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The assessment of potential radon-hazardous environments is nowadays a critical issue in planning, monitoring, and developing appropriate mitigation strategies. Although some geological structures (e.g., fault systems) and other geological factors (e.g., radionuclide content, soil organic or rock weathering) can locally affect the radon occurrence, at the basis of a good implementation of radon-safe systems, optimized modelling at territorial scale is required. The use of spatial regression models, adequately combining different types of predictors, represents an invaluable tool to identify the relationships between radon and its controlling factors as well as to construct Geogenic Radon Potential (GRP) maps of an area. In this work, two GRP maps were developed based on field measurements of soil gas radon and thoron concentrations and gamma spectrometry of soil and rock samples of the Euganean Hills (northern Italy) district. A predictive model of radon concentration in soil gas was reconstructed taking into account the relationships among the soil gas radon and seven predictors: terrestrial gamma dose radiation (TGDR), thoron (220Rn), fault density (FD), soil permeability (PERM), digital terrain model (SLOPE), moisture index (TMI), heat load index (HLI). These predictors allowed to elaborate local spatial models by using the Empirical Bayesian Regression Kriging (EBRK) in order to find the best combination and define the GRP of the Euganean Hills area. A second GRP map based on the Neznal approach (GRPNEZ) has been modelled using the TGDR and 220Rn, as predictors of radon concentration, and FD as predictor of soil permeability. Then, the two GRP maps have been compared. Results highlight that the radon potential is mainly driven by the bedrock type but the presence of fault systems and topographic features play a key role in radon migration in the subsoil and its exhalation at the soil/atmosphere boundary.

Terrestrial gamma radiation is mostly due to radionuclides in soil and rocks, primarily the 238U, 235U and 232Th radioactive families and 40K. This radiation contributes 15% to public exposure from all ionizing radiation sources, considering global population. Moreover, it can be used to estimate radon flux and included as one of the quantities relevant to the geogenic radon hazard model. Therefore, effort has been put into developing maps of terrestrial gamma dose rate at the regional, national or European scale, using different input data and methods. In the present work, two distinct approaches to map terrestrial gamma dose rate have been tested in the Euganean Hills district of NE Italy. The first one is based on 41 in situ measurements of ambient dose equivalent rates using a rate meter equipped with a NaI scintillator probe. The second one estimates terrestrial gamma dose rate from the U, Th and K activity concentrations in rock samples collected at the same locations of the dose rates measurements. The results obtained indicate good agreement between the two approaches, and as such suggest that the UNSCEAR 2008 prescription to derive ambient dose equivalent rate from laboratory gamma measurements produces reliable data, provided that cosmic and fall-out contributions are included. Moreover, the study proved that mapping the ambient dose equivalent rate (or terrestrial gamma dose rate) using only one database – i.e. either measured data or estimates derived from radionuclide activity concentration – yields valid results.

We present a novel approach to solving Chandrasekhar’s problem in radiative transfer using the recently developed Theory of Functional Connections. The method is designed to elegantly and accurately solve the Linear Boundary Value Problem from the angular discretization of the integrodifferential Boltzmann equation for Radiative Transfer. The proposed algorithm falls under the category of numerical methods for the solution of radiative transfer equations. This new method’s accuracy is tested via comparison with the published benchmarks for Mie and Haze L scattering laws.

In electron beam welding a very intense pencil beam of electrons is driven onto the base metal, to melt it and produce the welding. In the interaction of the beam with the metal, strong bremsstrahlung emission of X-ray is generated. Here the generation is evaluated, and the KERMA in air at 1 m is predicted. Results show that a significant radiation hazard is present and serious radiation protection measures are needed.

In the volcanic area of the Euganean Hills district (100 km2), the indoor radon often exceeds the threshold level of 300 Bq/m3 stipulated by the Council Directive 2013/59/Euratom, thus suggesting the need to investigate the possible link between observed radon concentrations and the local geology (Trotti et al., 1998,1999; Strati et al., 2014). More recently, statistical and geostatistical analysis on rock samples identified high U, Th and K concentrations associated with areas characterised by trachyte and rhyolite lithologies (Tositti et al., 2017). With this contribution, we completed our investigation on the natural radioactivity in the Euganean Hills district extending the rocks dataset, performing on-site soil gas survey, and considering other important factors which can locally increase the radon occurrence, such as hydrothermal alterations, types of soils (e.g., geochemistry or presence of organic matters), and faults. Furthermore, we elaborated a Geogenic Radon Potential map to assess the local spatial relationships between the measured soil gas radon concentrations and seven proxy-variables: fault density (FD), total gamma radiation dose (TGDR), 220Rn (Tn), digital terrain mode (SLOPE), moisture index (MI), heat load index (HLI) and soil permeability (PERM). Empirical Bayesian Regression Kriging (EBRK) was used to develop the most accurate hazard map of the considered area, thus, providing the local administration an up-to-date decisional tool for the land use planning. For the high radon emission measured, the high density of dwelling, and its geomorphological features, the Euganean Hills district represented a very meaningful case of study. Trotti, F., Tanferi, A., Lanciai, M., Mozzo, P., Panepinto, V., Poli, S., Predicatori, F., Righetti, F., Tacconi, A., Zorzine, R., 1998. Mapping of areas with elevated indoor radon levels in Veneto. Radiat. Prot. Dosim. 78 (1), 11–14.Trotti, F., Tanferi, A., Bissolo, F., Fustegato, R., Lanciai, M., Mozzo, P., Predicatori, F., Querini, P., Righetti, F., Tacconi, A., 1999. A Survey to Map Areas with Elevated Indoor Radon Levels in Veneto, Radon in the Living Environment, 19-23 April 1999, Athens, Greece, 859–868.Strati V., Baldoncini M., Bezzon G.P, Broggini C., Buso G.P., Caciolli A., Callegari I., Carmignani L, Colonna T, Fiorentini G., Guastaldi E., Kaçeli Xhixhaf M., Mantovani F, Menegazzo R., Moub L., Rossi Alvarez C., Xhixha G., Zanon A., 2014. Total natural radioactivity, Veneto (Italy). Journal of Maps, Vol. 11, Issue 4, 545–551. http://doi.org/10.1080/17445647.2014.923348.Tositti L., Cinelli G., Brattich E., Galgaro A., Mostacci D., Mazzoli C., Massironi M., Sassi R., 2017. Assessment of lithogenic radioactivity in the Euganean Hills magmatic district (NE Italy). J. Environ. Radioact. 166, 259–269. https://doi.org/10.1016/j.jenvrad.2016.07.011

