Methodology to address radioprotection and safety issues in the IFMIF/EVEDA accelerator prototype

In the IFMIF/EVEDA accelerator prototype, deuterons (with energies up to 9 MeV) interact with the materials of the accelerator components due to beam losses and in the beam dump, where the beam is stopped. The productions of neutrons/photons together with radioactive inventories due to deuteron-induced reactions are some major issues for radioprotection and safety assessment. Here, we will focus on the proposal of a computational approach able to simulate deuteron transport and evaluate deuteron interactions and production of secondary particles with acceptable precision. Current Monte Carlo codes, such as MCNPX or PHITS, when applied for deuteron transport calculation, use built-in semi-analytical models to describe deuteron interactions. These models are found unreliable in predicting neutron and photon generated by low energy deuterons, typically present in the IFMIF/EVEDA prototype accelerator. In this context, a new computational methodological approach is proposed based on the use of an extended version of current MC codes capable to use evaluated deuteron libraries for neutron (and gamma) production. The TALYS nuclear reaction code is found to be an interesting potential candidate to produce the evaluated data for double-differential neutron and photon emission cross sections for incident deuterons in the energy range of interest for IFMIF/EVEDA applications. The recently-released deuteron Talys-based Evaluated Nuclear Data Library, TENDL-2009, is considered a good starting point in the road to achieve deuteron data files of enough quality for deuteron transport problems in EVEDA. Unfortunately, current Monte Carlo transport codes are not able to handle light ion libraries except for protons. To overcome this drawback the MCNPX code has been extended to handle deuteron (also triton, helion and alpha) nuclear data libraries. In this new extended MCNPX version called MCUNED, a new variance reduction technique has also been implemented for the production of secondary particles induced by light ions nuclear reactions, which allow reducing drastically the computing time needed in transport and nuclear response function calculations. Verification of these new capabilities for Monte 2 Carlo simulation of deuteron transport and secondary products generation included in MCUNED is successfully achieved. The existence of the MCUNED code allows us for the first time testing the deuteron crosssection TENDL package by simulation of integral experiments. Some preliminary efforts are addressed to compare existing experimental data on thick target neutron yields for Copper with those computed by the MCUNED code using TENDL cross sections

Deuteron cross section evaluation for safety and radioprotection calculations of IFMIF/EVEDA accelerator prototype

under construction in Japan. Interaction of these deuterons with matter will generate high levels of neutrons and induced activation, whose predicted yields depend strongly on the models used to calculate the different cross sections. A benchmark test was performed to validate these data for deuteron energies up to 20 MeV and to define a reasonable methodology for calculating the cross sections needed for EVEDA. Calculations were performed using the nuclear models included in MCNPX and PHITS, and the dedicated nuclear model code TALYS. Although the results obtained using TALYS (global parameters) or Monte Carlo codes disagree with experimental values, a solution is proposed to compute cross sections that are a good fit to experimental data. A consistent computational procedure is also suggested to improve both transport simulations/prompt dose and activation/residual dose calculations required for EVEDA

Investigation on the potential of improvement in the field of medical applications of ionizing radiation via the future European Metrology Network

