential cross sections are analysed.Fil: Champion, C.. Universite de Bordeaux; FranciaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Weck, P. F.. University of Nevada Las Vegas. Department of Chemistry and Harry Reid Center for Environmental Studies; Estados UnidosFil: Abdallah, C.. University Saint Joseph. Faculty of Sciences. Department of Physics; LíbanoFil: Francis, Z.. University Saint Joseph. Faculty of Sciences. Department of Physics; Líbano. The Open University. Faculty of Science. Department of Physical Sciences; Reino UnidoFil: Quinto, M. A.. Universite de Bordeaux; FranciaFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Hanssen, Jocelyn. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Iriki, Y.. Kyoto University. Department of Nuclear Engineering; JapónFil: Itoh, A.. Kyoto University. Department of Nuclear Engineering; Japó

Preliminar study of the effects of gamma radiations on human red blood cells

En este estudio se analizaron los parámetros viscoelásticos y de agregación en glóbulos rojos humanos sometidos a los procedimientos habituales de irradiación gamma con fines transfusionales. Las muestras fueron irradiadas a diferentes dosis a fin de determinar los posibles cambios hemorreológicos que pudieran afectar a la salud de los pacientes y su relación con las modificaciones bioquímicas observadas. Los resultados obtenidos muestran alteraciones en el tiempo de agregación, en la viscosidad superficial de membrana y en el tamaño de los agregados eritrocitarios en las muestras irradiadas, sugiriendo que el daño producido por la radiación ionizante afecta a las propiedades físicas de la membrana del glóbulo rojo en diferentes nivelesIn this study, the alterations in viscoelastic and aggregation parameters of red blood cells were analyzed for usual gamma irradiation procedures for transfusion purposes. In order to determine possible hemorheological changes that may affect the health of patients and their relationship with the biochemical changes observed, the blood samples were irradiated at different doses. The results show alterations in the erythrocyte aggregation time, in the membrane surface viscosity and in the size of the aggregates in the irradiated samples, suggesting that the damage produced by the ionizing radiation affects the physical properties of red blood cell membrane at different levels.Fil: Estrada, E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Castellini, H.. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Acosta, A.. Centro Regional de Hemoterapia; ArgentinaFil: Di Tullio, L.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: Borraz, J.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: Chinellato, A.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: Tack, I.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: D'Arrigo, M.. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Riquelme, Bibiana Doris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentin

Monte Carlo transport of swift protons and light ions in water: The influence of excitation cross sections, relativistic effects, and Auger electron emission in w-values

International audiencePurposeTo develop a particle transport code to compute w-values and stopping power of swift ions in liquid water and gases of interest for reference dosimetry in hadrontherapy. To analyze the relevance of inelastic and post-collisional processes considered.MethodsThe Monte Carlo code MDM was extended to the case of swift ion impact on liquid water (MDM-Ion). Relativistic corrections in the inelastic cross sections and the post-collisional Auger emission were considered. The effects of introducing different electronic excitation cross sections were also studied.ResultsThe stopping power of swift ions on liquid water, calculated with MDM-Ion, are in excellent agreement with recommended data. The w-values show a strong dependence on the electronic excitation cross sections and on the Auger electron emission. Comparisons with other Monte Carlo codes show the relevance of both the processes considered and of the cross sections employed. W and w-values for swift electron, proton, and carbon ions calculated with the MDM and MDM-Ion codes are in very close agreement with each other and with the 20.8 eV experimental value.ConclusionWe found that w-values in liquid water are independent of ion charge and energy, as assumed in reference dosimetry for hadrontherapy from sparse experimental results for electron and ion impact on gases. Excitation cross sections and Auger emission included in Monte Carlo codes are critical in w-values calculations. The computation of this physical parameter should be used as a benchmark for micro-dosimetry investigations, to assess the reliability of the cross sections employed

6.0 MeV u-1 carbon ion (C6+ and C4+)-induced secondary electron emission from water vapour

Theoretical calculations of the DDCSs were made for C6+ ions using the continuum distorted wave-eikonal initial state model (CDW-EIS) in its straight-line version of the impact parameter approximation, showing general good agreement with experimental data, except in the intermediate- and high-energy region. On the other hand, the single differential cross section (SDCS), which was obtained by integrating the measured DDCSs over the solid angle, showed fairly good agreement with the CDW-EIS in the low-energy region, while a significant discrepancy between the observed SDCS and the Rudd-model scaling can be seen,suggesting that a simple -scaling law (i.e. first Born approximation) is not applicable for bare projectiles such as C6+ ions. The SDCS of C4+ ions was observed to be smaller than that of C6+ ons by 50% in the low-energy region (due to the screening effect of its bound electrons in C4+ ions, which could be explained quantitatively by taking accountFil: Ohsawa, D.. Kyoto University. Radioisotope Research Center; JapónFil: Tawara, H.. National Institute for Fusion Science; JapónFil: Soga, F.. National Institute of Radiological Sciences; JapónFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentin

Track structure of protons and other light ions in liquid water: Applications of the LIonTrack code at the nanometer scale