The Euganean Hills of North East Italy have long been recognised as an area characterized by a higher than average natural radiation background. This is due to two main reasons: a) primary lithogenic radiation due to rhyolitic and trachytic outcrops, which are “acidic alkaline” magmatic rocks potentially enriched in uranium and thorium; b) secondary sources related to a geothermal field – widely exploited for spa tourism in the area since the Roman age – producing surface release of radon-enriched fluids. Though radioactivity levels in the Euganean district have been often investigated in the past – including recent works aimed at assessing the radiation doses from radon and/or total gamma radiation – no effort has been put so far into producing a thorough assessment linking radiation protection data to geological-structural features (lithology, faults, water, organic matter content, etc.). This work represents the first part of the interdisciplinary project “Geological and geochemical control on Radon occurrence and natural radioactivity in the Euganean Hills district (North-Eastern Italy)”, aimed at producing detailed results of the actual radiation levels in connection mainly with lithological parameters. A detailed sampling strategy, based on lithostratigraphy, petrology and mineralogy, has been adopted. The 151 rock samples collected were analyzed by high resolution γ-ray spectrometry with ex situ HPGe detectors. Statistical and geostatistical analyses were performed, and outlier values of U and Th – possibly associated with anomalies in the geological formation – were identified. U, Th and K concentration maps were developed using both the entire database and then again after expunging the outliers; the two were then compared. In all maps the highest values can be associated to trachyte and rhyolite lithologies, and the lowest ones to sedimentary formations. The external dose due to natural radionuclides in the soil – the so called terrestrial gamma dose rate – has been calculated using the U, Th and K distribution measured in the bedrock samples.

Many industrial by-products contain Naturally Occurring Radioactive Materials (NORM) that normally represent a cost in terms of monitoring, risk management and storage. When included in new mix designs of bricks, these materials may become a valuable sustainable resource. Before marketing, companies involved in development and commercialization of these new building materials ensure safety related to radiation, usually by assessing radon-related risk. According to the Council Directive 2013/59/Euratom, both raw materials and final products used in building constructions need to be tested for activity concentration. The present work explores the radionuclide concentration and the radon exhalation of bricks obtained recycling different types of potentially radioactive wastes: i) trachyte as by-product resulting from quarrying operations, and ii) two different types of industrial sludge derived from ceramic tiles industry. Raw materials were studied to foresee any potential radioactive risk derived from their use as secondary raw materials, while bricks were investigated to assess the influence of mineralogy and texture on their radioactive properties and their effective radon-risk. The results obtained here show that, although radon emanation in bricks is primarily determined by radionuclide concentration in the raw materials, textural features significantly affect radon mobility and exhalation.

Medical linear accelerators are increasingly used in radiotherapy. During the operational life of the accelerator, the different components of the LINAC head become radioactive due to photonuclear reactions. Activation induced has to be evaluated to assess not only the dose due to residual activation but also the amount of radioactive waste that has to be managed in the dismantling phase of the facility. The aim of this work is to define a Monte Carlo approach for the preliminary assessment of activation levels of a LINAC head. In this work the MC code FLUKA was used to simulate the Elekta Precise Treatment System 15 MeV LINAC installed in 2004 at the Bellaria Hospital (Bologna, IT) and routinely used in radiotherapy treatments. The activation of the LINAC head was assessed in each component after 15 years of operation. The main long-lived radionuclides found in head components are W-181, Re-184, Ni-63, Co-57, Fe-55, Mn-54, while short-lived radionuclides are W-187, W-185, W-179, Re-188, Re-186, Re-184, Cu-64, Cu-62, Ni-65, Ni-57, Cr-55 and Mn-56. As expected the most active component is the target while no considerable activation were found in the ionization chamber and in the wedge.

The departure from ideal gas behavior is described by several known equations of state (EoS), developed from a combination of theoretical considerations and experimental correlations. In this work, a different approach, in the framework of kinetic theory, is proposed: from a pairwise potential of the Lennard–Jones type, the interaction between molecules is accounted for by means of a self-consistent force field. The propagation of a perturbation wave in the dense gas or liquid of unperturbed density n0 is described and the isothermal propagation velocity is determined. An EoS is derived and compared to the van der Waals EoS, of which it is found to reproduce the main features.