Due to constant development in radiodiagnostic and radiotherapy procedures with increasing complexity, a need for high-level coordination of the ionizing radiation metrology community was recognized to better respond to the needs of end users. In order to facilitate knowledge dissemination and improve communication between stakeholders involved in medical applications of ionizing radiation, a Joint Network Project was started in 2020. One of the specific objectives of Work Package 2 of the project 19NET04 MIRA, “Support for a European Metrology Network on the medical use of ionizing radiation” is to support the developing states, ensuring that the planned EMN is inclusive through improvements in the medical use of ionizing radiation [1]. Czech Republic, Romania and Serbia were defined as countries of interest to conduct the survey and collect relevant data from stakeholders in the category of medical staff and professionals, so that the potential for improvement for medical applications of ionizing radiation can be evaluated. For the purpose of data collection, an online questionnaire was prepared and distributed to the stakeholders. The questionnaire was structured in such a way to allow easier collection of information regarding availability of (1) calibration services; (2) documented technical protocols; (3) standard documentation in the establishments for different ionizing radiation applications. Implementation of a Quality assurance (QA) programme was investigated, as well as the consistency in realization of proficiency testing (PT) or audits. The stakeholders were asked if additional workshops or training programmes are needed in their area of expertise. The radiodiagnostic modalities included in the questionnaire were the general radiography, mammography, computed tomography and interventional procedures, while radiotherapy modalities included external beam radiotherapy (teletherapy) and brachytherapy. Although nuclear medicine (therapy and diagnostic) procedures were part of the questionnaire, none of the respondents have capabilities for these applications. Based on the information collected via the online questionnaire, calibration services are available for most of the modalities, except for brachytherapy where traceability is not established. QA and PT are regularly performed in radiotherapy, while it is not the case in radiodiagnostic modalities. Improvement in knowledge transfer is needed for all of the applications investigated. Considering the acquired information, there is a clear need for EMN to support knowledge transfer, communication and technical exchange between the metrology community and the stakeholders involved in the medical applications of ionizing radiation. The forthcoming European Metrology Network will further elaborate the knowledge dissemination and stakeholder dialogue through its stakeholder panels and joint training effortsX JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr

VERIDIC: validation and estimation of radiation skin dose in interventional cardiology

Interventne procedure u radiologiji i kardiologiji povezani su sa visokim dozama za kožu pacijenta i potencijalnim radijacionim povredama kože. Različita metodologije i rešenja razvijene us za procenu maksimalne doze za kožu, čija se svojsvta, uključujuši i tačnost značajno razlikuju. U radu su prokazani ciljevi, metode i preminiran a rešenja projekta VERIDIC usmerenoj na validaciju zaličitih ofline i online softvera za procenu doze za kožu pacijenta u intervenatnoj kardiologiji.In interventional cardiology (IC), patients may be exposed to high doses to the skin resulting in tissue reactions (skin burns) following single or multiple procedures. To address this issue, online and offline software has been developed to estimate the maximum skin dose (MSD) to the patient from IC procedures. However, the capabilities and accuracy of such skin dose calculation (SDC) software to estimate MSD and 2D dose distributions markedly differ among vendors. Hence, this project focuses onthe harmonisation of RDSR (radiation dose structured report) and on the validation of SDC software products in IC, which will optimise radiation protection of patients. The outcome of the project will include the standards for digital dose reporting, development of protocols for acceptance testing and Quality Control (QC)of SDC software and setting of diagnostic reference levels per clinical complexity, assessing thefrequency of high-dose procedures as well as dose reduction strategies based on the multi-centric data collection. This paper focuses on the work performed to investigate performance of solid state dosimeters used in clinical environment.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Development of a new method for the detection of illicit materials based on the active interrogation method and photoneutron spectrometry

The 8th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications; (ANIMMA 2023) , Lucca, Italy, June 12-16 2023International audienceThis work investigates the development of a novel method for the detection of illicit materials based on active photon interrogation associated to photoneutron spectrometry. It is an original attempt to explore the principle of inducing photonuclear reactions on samples to determine the presence of light elements such as nitrogen, oxygen and carbon and therefore to extend the use of active photon interrogation for the detection of conventional explosives, narcotics and chemical weapons

Development of a new method for neutron spectra analysis based on a deep learning algorithm for the detection of illicit materials

International audienceThe global context and the growth in international trade is widely recognized as a boon for the trafficking of illicit materials. In the area of homeland security, the approaches used have failed to provide an up and running technique for non-intrusive on-site inspections. Neutron-induced reactions rely on precise measurement of gamma spectra, which is generally very complex due to high level of background noise. Active photon interrogation methods have also been overlooked but only in the context of actinide detection using photofission reactions (γ,f). This work describes the design of a novel method for the detection of illicit materials based on active photon interrogation associated to photoneutron spectrometry. It is the first attempt to explore the principle of inducing photonuclear reactions on samples to determine the composition of light elements such as nitrogen, oxygen and carbon and therefore to extend the use of active photon interrogation for the detection of conventional explosives, narcotics and chemical weapons. The approach is based on a source of photons produced by electron linear accelerator to induce photonuclear reactions on different materials, on the spectrometry of the photoneutrons created, and on the implementation of a new digital analysis method based on a convolutional neural network for extracting the neutron contribution for each photon energy of the bremsstrahlung spectrum in the total neutron spectra measured. The results of this study suggest that the use of neural networks trained with Monte Carlo simulated spectra can be a digital alternative to the "tagged photon" experimental method. Our study, therefore, provides the foundation of a new way of extracting neutron contributions for discrete photon energy of the continuous bremsstrahlung spectrum

