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It is of the utmost importance to know the water content in a soil, or soil moisture, for its role in triggering destructive events. In recent years, soil moisture has been recognized as a key information to improve wildfire predictions, proving more reliable than predictions based on weather data. Accumulation of water in slopes can reduce cohesion and friction thus triggering landslides and mudslides, while indeed the water quantity in the form of snow (SWE – Snow Water Equivalent) is responsible for avalanches. Cosmic Ray Neutron Sensing (CRNS) technology provides unique capabilities to determine water content in soil, snow, and biomass by filling the gap left by current methods in term of scale and depth. A single, autonomous probe placed over the ground, requiring little maintenance, is able to provide real-time data on a large scale (hectares), in deep (tens of cm in soil, meters in snow). The new generation of CRNS probes allows the contextual detection of muons, which provides detailed information about variations of the local flux of incoming cosmic rays. Previous probes rely on a public network of reference stations to monitor flux variations, with the closest station possibly being hundreds of km away from the site and the data availability being reliant on an external entity. On situ monitoring of the incoming flux is therefore a key improvement of the method reliability. In 2022 ANAS, the Italian company responsible for road infrastructures, funded a Proof-of-concept project called MY-LAND, with the aim of verifying on field the capability of CRNS probes to support risk assessment. In the framework of this project, FINAPP installed two CRNS probes for large-scale soil moisture measurement along the Longarone - Belluno Smart Road, obtaining data that were used together with hydrological models of the area to assess the risk of landslides or flash floods. The first probe was installed in Acquabona (Cortina d’Ampezzo), where a high risk of debris flows is expected, and the second in Perarolo di Cadore, where a landslide is considered a threat to the town. Two significant landslide events were observed in the sites during the experiment. Results show how CRNS technology, when supported by the knowledge of specific hydrological models of the land and weather forecast, is able to provide a valuable contribution to risk assessments and decisional processes.

Secondary cosmic-ray neutrons may be effectively used as a proxy for environmental hydrogen content at the hectare scale. These neutrons are generated mostly in the upper layers of the atmosphere within particle showers induced by galactic cosmic rays and other secondary particles. Below 15 km altitude their intensity declines as primary cosmic rays become less abundant and the generated neutrons are attenuated by the atmospheric air. At the earth surface, the intensity of secondary cosmic-ray neutrons heavily depends on their attenuation within the atmosphere, i.e. the amount of air the neutrons and their precursors pass through. Local atmospheric pressure measurements present an effective means to account for the varying neutron attenuation potential of the atmospheric air column above the neutron sensor. Pressure variations possess the second largest impact on the above-ground epithermal neutron intensity. Thus, using epithermal neutrons to infer environmental hydrogen content requires precise knowledge on how to correct for atmospheric pressure changes.We conducted several short-term field experiments in saturated environments and at different altitudes, i.e. different pressure states to observe the neutron intensity pressure relation over a wide range of pressure values. Moreover, we used long-term measurements above glaciers in order to monitor the local dependence of neutron intensities and pressure in a pressure range typically found in Cosmic-Ray Neutron Sensing. The results are presented along with a broad Monte Carlo simulation campaign using MCNP 6. In these simulations, primary cosmic rays are released above the earth atmosphere at different cut-off rigidities capturing the whole evolution of cosmic-ray neutrons from generation to attenuation and annihilation. The simulated and experimentally derived pressure relation of cosmic-ray neutrons is compared to those of similar studies and assessed in the light of an appropriate atmospheric pressure correction for Cosmic-Ray Neutron Sensing.

The constant concerns in global nuclear safety, aimed at deterring and combating the illicit trafficking of Material Out of Regulatory Control (MORC) and its possible use in criminal acts has raised the necessity of new detection solutions with higher efficiency and resolution to provide a high level of accuracy in the report to the authorities. Today’s radioactive isotope identifiers perform gamma spectroscopy identification and, sometimes, neutron counting. This paper presents the results of measurements performed in real-scenario conditions with a new type of portable radioactive isotope identifier for the detection and identification of both gamma and neutron sources. Its singular features are: 1) the capability to identify sources through the detection of neutrons, discriminating spontaneous fission sources (Cf-252), α-n sources (Am/Be, Am/Li) and nuclear material containing mix of isotopes of plutonium or uranium 2) the capability to make cross correlation between gamma and neutron measurements to achieve a higher level of accuracy in the identification of SNM that emits both neutrons and characteristics gammas. The test results are compared with international standards. The device exceeds the standard performance by triggering a neutron alarm for a 20.000 n/s Cf-252 source at a five times greater distance than the ANSI N42.34 one.