During the operational life of a PET cyclotron, the concrete walls of the vault are activated by secondary neutrons. For the dismantling of such accelerator facilities, a considerable amount of low level solid radioactive waste has to be characterized and disposed. To decrease future dismantling costs and complexity, the amount of radioactive waste has to been prospectively evaluated in the design phase, then confirmed at the time of planning decommissioning. In this work, the Monte Carlo code Fluka was used for the assessment of the activation of the bunkers of two different facilities: the 16.5 MeV GE PETtrace at S. Orsola-Malpighi Hospital in Bologna and the 18 MeV IBA Cyclone 18/18 HC at the Bern University Hospital (Inselspital). The simulations were validated by means of experimental measurements performed in our previous works: non-destructive, in field measurements using a portable CZT detector were performed in Bologna; while core drilling samples were extracted from the bunker and measured in laboratory with an HPGe detector in Bern. The activity of the most important radionuclides in the concrete walls of the bunker, namely Eu-152, Mn-54, Co-60, Sc-46, Zn-65 and Cs-134 resulted within the range of 0.01 – 2 Bq/g. The consistency between Monte Carlo results and experimental measurements was within a factor 2 - 3 for most radionuclides, except for Eu-152, Sc-46, Zn-65. The activity concentrations estimated at each position considered exceeds the clearance levels of the new Directive 2013/59/Euratom. The results of this work demonstrate that Monte Carlo simulations based on FLUKA are adequate to assess the residual activation levels, a fundamental information to foresee, plan and optimize the decommissioning of a cyclotron based PET centers.

An innovative epidermal surface treatment based on 188Re has been recently developed for squamous cell carcinomas of the skin. The planning and delivery of the treatment requires an accurate knowledge of the source activity and thus proper calibration of activity meters. However, reference sources for calibration purposes are not always available, as in the case of short-lived radionuclides. The aim of this work is to determine the calibration factors for 188Re by comparison of measurements with an independently calibrated HPGe spectrometer. Calibration factors were experimentally determined for two different activity meters, a Capintec CRC15 and a MecMurphil MP-DC. This study was conducted on a Rhenium-188 compound produced by OncoBeta® GmbH for Rhenium-SCT® therapy. The final calibration factors, relative to 137Cs, for the MecMurphil MP-DC were: 4.35 ± 0.06 for point-like sources and 4.48 ± 0.09 for 5 mL solutions. While the final calibration factors for the Capintec CRC15 were: 4.12 ± 0.07 for point-like sources and 4.60 ± 0.10 for 5 mL solutions. With the presented method, we managed to determine calibration factors with an uncertainty below 3%.

In this work a set of calibration constants to measure the 18F airborne activity in straight ducts with square section are computed by means of a Geant4 simulation and provided for different duct lengths. The calibration constants are compared with analytical calculations and experimental measurements. The simulated calibration constants provide a useful cross-check for the actual calibration of airborne monitoring systems in ducts, which is practically complex and can be affected by large uncertainties.

Lead-210 is a naturally occurring radionuclide of great importance for environmental studies. Its vertical distribution in soil combined with that of Radium–226 may provide useful information on radon exhalation from the ground, or radon carried by ground water. Previous research has shown that natural radioactivity levels–in particular Lead–210 and Radium–226 activity in the ground–may be higher near hot springs. In this work two different locations near hot springs were selected for soil sampling: Kamena Vourla and Thermopylae, both in Greece. Depending on the special soil characteristics of each sampling location, it was decided to collect soil cores up to a depth of 20 cm from Kamena Vourla, and surface soil from Thermopylae.The soil cores were then sectioned into 1 cm slices, while the surface soil samples were separated into seven particle size fractions by dry sieving. All samples were analysed by high resolution gamma-ray spectrometry at the Nuclear Engineering Department of the National Technical University of Athens, using an XtRa germanium detector and a Low Energy germanium detector, to determine: (a) the terrestrial natural radionuclides Thorium–234, Radium–226, Lead-210, Radium–228, Thorium–228 and Potassium–40, (b) the cosmogenic radionuclide Beryllium–7, and (c) the artificial radionuclides Cesium–137 and Ruthenium–106. It is worth mentioning that, the Ruthenium–106 that was detected in samples collected from both sampling locations is the result of an accidental release over Europe, apparently originated in Russia, a few days before the sampling took place. The vertical profile of the radionuclides obtained from the core sample analysis indicated a disturbance in the first 7 cm of soil, while at greater depth the concentrations for all radionuclides were as expected. Lead-210 activity was higher than that of Radium–226, showing a disruption in the radioactive equilibrium, as expected. The analysis of the size-fractionated samples showed a higher activity concentration of Lead–210 and Cesium–137 in the finer fractions. The radioactive equilibrium between Thorium–234, Radium–226, and Lead–210 was found to be significantly disturbed in all size fractions.