Fricke-Xylenol orange-Gelatin gel characterization with dual wavelength cone-beam optical CT scanner for applications in stereotactic and dynamic radiotherapy

International audiencePurpose: This study is about the development of a new dual wavelength reading method of Fricke-Xylenol orange-Gelatin (FXG) gel dosimeters on the Vista16™ optical Computed Tomography (CT) scanner to perform 3D dose distribution measurements in stereotactic and dynamic radiotherapy treatments.Methods: The dosimetric characteristics of an optimized FXG gel composition and its optical CT readout have been evaluated. A dual wavelength reading method has been developed on the CT scanner at wavelengths 590 nm and 633 nm. Small-field dose profile measurements with FXG gel and microDiamond (PTW) detectors were compared by γ-index analysis (0.5%/0.5mm) to validate this method. Results: This new reading method exhibits linear calibration curves in the 0 - 4 Gy and 2 - 10 Gy dose ranges at 590 nm and 633 nm respectively. The absorbed dose values under 4 Gy, measured at 590 nm, and those above 4 Gy, measured at 633 nm, are combined to plot a complete profile. A γ passing rate of 93.4 % was achieved.Conclusions: The new reading method of FXG gel dosimeters has been successfully implemented on the Vista16™ scanner to span absorbed doses representative of stereotactic and dynamic radiotherapy treatments and enable 3D measurements in tumor volumes and surrounding healthy tissues. Small-field profile measurements validated this reading method as FXG gel dosimeters and microDiamond detectors were in very close agreement. This dosimetric method is a promising candidate for 3D quality assurance end-to-end tests in stereotactic and dynamic radiotherapy

High energy photon reference for radiation protection: Technical design of the LINAC beam and ionization chambers; And calculation of monoenergetic conversion coefficients

