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Background. The role of prolactin (PRL) on tissue injury and repair mechanisms in multiplesclerosis (MS) remains unclear. The aim of this work was to investigate the relationship between PRL plasma levels and brain damage as measured by magnetic resonance imaging (MRI). Methods. We employed a chemiluminescence immunoassay for measuring plasma levels of PRL. We used a 1.5 T scanner to acquire images and Jim 4.0 and SIENAX software to analyse them. Results. We included 106 women with relapsing remitting (RR) MS and stable disease in the lasttwo months. There was no difference in PRL plasma levels between patients with and without gadolinium enhancement on MRI. PRL plasma levels correlated with white matter volume (WMV) (rho = 0.284, p=0.014) but not with grey matter volume (GMV). Moreover, PRL levels predicted changes in WMV (Beta: 984, p=0.034). Conclusions. Our data of a positive association between PRL serum levels and WMV support the role of PRL in promoting myelin repair as documented in animal models of demyelination. The lack of an increase of PRL in the presence of gadolinium enhancement, contrasts with the view considering this hormone as an immune-stimulating and detrimental factor in the inflammatory process associated with MS.

The operation of particle and ion accelerators involves the activation of the air in the bunker where the equipment is located and then the planned release into the atmosphere of radioactive effluents in gaseous form. The evaluation of the impact on the population of these effluents requires the knowledge of several parameters, first of all the source term. To this aim, analytical algorithms are presented for evaluating the air activation in rooms hosting different types of modern accelerators, in particular an ion accelerator for radiotherapy, accelerators for fusion neutron sources and linear accelerators for radiotherapy (above 10 MV). A simplified model is used to assess the thermal neutron flux (mainly when a refined Monte Carlo model for calculations is not available), which is responsible for the production of airborne 41 Ar, the major concern for environmental contamination. The concentration of this contaminant in the bunker and the related release in the environment are evaluated considering a ventilation system that ensures a proper number of air changes. To verify compliance with the environmental standards, screening dose calculation factors from international reports are employed.

Thermal neutron detection plays a crucial role in numerous scientific and technical applications such as nuclear reactor physics, particle accelerators, radiotherapy, materials analysis and space exploration. There are several challenges associated with the accurate identification and quantification of thermal neutrons. The present work proposes a detailed characterization of a Timepix3 (TPX3) detector equipped with a Lithium Fluoride ( 6 LiF) converter in order to study its response to thermal neutrons that are identified through the 6 Li(n, α ) 3 H reaction. The TPX3-based test system has been installed at the HOTNES facility in ENEA and the analysis highlighted its excellent performance showing high effectiveness in the identification of neutrons through morphological analysis of tracks produced by alpha and triton particles, after accurate discrimination from the gamma background. With the use of Monte Carlo simulations, it has been demonstrated that the main contribution is due to tritons and its signal can be used effectively in the identification of thermal neutrons obtaining an efficiency of 0.9 % for 25 meV neutrons. This allows the TPX3 to have important applications as an environmental monitor for thermal neutrons. This monitoring system can be simply realized and is easy to manage because of its compact size and its digital acquisition that allows a real-time analysis.

ENEA is developing an accelerator-driven 14 MeV neutron source exploiting the deuterium–tritium fusion reaction to produce 99 Mo medical radioisotope as an alternative production route not based on fission reactors. It is expected that, during normal operation, a number of radionuclides, generated by means of neutron irradiation on the raw material (natural Molybdenum), will be produced and managed. The present manuscript, as foreseen by national law, discusses a hypothetical scenario to test the environmental screening models, in turn evaluating the mechanisms and parameters which affect and control the path of liquid effluents potentially released during normal operation of the facility. The aim is to estimate the amount of radioactivity to be operated and the fraction potentially discharged in this hypothetical scenario, so as to ensure that the radioactive material can be managed without any risk for the population and the environment, according to national regulations and thoroughly fulfilling the international guidelines.

The SORGENTINA-RF fusion source will rely on a metallic, water cooled rotating target and an ion source that will deliver a mixed deuteron-tritium (50-50) beam featuring 300 keV energy and about 830 mA current. The ion source will be firstly tested in hydrogen, thus delivering a 300-keV/830-mA proton beam onto a beam dump, to assess the beam performance. This paper describes the interaction of the proton beam with the residual gas that will be in the drift tube of the accelerator. The study relies on analytical calculations, which describe the different processes in details, and Monte Carlo simulations performed using GEANT4. The physical processes involved are described in detail. Moreover, the analytical and numerical calculations provide some figures on the bremsstrahlung radiation field produced by the secondary electrons generated by means of the proton-gas interactions and accelerated by the extraction grids of the ion source.

An analytical study, corroborated by Monte Carlo simulations, is presented which describes the interaction of a 300  keV–830 mA proton beam with a Cu and Al dumping system. The analytical calculations rely on the theoretical framework of the Particle Induced X-ray Emission, while the Monte Carlo simulations are performed by means of the GEANT4 toolkit. The case study is related to the project SORGENTINA-RF fusion neutron source and in particular to the tests devoted to assess the performance of the ion source of the plant. The results provide a detailed physical insight of the main processes occurring in the beam dump material, and are also important to give some realistic figures of the radiation emission expected during operation.