Radionuclides handled in nuclear medicine departments are often characterized by high volatility and short half-life. It is generally difficult to monitor directly the intake of these short-lived radionuclides in hospital staff: this makes measuring air contamination of utmost interest. The aim of the present work is to provide a method for the evaluation of internal doses to workers in nuclear medicine, by means of an air activity sampling detector, to ensure that the limits prescribed by the relevant legislation are respected. A continuous air sampling system measures isotope concentration with a Nal(TI) detector. Energy efficiency of the system was assessed with GEANT4 and with known activities of 18 F. Air is sampled in a number of areas of the nuclear medicine department of the IRST-IRCCS hospital (Meldola- Italy). To evaluate committed doses to hospital staff involved (doctors, technicians, nurses) different exposure situations (rooms, times, radionuclides etc) were considered. After estimating the intake, the committed effective dose has been evaluated, for the different radionuclides, using the dose coefficients mandated by the Italian legislation. Error propagation for the estimated intake and personal dose has been evaluated, starting from measurement statistics.

none 9 no In a Plasma Focus device the plasma collapses into the pinch where it reaches thermonuclear conditions for a few tens of nanoseconds, becoming a multi-radiation source. The nature of the radiation generated depends on the gas filling the chamber and the device working parameters. The self-collimated electron beam generated in the backward direction with respect to the plasma motion is one of the main radiation sources of interest also for medical applications. The electron beam may be guided against a high Z material target to produce an X-ray beam. This technique offers an ultra-high dose rate source of X-rays, able to deliver during the pinch a massive dose (up to 1 Gy per discharge for the PFMA-3 test device), as measured with EBT3 GafchromicⒸfilm tissue equivalent dosimeters. Given the stochastic behavior of the discharge process, a reliable on-line estimate of the dose-delivered is a very challenging task, in some way preventing a systematic application as a potentially interesting therapy device. This work presents an approach to linking the dose registered by the EBT3 GafchromicⒸfilms with the information contained in the signal recorded during the current discharge process. Processing the signal with the Wigner-Ville distribution, a spectrogram was obtained, displaying the information on intensity at various frequency scales, identifying the band of frequencies representative of the pinch events and define some patterns correlated with the dose. Sumini, M.; Mostacci, D.; Tartari, A.; Mazza, A.; Cucchi, G.; Isolan, L.; Buontempo, F.; Zironi, I.; Castellani, G. Sumini, M.; Mostacci, D.; Tartari, A.; Mazza, A.; Cucchi, G.; Isolan, L.; Buontempo, F.; Zironi, I.; Castellani, G.

During the operational life of a PET Cyclotron, the concrete walls of its vault are activated by secondary neutrons. For this reason when considering dismantling of such accelerators, a considerable amount of low level solid radioactive waste has to be characterized and disposed. To decrease future dismantling costs, the amount of radioactive waste has to be evaluated in advance to define an optimum decommissioning strategy. Aim of this work is to develop methodologies for the preliminary assessment of activation induced in a bunker via experimental measurements. Two different facilities were studied and different approaches were adopted: non-destructive, in field measurements using a portable CZT detector were performed in the bunker of a 16.5 MeV GE PETtrace (S. Orsola-Malpighi Hospital of Bologna); while core drilling samples were extracted from the bunker of an 18 MeV IBA Cyclone 18 H C (Inselspital in Bern) and measured in laboratory with an HPGe detector. The principal long-lived radionuclides found in concrete were Eu-152, Mn-54, Co-60, Sc-46, Cs-134 with activity concentrations comprised between 0.01 and 0.6 Bq/g. In all performed measurements the total activity concentration exceed the clearance level of Directive (2013)/59/Euratom. Considering a hypothetical decommissiong of the two facilities, the amount of low lever radioactive waste estimated was about 93 m3 in the case of S. Orsola-Malpighi, while about 58 m3 for Insespital facility. Both the methodologies have proved to be adequate for the purposes.

No abstract

In the classical case, the hydrostatic pressure of an ideal gas is defined as being two-thirds of the specific kinetic energy of the gas: p = 2/3 n < Uk >, where < Uk > is the average kinetic energy of the particles. However, this is no longer the case when relativistic cases are considered. Further concerns may be raised by quantum considerations. In the present paper, both pressure and kinetic energy are calculated taking the appropriate averages weighted with the equilibrium distribution function of the gas. For the purpose of this work the quantum relativistic Fermi–Dirac and Bose–Einstein distribution functions, will be considered for the cases of bosons and weakly degenerate fermions. Integration yields results in a closed form containing modified Bessel functions. A large-argument approximation is then taken, leading to an equation of state composed of the classic part plus correction terms.

[EN] While the founding members of CHERNE gradually retire, the memory of the early steps of the network should not be lost. CHERNE (`Cooperation for Higher Education on Radiological and Nuclear Engineering¿) is the product of a specific Erasmus activity possible in the early 2000s: the intensive programmes (IP). The first step was a collaboration of three partners (Czech Technical University CTU, Institut Supérieur Industriel de Bruxelles ISIB, Universitat Politècnica de València UPV) organising in 2002 the 3-year IP `PAN: Practical Approach to Nuclear techniques¿, soon integrating two other partners (Aachen University of Applied Science AcUAS, XIOS Hogeschool Limburg). A second IP `SPERANSA: Stimulating Practical Expertise in RAdiation and Nuclear SAfety¿ was first organised without Erasmus support in 2005. A workshop was held in 2005 at UPV, including colleagues from other universities. Its main goal was to put in contact professors and researchers from European Institutions in order to share experiences in education and research in Radiation Protection and Nuclear Engineering. The creation of an informal group of universities to develop activities for the benefit of students was discussed. With the addition of Università degli Studi di Bologna (UniBo) to the initial group, the CHERNE network was created. It attracted rapidly more members (6 adhesions in 2006). CHERNE was conceived as a non-formal wide-scope open network, easily integrating new members, offering affordable activities to the students and mostly relying on Erasmus subsidies. The main goal was still the organisation of Erasmus IP¿s based on practical activities, benefitting of the access to big experimental facilities offered by several partners, like reactors, accelerators, or a radiochemical laboratory. SPERANSA was organised from 2006 to 2008, `JUNCSS: JÜlich Nuclear Chemistry Summer School¿ from 2007 to 2011 and `RAPIX-NOCOS: Radiation protection in non-conventional sectors¿ in 2007 and 2008 without Erasmus support. The annual workshops triggered exchanges between partners and attracted more institutions. The first workshops saw intense discussions about the network organisation and the types of activities that could be organised. A kind of maturity was reached from 2008.