Conference of 32emes Journees des Laboratoires Associes de Radiophysiques et de Dosimetrie, LARD 2015 - 32nd Conference Days of the Radiophysics and Dosimetry Associate Laboratories, LARD 2015 ; Conference Date: 9 November 2015 Through 10 November 2015; Conference Code:123843International audienceIn this work, we present the results of the first part of a research project aimed at offering a complete response to dosimeters providers and nuclear physicists' demands for high-energy (6 - 9 MeV) photon beams for radiation protection purposes. Classical facilities allowing the production of high-energy photonic radiation (proton accelerators, nuclear reactors) are very rare and need large investment for development and use. A novel solution is proposed, consisting in the use of a medical linear accelerator, allowing a significant decrease of all costs.Using Monte Carlo simulations (MCNP5 and PENELOPE codes), a specifically designed electron-photon conversion target allowing for obtaining a high energy photon beam (with an average energy weighted by fluence of about 6 MeV) has been built for radiation protection purposes. Due to the specific design of the target, this "realistic" radiation protection high-energy photon beam presents a uniform distribution of air kerma rate at a distance of 1 m, over a 30 × 30 cm2 surface. Two graphite cavity ionizing chambers for ionometric measurements have been built. For one of these chambers, the charge collection volume has been measured allowing for its use as a primary standard. The second ionizing chamber is used as a transfer standard; as such it has been calibrated in a 60Co beam, and in the high energy photon beam for radiation protection.The measurements with these ionizing chambers allowed for an evaluation of the air kerma rate in the LINAC based high-energy photon beam for radiation protection: the values cover a range between 36 mGy/h and 210 mGy/h, compatible with radiation protection purposes.Finally, using Monte Carlo simulations, conversion coefficients from air kerma to dose equivalent quantities have been calculated in the range between 10 keV and 22.4 MeV, for the spectral distribution of the fluence corresponding to the beam produced by the linear accelerator of the LNE-LNHB.Cette étude propose une solution pour répondre à la demande des fabricants de dosimètres et des exploitants du nucléaire de disposer de champs de rayonnements photoniques de haute énergie (6 à 9 MeV) afin de caractériser (test de type) des dosimètres en vue de leurmise sur le marché et de les étalonner. Les installations de production de champs de rayonnements photoniques de haute énergie sont « lourdes » et très rares (accélérateur de protons, réacteurs nucléaires type piles piscines, …). L’utilisation d’un accélérateur médical permet de mutualiser l’utilisation entre radioprotection et radiothérapie en diminuant les coûts d’exploitation. Dans un premier temps, nous avons défini (par simulations Monte Carlo) puis réalisé un ensemble cible de conversion-atténuateur-égalisateur, qui permet d’obtenir un faisceau homogène de photons de haute énergie (énergie moyenne pondérée par la fluence égale à 6,17 MeV) pour la radioprotection à partir d’un faisceau d’électrons de 18 MeV, fourni par l’accélérateur linéaire médical du LNE-LNHB. Le faisceau ainsi obtenu est homogène en termes de kerma dans l’air sur une surface de 30 × 30 cm² à 1 m. Dans un second temps, nous avons fabriqué, assemblé et caractérisé deux chambres d’ionisation à cavité en graphite pour réaliser les mesures ionométriques. Pour l’une de ces chambres, nous avons mesuré le volume de collection des charges permettant ainsi de l’utiliser en tantqu’étalon primaire, l’autre chambre d’ionisation étant un étalon de transfert, elle a été étalonnée dans un faisceau de 60Co et dans le faisceau de photons de haute énergie pour la radioprotection. Les mesures effectuées avec les chambres d’ionisation ont permis d’évaluer lavaleur du débit de kerma dans l’air dans le faisceau de photons de haute énergie: celle-ci couvre une gamme entre 80 mGy/h et 210 mGy/h, ce qui est compatible avec les besoins dans ce domaine. Enfin, nous avons calculé à l’aide de simulations Monte-Carlo des coefficientsde conversion du kerma dans l’air vers les équivalents de dose pour des énergies de photons discrètes de 10 keV à 22,4 MeV dans des configurations géométriques spécifiques et pour la distribution spectrale de la fluence produite sur le LINAC du LNE-LNHB

EMPIR projekat 19NET04 MIRA – značaj projekta za uspostavljanje metrološke mreže

The 19NET04 MIRA Joint Network Project is a project within the EMPIR 2019 call. The main objectives of the project are to establish stakeholder dialogue, to develop the Strategic Research Agenda for the medical use of ionising radiation, to define how current European metrological services meet regulatory and stakeholder needs, to set up a knowledge-sharing programme for the stakeholders and to develop a plan for the European metrology research infrastructure via the European Metrology Network. The project addresses the strong need for a coordinated action on an international level in the different fields of ionising radiation which include medical applications, radiobiology and radiation protection.Projekat za uspostavljanje metrološke mreže 19NET04 MIRA predstavlja međunarodni projekat u okviru EMPIR 2019 poziva. Glavni ciljevi projekta jesu uspostavljanje dijaloga interesenata (stejkholdera), stvaranje strateškog plana razvoja za medicinske primene jonizujućeg zračenja, ispitivanje u kojoj meri trenutne metrološke mogućnosti evropskih instituta zadovoljavaju potrebe regulatornih tela i interesanata, postavljanje programa razmene znanja i razvoj plana za evropsku metrološku infrastrukturu putem evropske metrološke mreže. Projekat će dati odgovor na potrebu za koordiniranim aktivnostima na međunarodnom nivou u različitim oblastima primene jonizujućeg zračenja u medicini, radiobiologiji i zaštiti od zračenja.XXXI Симпозијум Друштва за заштиту од зрачења Србије и Црне Горе, 06-08. октобар 2021.Proceedings: [https://vinar.vin.bg.ac.rs/handle/123456789/9668