In the last decade the measurement of secondary cosmic ray neutrons has been established as a unique approach for intermediate scale observation of land surface hydrogen pools. Originally developed for soil moisture measurements, it has shown also promising applications for snow, biomass and canopy interception. The approach relies on the correlation between natural neutron background as created by cosmic-ray fluxes and local hydrogen pools. Due to the specific capabilities of the neutrons to move in air, the signal detected by the sensor installed above-ground is sensitive to an area of hundreds of meters providing a new perspective for proximal land-surface observations. The measurements are generally performed based on moderated proportional counters filled with Helium-3 or Boron and the moderation is created by adding shielding material (mostly polyethylene) around the counter.The signal is affected by the temporal variability of the incoming neutron fluxes. At first, the variability of neutron fluxes is due to solar activities. The neutrons are further attenuated by the mass of the air and air humidity.Specific corrections have been proposed to account for these effects. Air pressure and humidity corrections rely on local measurements that could be easily collected. Incoming correction due to solar cosmic-ray fluctuation is based on a worldwide network monitoring station (NMDB). This network provides online access to their data in real-time. However, this approach showed some limitations in region where incoming fluxes could be not representative of local conditions introducing errors that could be relevant for the estimation of the targeted variable. In addition, it requires the need of post-processing of the data resulting in some difficulties to provide, e.g., soil moisture observations in real-time.In the present contribution, we show the results of tests conducted on an alternative commercial sensor based on scintillators. The new probe has the capability to identify different neutron energies ranges and gamma-rays providing new opportunities for hydrological observations at different spatial scales. In addition, the probe is sensitive to high energy particles that can be used for correcting the neutron signal by the variations of primary cosmic-ray flux. We present results from the comparison of the new probe with standard proportional counters and neutron monitor database in a long-term outdoor case study. We show how the use of local high energy particles is a practical alternative to account atmospheric corrections and overcome the limitation of using data from NMDB.

Signal digitizers revolutionized the approach to the electronics readout of radiation detectors in Nuclear Physics. These highly specialized pieces of equipment are designed to acquire the signals that are characteristic of the detectors in nuclear physics experiments. The functions of the several modules that were once needed for signal acquisition, can now be substituted by a single digitizer. As suggested by the name, with such readout modules, signals are first digitized (i.e. the signal waveform is sampled and converted to a digital representation) and then either stored or analyzed on-the-fly. The performances can be comparable or better than the traditional analog counterparts, in terms of energy, time resolution, and acquisition rate. In this work, we investigate the use of general-purpose digital oscilloscopes as signal digitizers for nuclear detectors. In order to have a proper comparison, we employ a distributed data acquisition system (DAQ), that standardizes the interface between the hardware and the on-line data analysis. The signals, from a set of typical radiation detectors, are digitized and analyzed with the very same algorithms in order to avoid biases due to different software analysis. We compare two traditional signal digitizers (CAEN DT5725 and CAEN DT5751) to two low-cost digital oscilloscopes (Digilent Analog Discovery 2, and Red Pitaya STEMLab 125-14), in terms of their capabilities for spectroscopy (energy resolution), time resolution, pulse shape discrimination, and maximum acquisition rate., Comment: 17 pages, 8 figures, 4 tables, Prepared for submission to JINST

Cosmic-ray neutron sensing (CRNS) has been established as a reliable method to estimate non-invasively field average soil moisture. Most of the detectors are, however, based on expensive or toxic materials providing some limitations for a wider application of the method. In this study we further test and develop a new neutron detector based on composite scintillators specifically designed for agro-hydrological applications called CRNS-Finapp. It is shown that the probe is very sensitive to the temperature, however, the effect can be easily compensated by the high voltage module embedded in the probe. Field experiments conducted at a vineyard also support the capability of this new detector to be integrated in long-term observation networks. Further developments will focus on improving the efficiency of the neutron counting rate, on the reduction of the power consumption and on the communication protocols for the transmission of the data.