Vulsini Volcanic district in Northern Latium (Central Italy) is characterized by high natural radiation background resulting from the high concentrations of uranium, thorium and potassium in the volcanic products. In order to estimate the radon radiation risk, a series of soil gas radon measurements were carried out in Bolsena, the principal urban settlement in this area NE of Rome. Soil gas radon concentration ranges between 7 and 176 kBq/m(3) indicating a large degree of variability in the NORM content and behavior of the parent soil material related in particular to the occurrence of two different lithologies. Soil gas radon mapping confirmed the existence of two different areas: one along the shoreline of the Bolsena lake, characterized by low soil radon level, due to a prevailing alluvial lithology; another close to the Bolsena village with high soil radon level due to the presence of the high radioactive volcanic rocks of the Vulsini volcanic district. Radon risk assessment, based on soil gas radon and permeability data, results in a map where the alluvial area is characterized by a probability to be an area with high Radon Index lower than 20 %, while probabilities higher than 30 % and also above 50 % are found close to the Bolsena village.

Radiation protection (RP) in the use of medical cyclotrons involves many aspects both in the routine use and for the decommissioning of a site. Guidelines for site planning and installation, as well as for RP assessment, are given in international documents; however, the latter typically offer analytic methods of calculation of shielding and materials activation, in approximate or idealised geometry set-ups. The availability of Monte Carlo (MC) codes with accurate up-to-date libraries for transport and interaction of neutrons and charged particles at energies below 250 MeV, together with the continuously increasing power of modern computers, makes the systematic use of simulations with realistic geometries possible, yielding equipment and site-specific evaluation of the source terms, shielding requirements and all quantities relevant to RP at the same time. In this work, the well-known FLUKA MC code was used to simulate different aspects of RP in the use of biomedical accelerators, particularly for the production of medical radioisotopes. In the context of the Young Professionals Award, held at the IRPA 14 conference, only a part of the complete work is presented. In particular, the simulation of the GE PETtrace cyclotron (16.5 MeV) installed at S. Orsola-Malpighi University Hospital evaluated the effective dose distribution around the equipment; the effective number of neutrons produced per incident proton and their spectral distribution; the activation of the structure of the cyclotron and the vault walls; the activation of the ambient air, in particular the production of 41Ar. The simulations were validated, in terms of physical and transport parameters to be used at the energy range of interest, through an extensive measurement campaign of the neutron environmental dose equivalent using a rem-counter and TLD dosemeters. The validated model was then used in the design and the licensing request of a new Positron Emission Tomography facility.

OBJECTIVE: When handling Y-labelled and Lu-labelled radiopharmaceuticals, skin exposure is mainly due to β-particles. This study aimed to investigate the equivalent dose saving of the staff when changing from an essentially manual radiolabelling procedure to an automatic dose dispenser (ADD). MATERIALS AND METHODS: The chemist and physician were asked to wear thermoluminescence dosimeters on their fingertips to evaluate the quantity of Hp(0.07) on the skin. Data collected were divided into two groups: before introducing ADD (no ADD) and after introducing ADD. RESULTS: For the chemist, the mean values (95th percentile) of Hp(0.07) for no ADD and ADD are 0.030 (0.099) and 0.019 (0.076) mSv/GBq, respectively, for Y, and 0.022 (0.037) and 0.007 (0.023) mSv/GBq, respectively, for Lu. The reduction for ADD was significant (t-test with P

This work was aimed at characterizing and validating a very compact, USB-powered, CdZnTe detector for gamma-ray spectrometry applications in radiopharmacy. A GR1 model (by KromekTM, Sedgefield, UK) was utilized. The detector was calibrated in energy and efficiency. Samples of [18F]FDG and [68Ga]-DOTANOC were measured to assess the detector’s suitability in radionuclidic purity measurements. The energy resolution and the efficiency obtained are fully adequate for quality control of positron emission tomography radiopharmaceuticals. Results of [18F]FDG and [68Ga]-DOTANOC samples proved to be comparable to those obtained using high-purity Germanium detectors. The performance of the detector and its very compact size make this type of device an extremely attractive tool for QC applications in radiopharmacy.

During the operational life of a PET Cyclotron, the concrete walls of the cyclotron vault are activated by the secondary neutron flux interacting with rare earths and metals present in the concrete or in reinforcement bars. For this reason when considering dismantling of such accelerators, the amount of radioactive waste has to be evaluated in advance to identify any critical issues or possible countermeasures to be taken to define an optimum decommissioning strategy. The aim of this work is to define a non-destructive in situ measurement methodology for a preliminary activation assessment of a cyclotron bunker with no need for core drilling. A very compact, USB-powered, CdZnTe (CZT) detector for gamma-ray spectrometry was used for the activation assessment of the site of installation of a GE PETtrace (16.5 MeV) cyclotron, routinely used in the production of positron-emitting radionuclides. Because of the complexity of measurement geometry, the efficiency calibration of the detector was performed via Monte Carlo (MC) simulations. The detector was accurately modelled using FLUKA, including a 5 cm lead shielding set-up. The MC model of the detector was validated for a wide range of energies and different source geometries, showing discrepancies below 5% for all tested sources. The efficiency curve for wall activation measurements was calculated, allowing a quantitative evaluation of activity concentration.

In road and railway tunnel excavation, personnel are exposed to natural radiation. Exposure can have varying degrees of significance, as naturally occurring radioactive material (NORM) content may vary by more than one order of magnitude depending on local lithology and, as far as radon is concerned, depending also on features of more distant bedrocks involved in radon convection. Radon exhalation and build up in the confined environment of the tunnel is affected by permeability of rocks, which is highly variable with lithology. Excavation methods as well have an impact on workers’ exposure, due both to exposure time and to protection afforded by the equipment. Therefore, it is of interest to develop a method to predict radon levels to characterize the work area. Since drill cores are invariably taken before excavation begins, for a preliminary assessment of the geology involved, a method is proposed here for predicting radon levels, based on NORM and exhalation measurements in drill core samples, and on the geometry of the tunnel to be excavated. An experimental campaign is under way on a railway tunnel under construction in northwestern Italy: preliminary results will be presented and predicted values compared to experimental measurements.

An experimental device for plasma treatment of low and intermediate level radioactive waste was built and tested in several design variations. The laboratory device is designed with the intention to study the general effects and difficulties in a plasma incineration set-up for the further future development of a larger scale pilot plant. The key part of the device consists of a novel microwave plasma torch driven by 200 W electric power, and operating at atmospheric pressure. It is a specific design characteristic of the torch that a high peak temperature can be reached with a low power input compared to other plasma torches. Experiments have been carried out to analyze the effect of the plasma on materials typical for operational low-level wastes. In some preliminary cold tests the behavior of stable volatile species e. g., caesium was investigated by TXRF measurements of material collected from the oven walls and the filtered off-gas. The results help in improving and scaling up the existing design and in understanding the effects for a pilot plant, especially for the off-gas collection and treatment.

Propagation of sound waves through an ideal gas is studied in the framework of kinetic theory, starting from the integral representation of the Boltzmann Equation (BE). The distribution function is calculated and used to obtain the dispersion relation of density waves. The parallel existence of temperature waves (in some contexts referred to as second sound) is also part of this investigation. Temperature waves are found to exist; the phase difference between density and temperature waves is determined.

Starting from the modified Lennard–Jones potential, a method is proposed to calculate the internal energy in liquids, and from this the specific heat. The method is applied to liquid helium-4 and the well-known shape of the “lambda point” is reproduced.

The international monitoring system (IMS) has been developed to verify compliance with the comprehensive nuclear test-ban treaty (CTBT) and radionuclide monitoring stations are the smoking gun for underground nuclear explosions identification. One of the main objectives of the verification regime is to improve the sensitivity of measurements providing background reduction and, as a result, decrease the minimum detectable activity (MDA) values. At this ENEA laboratory an anticoincidence system has been developed: the system is comprised of a high purity germanium (HPGe) detector surrounded by a low–background shield and two plastic scintillators able to detect coincident cosmic-ray interactions. Tests conducted with the anticoincidence system have shown a reduction of the Compton continuum that contributes to the spectrum background and the measured MDA values, compared to those obtained using the standard system, decreased for all the four radioxenon isotopes. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Irradiation with γ rays is widely used in the sterilization of a large variety of products and materials in the field of medical supplies, pharmaceuticals, cosmetics, food industry and cultural heritage. It is also applied on wood materials, with the purpose of improving their shelf-life, by lowering the microbial charge and hence the microbial-related deterioration rate. A fundamental issue when applying γ rays is the preservation of the chemico-physical as well as of the structural and mechanical properties of the materials irradiated, since a significant change of properties may jeopardize the use of the materials for the purpose intended. To this end, in this paper, we analyzed the chemico-physical properties of four different types of wood used for the construction of musical instruments namely fir, maple, poplar and durmast oak under increasing doses of γ rays. In detail, the effect of incremental radiation doses was evaluated by comparing the results obtained by acoustic tests with those providing information at molecular level, i.e., cyclic voltammetry, linear square voltammetry and infrared spectroscopy. Moreover, in this work, the glucose released as a result of the degradation of wood cellulose and hemicellulose, has been analyzed for the first time, with an innovative tool, based on the use of a Gellan gel. The integrated approach presented here, based on both traditional and innovative techniques has proven to be highly efficient in providing a complete picture of wood behavior following γ-ray irradiation, at both the macroscopic and the molecular level.