The LIonTrack (Light Ion Track) Monte Carlo (MC) code for the simulation of H+, He2+, and other light ions in liquid water is presented together with the results of a novel investigation of energy-deposition site properties from single ion tracks. Methods:The continuum distorted-wave formalism with the eikonal initial state approximation (CDW-EIS) is employed to generate the initial energy and angle of the electrons emitted in ionizing collisions of the ions with H2O molecules. The model of Dingfelder et al. [Electron inelastic scattering cross sections in liquid water, Radiat. Phys. Chem. 53, 1-18 (1999); Comparisons of calculations with PARTRAC and NOREC: Transport of electrons in liquid water, Radiat. Res. 169, 584-594 (2008)] is linked to the general-purpose MC code PENELOPE/penEasy to simulate the inelastic interactions of the secondary electrons in liquid water. In this way, the extended PENELOPE/penEasy code may provide an improved description of the 3D distribution of energy deposits (EDs), making it suitable for applications at the micrometer and nanometer scales. Single-ionization cross sections calculated with the ab initio CDW-EIS formalism are compared to available experimental values, some of them reported very recently, and the theoretical electronic stopping powers are benchmarked against those recommended by the ICRU. The authors also analyze distinct aspects of the spatial patterns of EDs, such as the frequency of nearest-neighbor distances for various radiation qualities, and the variation of the mean specific energy imparted in nanoscopic targets located around the track. For 1 MeV/u particles, the C6+ ions generate about 15 times more clusters of six EDs within an ED distance of 3 nm than H+. On average clusters of two to three EDs for 1 MeV/u H+ and clusters of four to five EDs for 1 MeV/u C6+ could be expected for a modeling double strand break distance of 3.4 nm.Fil: Bäckström, Gloria. Uppsala University. Section of Medical Radiation Physics. Department of Radiology, Oncology and Radiation Science; SueciaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Tilly, N.. Uppsala University. Section of Medical Radiation Physics. Department of Radiology, Oncology and Radiation Science; SueciaFil: Ahnesjö, A.. Uppsala University. Section of Medical Radiation Physics. Department of Radiology, Oncology and Radiation Science; SueciaFil: Fernandez Varea, J. M.. Universidad de Barcelona. Facultad de Física; Españ

Cálculo de secciones eficaces de ionización simple de blancos moleculares por impacto de protones

Se calcularon secciones eficaces doblemente diferenciales (SEDD) de ionización simple por impacto de protones sobre blancos de N₂, CO, CH₄ y CO₂ aplicando el modelo CDW-EIS (Continuum Distorted Wave - Eikonal Initial State). Para emplear el formalismo de onda distorsionada en el tratamiento de moléculas, se han realizado dos aproximaciones: una que hace uso de la regla de aditividad de Bragg y otra basada en el método LCAO (Combinación Lineal de Orbitales Atómicos). En el primer caso no se tiene en cuenta el carácter molecular del blanco, ya que la sección eficaz molecular se calcula como la suma de las secciones eficaces correspondientes a cada tipo de átomo interviniente, multiplicadas por el número de éstos en la molécula. Una mejor descripción del blanco se logra calculando la SEDD de cada orbital molecular como una combinación lineal de SEDD atómicas cuyos coeficientes surgen de realizar un análisis poblacional. Las energías de enlace correspondientes a cada orbital molecular se han extraído de espectros experimentales. Se presentan también secciones eficaces totales (SET) de ionización simple de los blancos moleculares antes citados. Todos los resultados obtenidos se comparan con datos experimentalesDouble differential cross sections (SEDD) of single ionization for proton impact on N₂, CO, CH₄ and CO₂ have been calculated applying the CDW-EIS model (Continuum-Distorted-Wave-Eikonal-Initial-State). Two different app roximations were considered to employ the distorted wave formalism in the case of molecular targets: the Bragg's additivity rule and another based on the LCAO (Lineal Combination of Atomic Orbitals) approximation In the first case, the molecular character was not taken into account. The cross section is calculated as the sum of the ones corresponding to each atom constituting the molecule, multiplied by the number of these atoms in the molecule. A better description of the target is obtained approximating the molecular SEDD as a linear combination of atomic SEDD, with coefficients determined from a population analysis of the atomic constituents of the molecule. The binding energies have been extracted from experimental spectra. Total ionisation cross sections are also presented. Results are compared with experimental dataFil: Galassi, Mariel Elisa. Universidad Nacional de Rosario - CONICET. Instituto de Física de Rosario (IFIR). Santa Fe. ArgentinaFil: Fainstein, Pablo Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche (CNEA-CAB). Río Negro. ArgentinaFil: Olivera, Gustavo Hugo. University of Wisconsin-Madison. Medical School. Madison. Estados UnidosFil: Beuve, Michaël. Centre Interdisciplinaire de Recherches Ion-Laser. Caen. FranciaFil: Rivarola, Roberto Daniel. Universidad Nacional de Rosario - CONICET. Instituto de Física de Rosario (IFIR). Santa Fe. Argentin

New insights into the mechanics of erythrocytes: effects of radiation and several drugs of biomedical interest