The SORGENTINA-RF project aims at designing and realizing an accelerator-driven 14 MeV fusion neutron source. The bio-shielding of this plant must guarantee a maximum contact dose rate of 10  μ Sv/h. For radiation protection purposes, baritic concrete is typically used in γ -ray sources. The higher density of the baritic concrete allows to obtain the same attenuation of the ordinary one, but over smaller thicknesses, albeit with higher production costs. In order to verify the effectiveness of the preliminary design of the SORGENTINA-RF neutron source relying on the use of both ordinary and baritic concrete layers, both neutron and γ -ray attenuation measurements were carried out. Neutron measurements were performed at the Frascati Neutron Generator (ENEA Frascati Research Center), while γ -rays measurements were carried out using the 60 Co source of the ENEA Bologna Research Center. The measurements were corroborated by Monte Carlo simulations performed by means of the MCNP6 code. The good agreement between experiments and simulations allowed to establish that the use of a layer of baritic concrete for the SORGENTINA-RF bio-shielding does not appear to be neither advantageous or cost-effective in terms of attenuation of the n/ γ radiation field, then suggesting the use of only ordinary concrete for the whole shielding design.

In the decommissioning of nuclear facilities, it is necessary to assess the radioactivity inventory for waste classification and management. For nuclear fusion experiments or accelerator-driven neutron sources, the main contribution to the radiological inventory comes from activation products and tritium. When water is used as coolant of components, it may be activated by neutrons with the consequent production of tritium, and short-lived oxygen and nitrogen isotopes. In most cases several chemical elements may be in solution or suspension in water, because of metallic pipes corrosion when occurring, or functional reasons, e.g. chemical conditioning, addition of antifreeze agent, etc. In this case other activation products could be present and need to be characterized. In this case study, a sample of the coolant of the ENEA Frascati Neutron Generator (FNG) has been radiologically, chemically and physically characterized. In such a facility, during the operation, a beam of deuterons is accelerated up to 300 keV and impacts on a tritiated target for producing 14 MeV neutrons exploiting the fusion reaction T(d,n)α. To avoid overheating in the area around the target, a water-cooling loop is used. After several years of operation, a sample of the fluid has been extracted to undergo a qualitative and quantitative analysis of the radionuclides inventory. Gamma spectrometry has not shown any presence of gamma emitters. On the other hand, Liquid Scintillation Counting (LSC) has provided evidence of the presence of beta emitters. It is known that tritium is expected to occur in the sample because of releases from the tritiated titanium target. This work concerns the development of a method to discriminate the tritium contribution with respect to the total beta activity within the FNG coolant. Since it is known that an unspecified percentage of an unknown anticorrosive agent was added to the water coolant, vacuum distillation has been used to extract purified water (containing only tritium) from the coolant sample leaving any (activated) non-volatile compound in the undistilled fraction. After distillation, any fraction has been investigated by Raman spectroscopy, to determine: a) the chemical composition of the colored anticorrosive agent, b) the efficiency of the separation. Afterwards, both fractions have been analysed by means of LSC, and results showed that the main contribution to sample activity is due to tritium and the activity values are consistent with the theoretical H atomic concentration in both fractions.

The SORGENTINA-RF fusion source will rely on a metallic, water cooled rotating target and an ion source that will deliver a mixed deuteron-tritium (50-50) beam featuring 300 keV energy and about 830 mA current. The ion source will be firstly tested in hydrogen, thus delivering a 300-keV/830-mA proton beam onto a beam dump, to assess the beam performance. This paper describes the interaction of the proton beam with the residual gas that will be in the drift tube of the accelerator. The study relies on analytical calculations, which describe the different processes in details, and Monte Carlo simulations performed using GEANT4. The physical processes involved are described in detail. Moreover, the analytical and numerical calculations provide some figures on the bremsstrahlung radiation field produced by the secondary electrons generated by means of the proton-gas interactions and accelerated by the extraction grids of the ion source.

. The impact of climate change is more and more burdensome, not only because extreme weather events are increasing in frequency and intensity, but also because the severity of the impact depends on the vulnerability of the system. In particular, radiological hazards due to extreme weather events and climate-related disasters in hospitals and in many industries should be considered and possibly implemented into risk management policies. In the present study, the impact of climate change on human activities involving ionizing radiations in Italy is analyzed. Therefore, different scenarios related to extreme weather events are taken into account, in particular the case of flooding, an increasingly frequent event in Europe in recent years and now recognized as one of the most dangerous disasters. Management of these risks means focusing on preparing for and responding to emergencies. To this scope, the vulnerability of the considered radiological practices is assessed and appropriate actions to be undertaken are proposed and evaluated in order to secure the site or implement adequate safety measures. These adaptation strategies are needed to address the impact of climate change and should be included in the safety and emergency plans, according to the principle of optimization of radiation protection.