Biomedical cyclotrons for production of Positron Emission Tomography (PET) radionuclides and radiotherapy with hadrons or ions are widely diffused and established in hospitals as well as in industrial facilities and research sites. Guidelines for site planning and installation, as well as for radiation protection assessment, are given in a number of international documents; however, these well-established guides typically offer analytic methods of calculation of both shielding and materials activation, in approximate or idealized geometry set up. The availability of Monte Carlo codes with accurate and up-to-date libraries for transport and interactions of neutrons and charged particles at energies below 250 MeV, together with the continuously increasing power of nowadays computers, makes systematic use of simulations with realistic geometries possible, yielding equipment and site specific evaluation of the source terms, shielding requirements and all quantities relevant to radiation protection. In this work, the well-known Monte Carlo code FLUKA was used to simulate two representative models of cyclotron for PET radionuclides production, including their targetry; and one type of proton therapy cyclotron including the energy selection system. Simulations yield estimates of various quantities of radiological interest, including the effective dose distribution around the equipment, the effective number of neutron produced per incident proton and the activation of target materials, the structure of the cyclotron, the energy degrader, the vault walls and the soil. The model was validated against experimental measurements and comparison with well-established reference data. Neutron ambient dose equivalent H ⁎ (10) was measured around a GE PETtrace cyclotron: an average ratio between experimental measurement and simulations of 0.99±0.07 was found. Saturation yield of 18 F, produced by the well-known 18 O(p,n) 18 F reaction, was calculated and compared with the IAEA recommended value: a ratio simulation to IAEA of 1.01±0.10 was found.

Ms. Ref. No.: JENVRAD-D-11-00380R2 The follow-up of Fukushima radioactive plume resulting from the 11th March 2011 devastating tsunami is discussed for two Italian stations in the northern Apennines: Mt. Cimone (Modena) and Montecuccolino (Bologna). Radioactivity data collected at both stations are described, including comparison between local natural background of airborne particulate and artificial radioactivity referable to the arrival of the radioactive plume and its persistence and evolution. Analysis of back-trajectories was used to confirm the arrival of artificial radionuclides following atmospheric transport and processing. The Fukushima plume was first detected on 3rd April 2011 when high volume sampling revealed the presence of the artificial radionuclides 131I, 137Cs and 134Cs. The highest activity concentrations of these nuclides were detected on 5th April 2011 at the Montecuccolino site. Fukushima radioactivity data at the two stations were usually comparable, suggesting a good vertical mixing of the plume; discrepancies were occasional and attributed to different occurrence of wet removal, typically characterized by a scattered spatial pattern. To understand the relevance to the local population of the extra dose due to the Fukushima plume, atmospheric activities of the related artificial nuclides were compared to those of the main natural radionuclides in ambient particulate, and found to be lower by over one order of magnitude. Radiation doses referable to Fukushima, maximized for a whole year occurrence at the highest activity level observed at our stations in the weeks affected by the Japanese plume, were estimated at 1.1 μSv/year.

The Sutherland approximation to the van der Waals forces is applied to the derivation of a self-consistent Vlasov-type field in a liquid filling a half space, bordering vacuum. The ensuing Vlasov equation is then derived, and solved to predict the behavior of the density at and in the vicinity of the liquid-vacuum interface. A numerical solution to the Vlasov equation is also produced and the density profile shown and discussed., Comment: 9 pages, 1 figure

He-4 is known to become superfluid at very low temperatures. This effect is now generally accepted to be connected with BEC (Bose-Einstein Condensation). The dispersion relation of pressure waves in superfluid He-4 has been determined at 1.1 {\deg}K by Yarnell et al., and exhibits a non monotonic behavior - with a maximum and a minimum - usually explained in terms of excitations called rotons, introduced by Landau. In the present work an attempt is made to describe the phenomenon within the bohmian interpretation of QM. To this end, the effects of the intermolecular potential, taken to be essentially of the Lennard-Jones type modified to account for molecule finiteness, are included as a Vlasov-type self-consistent field. A dispersion relation is found, that is in quite good agreement with Yarnell's curve. Keywords: Bohm potential; Intermolecular potential; Dispersion relation; Superfluid He-4; First sound. PACS: 05.30.Jp; 05.20.Dd; 03.75.Kk; 67.25.dt, Comment: 17 pages 3 figures (embedded)

A numerical computation of the Doppler convolution of the elastic scattering kernel based on the gas model is presented, without making assumptions on the variation of the cross section with energy and for a general scattering law in the center of mass system. The range of integration has been optimized employing a numerical cutoff, allowing for a faster numerical evaluation of the convolution integral. Legendre moments of the transfer kernel are subsequently obtained by direct quadrature and a numerical analysis of the convergence is presented.

A new independent derivation of Blackshow–Murray’s classical formula for the Doppler-broadening elastic scattering kernel is given, including an extension to anisotropy of scattering in the center of mass. Also, the puzzling behavior of the secondary angular and energy neutron distribution about the lower resonances of heavy isotopes is explained by introducing an asymptotic ordering, which includes on the same foot thermal agitation and resonance effects, and by a detailed analysis for the case of collinear scattering. Finally, we use Lagrange polynomial interpolations for a fast and accurate calculations of the angular moments of the kernel. Results for 238 U are presented, analyzed and compared to those in the existing literature, for both isotropic an anisotropic scattering in the center of mass.