The study of the erythrocyte morphology, interaction, and dynamics is essential to understand how several pathologies and anomalies can alter microcirculation, disturbing the well-functioning of the organism. The erythrocyte membrane changes in many hematological and vascular diseases can alter blood functions. The blood fluidity is due directly to the viscoelastic properties of the erythrocytes. The erythrocytes aggregates can be excessively resistant to dissociation in pathological conditions. Hence, the development of instruments and methodology for the characterization of erythrocyte viscoelasticity and aggregation continues to be necessary. We have developed and patented the Erythrocyte Rheometer to evaluate the stationary and dynamic viscoelasticity of the erythrocyte. We have designed an Optical Chip Aggregometer to obtain the kinetics parameters of erythrocyte aggregation. We have standardized the analysis of the digital images to study the morphology of erythrocytes and their aggregates. In the last few works, we focused on different in vitro alterations produced by radiation and drug treatments, which could modify the erythrocyte mechanics. Also, we study drugs commonly used in anesthesia and gamma radiation that could alter erythrocyte aggregation and mechanical properties. The new techniques and methodologies developed in our Laboratory to evaluate the erythrocyte mechanics promise to be very helpful in Biomedicine.Fil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina.Fil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Consejo de Investigaciones (CIUNR); Argentina.Fil: Toderi, Martín A. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina.Fil: Batista, M. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Galassi, Mariel Elisa. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina.Fil: Galassi, Mariel Elisa. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura; Argentina.Fil: Castellini, Horacio V. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura; Argentina.Fil: Estrada, Ezequiel. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Estrada, Ezequiel. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura; Argentina.Fil: Alet, Analía I. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Alet, Analía I. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura; Argentina

Water versus DNA: New insights into proton track-structure modelling in radiobiology and radiotherapy

Water is a common surrogate of DNA for modelling the charged particle-induced ionizing processes in living tissue exposed to radiations. The present study aims at scrutinizing the validity of this approximation and then revealing new insights into proton-induced energy transfers by a comparative analysis between water and realistic biological medium. In this context, a self-consistent quantum mechanical modelling of the ionization and electron capture processes is reported within the continuum distorted wave-eikonal initial state framework for both isolated water molecules and DNA components impacted by proton beams. Their respective probability of occurrence - expressed in terms of total cross sections - as well as their energetic signature (potential and kinetic) are assessed in order to clearly emphasize the differences existing between realistic building blocks of living matter and the controverted water-medium surrogate. Consequences in radiobiology and radiotherapy will be discussed in particular in view of treatment planning refinement aiming at better radiotherapy strategies.Fil: Champion, C.. Universite de Bordeaux; Francia. Centre National de la Recherche Scientifique; FranciaFil: Quinto, Michele Arcangelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Monti, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Weck, P. F.. Sandia National Laboratorie; Estados UnidosFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Hanssen, Jocelyn. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentin

Preliminar study of the effects of gamma radiation on human redblood cells

En este estudio se analizaron los parámetros viscoelásticos y de agregación en glóbulos rojos humanos sometidos a los procedimientos habituales de irradiación gamma con fines transfusionales. Las muestras fueron irradiadas a diferentes dosis a fin de determinar los posibles cambios hemorreológicos que pudieran afectar a la salud de los pacientes y su relación con las modificaciones bioquímicas observadas. Los resultados obtenidos muestran alteraciones en el tiempo de agregación, en la viscosidad superficial de membrana y en el tamaño de los agregados eritrocitarios en las muestras irradiadas, sugiriendo que el daño producido por la radiación ionizante afecta a las propiedades físicas de la membrana del glóbulo rojo en diferentes niveles.In this study, the alterations in viscoelastic and aggregation parameters of red blood cells were analyzed for usual gamma irradiation procedures for transfusion purposes. In order to determine possible hemorheological changes that may affect the health of patients and their relationship with the biochemical changes observed, the blood samples were irradiated at different doses. The results show alterations in the erythrocyte aggregation time, in the membrane surface viscosity and in the size of the aggregates in the irradiated samples, suggesting that the damage produced by the ionizing radiation affects the physical properties of red blood cell membrane at different levels.Fil: Estrada, Ezequiel. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina.Fil: Estrada, Ezequiel. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina.Fil: Castellini, Horacio V. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina.Fil: Acosta, Andrea. Centro Regional de Hemoterapia de Santa Fe; Argentina.Fil: Di Tullio, Liliana. Centro Regional de Hemoterapia de Santa Fe; Argentina.Fil: Borraz, Javier. Centro Regional de Hemoterapia de Santa Fe; Argentina.Fil: Chinelatto, Alejandro. Centro Regional de Hemoterapia de Santa Fe; Argentina.Fil: Tack, Ivan, Ivan. Centro Regional de Hemoterapia de Santa Fe; Argentina.Fil: D'Arrigo, Mabel. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Área Química Analítica Clínica; Argentina.Fil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina.Fil: Galassi, Mariel E. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina.Fil: Galassi, Mariel E. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina