This paper describes the performance of the LABDOS01, a silicon diode-based spectrometer suitable for dose measurements in mixed radiation fields. The instrument is currently being used in two high-altitude environmental dose monitoring projects: SAMADHA (South Atlantic Magnetic Anomaly Dosimetry at High Altitude) at Chacaltaya (Bolivia, 5240 m a.s.l.) and CORDIAL (COsmic Rays Dosimetry In Antarctic Latitudes) at the Concordia station (Antarctica, 3233 m a.s.l.). Before installing two of these devices at the measurement sites, the detectors were tested on flight routes covering a wide range of geomagnetic latitudes. The collected dosimetric data were compared with the expectations derived by the CARI-7A software, which provides the absorbed dose rate in silicon due to cosmic ray secondaries at a given position on the Earth. The measured dose rates along the flights at variable altitude and rigidity cutoff agree well with the simulated ones. By analyzing the spectrum of the energy deposited in the silicon layer, we derive an empirical method to approximately evaluate the ambient dose equivalent H^*(10), a quantity directly related to the biological damage caused by environmental radiation.

At the Testa Grigia high altitude research Station (3480 m. a.s.l, Italy, 4557' N, 742' E) several dosimetric campaigns for the measurement of the dose due to secondary neutrons produced in the atmosphere and in the surrounding environment by primary cosmic rays have been carried out from 2014 until 2021. Because of the high altitude of the site, the neutron flux at Testa Grigia is 10-15 times higher than at the sea level. Various instruments has been used to evaluate the dependence of the ambient dose equivalent rate from different factors as atmospheric parameters, environmental conditions and solar activity. Moreover, since October 2014 a modular neutron monitor designed, realized and tested by the SVIRCO Observatory Group INAF-IAPS in Rome, is permanently operating in the laboratory, providing a continuous monitoring of primary cosmic ray variability and making the laboratory an ideal place for dosimetric studies, instrument calibration and "in field " tests. In this paper the results of several neutron measurements carried out in the last years in periods of different solar activity and environmental conditions are reported, with a discussion on the origin of the observed variations of the ambient dose equivalent rate.

During the last two decades, major efforts were conducted to characterize the Cosmic-Ray induced neutron spectra in high-altitude stations under different geomagnetic/altitude conditions. Analyses proposed in this work are based on neutron spectra measurements (four stations: Chacaltaya Cosmic Ray Laboratory, Testa Grigia Research Station, Pic du Midi observatory and Concordia polar station) and transport simulations based on modelling of atmospheric cascades according to primary spectra which only depend on the solar modulation potential. Analyses focused on count rates, fluxes and neutron spectra. Complementary calculations allowed to deduce the solar potential and to assess the dose level. Trends of solar potential values issued from the neutron spectra are quite consistent. The monitoring of the neutron fluxes and the neutron dose rate show seasonal oscillations in the Pic du Midi while the Concordia was not impacted. Analyses show the interest to monitor continuously the neutron spectra in distributed high-altitude stations.

Because of the geomagnetic field shape, the polar regions are the most exposed to secondary particles and radiation produced by primary cosmic rays in the atmosphere. At present, only few experimental measurements of environmental dose are reported in literature at high southern latitudes. A three year campaign has been carried out in two different locations, Ushuaia (Argentina, 54.80∘ S, 68.30∘ W) and Marambio (Antarctica, 64.24∘ S, 56.63∘ W), using a Liulin type detector, allowing to measure the total environmental radiation flux and dose. The Liulin type instrument, measuring the energy deposition in a silicon detector, is especially suitable to evaluate the dose, separating the low and high LET (Linear Energy Transfer) components. The instrument was installed at the GAW Station in Ushuaia and inside the LAMBI Laboratory at the Marambio Antarctic base. In December 2017 preliminary measurements have been carried out at the French-Italian base Dome C, at 3233 m a.s.l., with a Liulin-AR, a new version of Liulin spectrometer, specifically built for this application by the Space Research and Technology Institute of Bulgarian Academy of Sciences. In this paper the environmental dose values obtained in the different southern high latitude locations are compared and discussed.