In the planning of a new cyclotron facility, an accurate knowledge of the radiation field around the accelerator is fundamental for the design of shielding, the protection of workers, the general public and the environment. Monte Carlo simulations can be very useful in this process, and their use is constantly increasing. However, few data have been published so far as regards the proper validation of Monte Carlo simulation against experimental measurements, particularly in the energy range of biomedical cyclotrons. In this work a detailed model of an existing installation of a GE PETtrace 16.5 MeV cyclotron was developed using FLUKA. An extensive measurement campaign of the neutron ambient dose equivalent H ∗ (10) in marked positions around the cyclotron was conducted using a neutron rem-counter probe and CR39 neutron detectors. Data from a previous measurement campaign performed by our group using TLDs were also re-evaluated. The FLUKA model was then validated by comparing the results of high-statistics simulations with experimental data. In 10 out of 12 measurement locations, FLUKA simulations were in agreement within uncertainties with all the three different sets of experimental data; in the remaining 2 positions, the agreement was with 2/3 of the measurements. Our work allows to quantitatively validate our FLUKA simulation setup and confirms that Monte Carlo technique can produce accurate results in the energy range of biomedical cyclotrons.

Gamma radiation is a most efficient tool for sterilization, and especially effective on infesting pest, as it also kills the eggs. However, the large radiation doses entailed (tens of kilogray and up) might have adverse effects on desirable properties of wood. Of particular interest are the acoustic properties, as radiation would otherwise appear to be the perfect tool for the sterilization of musical instruments. The present investigation was aimed at determining the effects on acoustic and mechanical properties. Samples of four different wood species – poplar, oak, fir and maple – were prepared selecting wood completely free of visually detectable defects and subjected to incremental dose levels, reaching 25, 50, 100 and 200 kGy. A further set of samples were subjected to 200 kGy in one go, to investigate possible differences with incremental doses. Irradiation was conducted at an industrial irradiation facility, operating with a cobalt-60 source of the order of the megacurie. The mechanical tests were designed to measure the elastic modulus and the bending strength as well as force and displacement at rupture. Acoustic tests were developed specifically for this experiment, with the purpose of measuring the vibrational modes of the samples. All the samples exhibited discoloration and noticeable changes in properties: rigidity increased, load to rupture decreased, the material became more brittle and effects increased with increasing dose. The acoustic tests revealed a shift toward higher frequencies of all the vibrational modes, and this was exhibited for all wood species investigated. No meaningful difference was observed between the samples treated with incremental doses up to a total of 200 kGy and with a single 200 kGy dose.

In the Bayesian approach to solving inverse problems to parameter estimation, the quantities we seek to retrieve are considered as random variables. The randomness includes the uncertainty regarding their true values. We intend to use this approach to perform inversion of coupled radiative and heat transfer models for asteroid regoliths and lakes. The Bayesian inversion of this kind of models allows estimating optical and thermodynamic properties of the systems considered, and also allows finding any correlation among these properties; that would be quite difficult to find with the classical approaches.

The Monte Carlo code FLUKA is used to simulate the production of a number of positron emitting radionuclides, 18 F, 13 N, 94 Tc, 44 Sc, 68 Ga, 86 Y, 89 Zr, 52 Mn, 61 Cu and 55 Co, on a small medical cyclotron with a proton beam energy of 13 MeV. Experimental data collected at the TR13 cyclotron at TRIUMF agree within a factor of 0.6 ± 0.4 with the directly simulated data, except for the production of 55 Co, where the simulation underestimates the experiment by a factor of 3.4 ± 0.4. The experimental data also agree within a factor of 0.8 ± 0.6 with the convolution of simulated proton fluence and cross sections from literature. Overall, this confirms the applicability of FLUKA to simulate radionuclide production at 13 MeV proton beam energy.

We present highly accurate solutions to the neutral particle transport equation in a half-space. While our initial motivation was in response to a recently published solution based on Chandrasekhar's H-function, the presentation to follow has taken on a more comprehensive tone. The solution by H-functions certainly did achieved high accuracy but was limited to isotropic scattering and emission from spatially uniform and linear sources. Moreover, the overly complicated nature of the H-function approach strongly suggests that its extension to anisotropic scattering and general sources is not at all practical. For this reason, an all encompassing theory for the determination of highly precise benchmarks, including anisotropic scattering for a variety of spatial source distributions, is presented for particle transport in a half-space. We illustrate the approach via a collection of cases including tables of 7-place flux benchmarks to guide transport methods developers. The solution presented can be applied to a considerable number of one and two half-space transport problems with variable sources and represents a state-of-the-art benchmark solution.

A pulsed plasma device “Mather type” Plasma Focus (PFMA-3) has been recently put into operation for a possible application to radiotherapy treatment of malignant cells. Some preliminary data about the better efficiency of PFMA-3 to induce cell damage compared to conventional X-ray devices (XRT) have already been obtained in breast adenocarcinoma cell line MCF-7. To better assess the advantage of the very high dose rate delivered by PFMA-3, we explored its biological effectiveness on a human melanoma cell line SK-Mel28, well known for its radioresistance, in comparison with conventional sources.

In this work a compact system was designed for bulk sample analysis using the technique of PGNAA. The system consists of (252)Cf fission neutron source, a moderator/reflector/filter assembly, and a suitable enclosure to delimit the resulting neutron beam. The moderator/reflector/filter arrangement has been optimised to maximise the thermal neutron component useful for samples analysis with a suitably low level of beam contamination. The neutron beam delivered by this compact system is used to irradiate the sample and the prompt gamma rays produced by neutron reactions within the sample elements are detected by appropriate gamma rays detector. Neutron and gamma rays transport calculations have been performed using the Monte Carlo N-Particle transport code (MCNP5).