The preliminary results obtained in the first environmental radiation dosimetry campaign performed in the Antarctic region are presented. This experiment is carried out in the framework of CORA (COsmic Rays in Antarctica) Project, a collaboration between Argentine and Italian institutions. After a feasibility study performed in the Antarctic summer 2013, a new campaign has been carried out, started in March 2015, to measure various components of cosmic ray induced secondary atmospheric radiation at the Argentine Marambio Base (Antarctica; 196 m a.s.l., 64 degrees 13' 5, 56 degrees 43' W). Due to a very few dosimetric data available in literature at high southern latitudes, accurate measurements are performed by using a set of different active and passive detectors. Special attention is dedicated to measure the neutron ambient dose equivalent in different energy ranges, by using an active detector, the Atomtex Rem Counter, for neutron energy between 0.025 eV-14 MeV and a set of passive bubble dosimeters, sensitive to thermal neutrons and neutrons in the energy range 100 keV-20 MeV. The results obtained in the first six months of measurements for X and gamma radiation and for low and intermediate energy neutrons (E-n <= 20 MeV) are presented in this paper and show that at high latitude, also at sea level and at distance from the South Magnetic Pole, the ambient dose equivalent is significant, in particular for the high contribution of neutron component. This involves that at higher altitude (i.e. Antarctic Plateau, over 3000 m a.s.l.) the yearly ambient dose equivalent could be higher than the limit of 1 mSv recommended for general public by the International Commission on Radiological Protection (ICRP). (C) 2017 Elsevier Ltd. All rights reserved.

Aim: To employ the thermal neutron background that affects the patient during a traditional high-energy radiotherapy treatment for BNCT (Boron Neutron Capture Therapy) in order to enhance radiotherapy effectiveness.Background: Conventional high-energy (15-25 MV) linear accelerators (LINACs) for radiotherapy produce fast secondary neutrons in the gantry with a mean energy of about 1 MeV due to (gamma, n) reaction. This neutron flux, isotropically distributed, is considered as an unavoidable undesired dose during the treatment. Considering the moderating effect of human body, a thermal neutron fluence is localized in the tumour area: this neutron background could be employed for BNCT by previously administering B-10-Phenyl-Alanine ((10)BPA) to the patient.Materials and methods: Monte Carlo simulations (MCNP4B-GN code) were performed to estimate the total amount of neutrons outside and inside human body during a traditional X-ray radiotherapy treatment. Moreover, a simplified tissue equivalent anthropomorphic phantom was used together with bubble detectors for thermal and fast neutron to evaluate the moderation effect of human body.Results: Simulation and experimental results confirm the thermal neutron background during radiotherapy of 1.55E07cm(-2) Gy(-1). The BNCT equivalent dose delivered at 4 cm depth in phantom is 1.5 mGy-eq/Gy, that is about 3 Gy-eq (4% of X-rays dose) for a 70 Gy IMRT treatment.Conclusions: The thermal neutron component during a traditional high-energy radiotherapy treatment could produce a localized BNCT effect, with a localized therapeutic dose enhancement, corresponding to 4% or more of photon dose, following tumour characteristics. This BNCT additional dose could thus improve radiotherapy, acting as a localized radio-sensitizer. (C) 2015 Greater Poland Cancer Centre. Published by Elsevier Sp. z o.o. All rights reserved.

The paper is focused on the study of a novel photo-neutron source for BNCT preclinical research based on medical electron Linacs. Previous studies by the authors already demonstrated the possibility to obtain a mixed thermal and epithermal neutron flux of the order of 10(7) cm(-2) s(-1). This paper investigates possible Linac's modifications and a new photo-converter design to rise the neutron flux above 5 10(7) cm(-2) s(-1), also reducing the gamma contamination.

The paper proposes the study of a novel photo-neutron source based on a medical high-energy electron Linac. Previous studies by the authors already demonstrated the possibility to obtain with this technique a thermal neutron flux of the order of 10(7) cm(-2) s(-1). This paper shows possible Linac's setup and a new photo-converter design to reach a thermal neutron flux around 6 x 10(7) cm(-2) s(-1), keeping a reasonable high quality of the beam with respect to fast neutron and gamma contaminations.

HiDOSE (Heavy ion DOSimetry Experiment) and nDOSE (neutron DOSimetry Experiment) experiments conducted as a part of BIOKIS (Biokon in Space) payload were designed to measure the dose equivalent due to charged particles and to neutron field, on the entire energy range, during STS-134 mission. Given the complexity of the radiation field in space environment, dose measurements should be considered an asset of any space mission, and for this reason HiDOSE and nDOSE experiments represent an important contribution to the radiation environment assessment during this mission, a short duration flight. The results of these experiments, obtained using Thermo Luminescence Dosimeters (TLDs) to evaluate the charged particles dosimetry and neutron bubbles dosimeters and stack bismuth track dosimeters for neutron dosimetry, indicate that the dose equivalent rate due to space radiation exposure during the STS-134 mission is in accordance with the results obtained from long duration flights.

The use of neutrons as an investigative tool has received considerable attention over the last few years. Neutrons, due to their capability to penetrate thick layers of materials, are particularly suited to investigate inside or beneath the surface of an object without damaging it, determining structure at the microscopic scale, thus providing fundamental information. In particular, neutron measurements such as Neutron Diffraction (ND) or Neutron Tomography (NT), can study structural characteristics like composition, presence of alteration, inclusions, structure of the bulk, manufacturing techniques and presence of those elements which give us an overall fingerprint of the object’s characteristics. A neutron beam impinging onto any heterogeneous object is differently transmitted depending on neutron energy and on thickness, density, chemical composition and total cross section of the material along the line of sight. Recording the transmitted beam is possible to reconstruct the internal feature of the objects. Contrary to the photon case, a neutron beam can transmit through centimetres of metal but it is easily attenuated by small amounts of light elements like hydrogen, boron and lithium. The investigation of moisture and corrosion, the detection of explosives and adhesive connections and the inspection of defects in objects or in thick metallic samples are examples where neutron can be utilized favourably. For this reason neutron analysis is an unique tool for non-destructive testing with multidisciplinary applications. Furthermore, they can be used for physical problems such as residual stress measurements, study of mechanical behaviour in materials, archaeometry and cultural heritage. Introduction The use of neutrons to investigate the fundamental properties of materials began in the 1940s. The pioneering applications [1,2] were limited to studies of the physical properties of matter, and in particular to phase transitions, magnetic structures and especially the hydrogen bond. In the last three decades the use of neutrons has vastly expanded following the development of new technologies for the production of thermal and epithermal neutrons. Neutrons with wavelengths of the order of angstroms are able of probing molecular structures and find applications in a wide array of scientific fields, including biology, cultural heritage materials, environmental sciences, engineering, material sciences, mineralogy and solid state and soft matter physics (figure 1). Figure 1: neutrons for pure and applied science. The special nature of neutron interaction with matter provides important complementary and supplementary data to other techniques. The large penetration depth and selective absorption of neutrons make them a powerful tool in NDT (Non Destructive Testing) of materials. For example, the residual stress formed in a material during manufacturing, welding, utilization or repairs can be measured by means of neutron diffraction. In fact neutron diffraction is the only NDT method, which make possible a 3D mapping of residual stress in a bulk component. The experimental techniques are described in this paper. Neutron diffraction Neutron scattering is the most suitable method for resolving 3D samples and it mainly consists in Neutron Diffraction (ND). ND [3] is based on Bragg law 1 and allows to resolve matter crystallographic structures, determining the atomic and/or magnetic structure of a material. Moreover ND can be applied to study crystalline solids, gasses, liquids or amorphous materials. The method requires irradiating the analyzed sample with a collimated beam of low energy (cold or thermal) neutrons. The revealed intensity pattern gives information about the material structure. Neutron diffraction uses neutrons generated by fission or spallation. The first is mostly employed in steady-state nuclear reactors while the second usually in pulsed sources. In both cases the neutrons produced are moderated until to the thermal energy range, i.e. λ ≥ 0.05 nm. When a neutron beam of wavelength λ, comparable with the inter-planer spacing dhkl, impinges a crystalline material, a diffraction pattern is observed and the position of each plane (hkl) is obtained by the Bragg law:    hkl hkl d sin 2 Figure 2 shows 2θhkl angle related to Bragg peak and is linked to the direction of the incident 1 Bragg's law gives the angles for coherent and incoherent scattering from a crystal lattice. neutron beam. Thus, all dhkl are established from the angle θhkl at which the reflection is detected. Figure 2: Schematic illustration of Bragg scattering. Neutron diffractometers A polycrystalline sample consists of small (few μm) crystallites randomly oriented with respect to each other. When a monochromatic radiations strike a sample, the diffraction from a Bragg plane results in a cone shape, the Debye Scherrer cone, with semi-vortex angle 2θ. The intensity profile is recorded as a circle on a two dimensional detector (Figure 3). Figure 3: Diffraction from polycrystalline sample in a Debye Scherrer cone The polychromatic neutron beam is first monochromated to a chosen wavelength by diffraction from a suitable monochromator. The divergence and size of the monochromatic beam is suitably adjusted using appropriate neutron optical devices and is then diffracted from the specimen. In a similar way, the diffracted beam is shaped using suitable optical devices, before being captured by the neutron detector. The gauge volume over which the strain measurement is made is given by the intersection of the incident and diffracted beams (Figure 4). Strain measurement and determination The strain is measured towards the scattering vector, Q = kf ki, which splits the angle between incident and diffracted beams and is perpendicular to the diffracting planes, as shown in Figure 2. Lattice spacing is determined from the measured angular position of the diffraction peak (Bragg reflection) by irradiating the specimen with a monochromatic collimated neutron beam. If the specimen contains no strain, the lattice spacing is the strain free (stress free) values for the material and are denoted by d0,hkl. In a stressed specimen, lattice spacing is altered and a shift in each Bragg peak position occurs and the elastic strains then are given by:

Recent neutron emission detections have led to consider also the Earth's crust, in addition to cosmic rays, as a relevant source of neutron flux variations. Neutron emissions measured at seismic areas in the Pamir region (4200 m a.s.l.) exceeded the usual neutron background up to three orders of magnitude in correspondence to seismic activity and rather appreciable earthquakes, greater than or equal to the 4th degree in the Richter scale magnitude. The Authors present improved analysis with respect to that carried out by other research groups. The studies start from recent data acquired by Zanini et al. at the Testa Grigia Laboratory of Plateau Rosa, Cervinia, during an experimental campaign on the evaluation of neutron radiation from cosmic rays. Further data refer to a similar experimental campaign carried out in 1997 at Chacaltaya Laboratory in La Paz, Bolivia. The assessment of the neutron radiation at an environmental level could help to make a clear distinction between cosmic origin (cosmic rays) and the component from the Earth's crust (piezonuclear reactions). Moreover, taking into account the analogy between acoustic, electromagnetic emissions and seismic activity and also considering gas radon emission -that appears to be one of the most reliable seismic precursors- it will be possible to set up a sort of alarm systems that could be at the base of a regional warning network. This kind of warning system could combine the signals from other alarm stations to prevent the effects of seismic events and to identify the epicentre of an earthquake. Similar networks, only based on seismic accelerations, are being utilized all over the World in locations like Mexico, Taiwan, Turkey, Romania and Japan. Furthermore, neutron flux variations, in correspondence to seismic activity, may be an evidence of changes in the chemical composition of the crust, as a result of piezonuclear reactions.

In this paper we report about the BIOKIS payload: a multidisciplinary set of experiments and measurements in the fields of Biology (4) and Dosimetry (3) performed in microgravity. BIOKIS took advantage of the last STS-134 Endeavour mission and engineering state of the art in Space Life Science. The BIOKIS payload is compact, efficient, and capable to host experiments with different samples and science disciplines. Moreover, the time overlap of biological experiments and dosimetry measurements will produce more insightful information.

Because of the increasing in space mission duration and number of space travellers the requirement of an accurate assessment of space radiation damage and the evaluation of suitable shielding is a crucial necessity.In particular it is unavoidable in planning future missions to the Moon and Mars.In this paper the method for the evaluation of the cosmic radiation dose on board of spacecraft is described.As an example experimental measurements and MonteCarlo calculation of the contribution of various components of secondary radiation inside the FOTON-M3 ESA Satellite are described, with special attention to the neutron component.

The absorbed dose in BNCT (boron neutron capture therapy) consists of several radiation components with different physical properties and biological effectiveness. In order to assess the clinical efficacy of the beams, determining the dose profiles in tissues, Monte Carlo (MC) simulations are used. This paper presents a comparison between dose profiles calculated in different phantoms using two techniques: MC radiation transport code, MCNP-4C2 and BNCT MC treatment planning program, SERA (simulation environment for radiotherapy application). In this study MCNP is used as a reference tool. A preliminary test of SERA is performed using six monodirectional and monoenergetic beams directed onto a simple water phantom. In order to deeply investigate the effect of the different cross-section libraries and of the dose calculation methodology, monoenergetic and monodirectional beams directed toward a standard Snyder phantom are simulated. Neutron attenuation curves and dose profiles are calculated with both codes and the results are compared.

Radiation assessment and protection in space is the first step in planning future missions to the Moon and Mars, where mission and number of space travelers will increase and the protection of the geomagnetic shielding against the cosmic radiation will be absent. In this framework, the shielding effectiveness of two flexible materials, Kevlar and Nextel, were tested, which are largely used in the construction of spacecrafts. Accelerator-based tests clearly demonstrated that Kevlar is an excellent shield for heavy ions, close to polyethylene, whereas Nextel shows poor shielding characteristics. Measurements on flight performed onboard of the International Space Station and of the Foton-M3 capsule have been carried out with special attention to the neutron component; shielded and unshielded detectors (thermoluminescence dosemeters, bubble detectors) were exposed to a real radiation environment to test the shielding properties of the materials under study. The results indicate no significant effects of shielding, suggesting that thin shields in low-Earth Orbit have little effect on absorbed dose.

Boron Neutron Capture Therapy (BNCT) is a radiotherapic technique still under development that could become crucial in the fight against some types of cancer (extended ones, located near vital organs or radioresistant). This binary technique requires the administration to the patient of a boron delivery agent and the irradiation with a thermal neutron beam. The high LET particles produced in the B-10(n, alpha)Li-7 reaction are exploited to destroy the tumour cells. This work presents a new system based on neutron autoradiography with a non-depleted self-triggering microstrip silicon detector, using a neutron beam produced by a hospital Linac. The system is fast, real time and allows the detection of B-10 contents down to 25 ng. The main results on the study of B-10 uptake in biological samples will be described in terms of kinetic curves (B-10 uptake as a function of time).