A large area low-cost detector for detailed studies of ortho-Positronium formation and decay is being designed. The detector will be made of four modules each consisting of a thin slab of YAP(Ce) scintillator read out by a multi-anode flat panel photomultiplier tube. The proposed configuration will provide a position sensitive detector capable of recording, on an event-by-event basis, both the 2 γ and the 3 γ decay channels, for immediate information on the 2 γ /3 γ ratio. It will as well provide a 3D density distribution of the decay vertexes, thus enabling angular and velocity distribution measurements. In this paper we present the results of measurements performed on one module of the detector using conventional electronics, as well as Monte Carlo simulations on the performances of the system. Using a series of laboratory gamma sources we deduced values of energy and spatial resolution.

The detection of thermal neutrons is increasingly important for several fields of interest, so new versatile, manageable and adaptable detectors are needed for applications in different environments and situations. To date, scintillators for thermal neutrons available on the market are fragile and with low adaptability. In this work, flexible and robust thermal neutron scintillators with improved properties as compared to commercial ZnS:Ag based phosphors are produced. The scintillators are produced by mixing ZnS:Ag powder and 6LiF nano-crystals in polysiloxane binders. 6LiF nano-crystals are synthesized by co-precipitation method, and the detection efficiency is optimized by tuning the crystal size through different solvent/co-solvent ratios. Then, the detection yield to thermal neutrons is investigated as related both to the crystal size and to the binder. Two different siloxanes, either with pendant phenyl groups or with aliphatic groups are used, the former being intrinsically fluorescent and with higher polarizability than the latter. The response to γ -rays is also evaluated. Lastly, the right combination of base resin and 6LiF crystals size allows to produce flexible scintillators for thermal neutrons with performances comparable to the commercial standard and with higher mechanical robustness and stability.

The European H2020 project entitled “effective container inspection at border control point” (C-BORD) focuses on the development and in-situ tests of a comprehensive, cost-effective solution for the generalized non-intrusive inspection (NII) of containers and large-volume freight at the European Union border. The opening procedures of suspect containers are time consuming and expensive for economical and safety reasons; therefore, to reduce such operations, the C-BORD project aims to develop a set of technologies that can improve the quality of NII. Among these techniques, a tagged neutron inspection system is being developed in the C-BORD project. It will be a second-line defense system, to be used on sealed containers to detect explosives, illicit drugs, and chemical agents in suspect voxels (elementary volume units). This method employs a beam of tagged neutrons and a set of NaI(Tl) and LaBr[Formula: see text](Ce) scintillators, which will be used to detect prompt gamma rays produced by the neutron interactions. Here we report the advances on the development of the C-BORD’s rapidly relocatable tagged neutron inspection system, in particular the comprehensive characterization of the NaI(Tl) and LaBr[Formula: see text](Ce) gamma detectors (time and energy resolutions, high-count-rate behavior), the digital analysis for time-coincidence measurements and the data acquisition system (DAQ).

A new sensor for alpha particles based on plastic scintillators immersed in water was demonstrated to provide a viable solution for real-time detection of radioactive contaminants in water. It is obtained by stacking an array of plastic modules composed by a thin layer of Ag-doped zinc sulphide , ZnS(Ag), deposited on a plastic scintillator foil. Alpha particles are detected in the ZnS(Ag) layer, whereas beta are detected inside the plastic substrate. One still unexplored aspect of this novel detection technology is how the long-term contact with water affects the detector performance. To protect its surface from water-induced damages, we identified a coating protocol based on a poly(methyl-methacrylate) film deposited by spraying on the ZnS(Ag) active layer of the scintillator. The ageing process of the scintillator was carried out by using suitable aqueous solutions and the effect on the sensing layer was monitored by measuring its wettability and surface morphology. The performance of the coated scintillator was tested by measuring the efficiency with alpha radioactive sources.

In this article we present a distributed Data Acquisition (DAQ) system developed for the C-BORD project [1], [2]. Many examples of DAQ systems are monolithic processes that run on a computer attached to the DAQ hardware. In this new DAQ, a different process is assigned to each task of the system (e.g. data acquisition, pre-processing, analysis, high-voltage management...). The communication between the processes is obtained through dedicated communication sockets. An important advantage of this approach is the possibility to distribute the system over several computers connected in a network, in order to distribute the computational load. The distributed nature of the system allows also the implementation of on-line data analysis processes that can be computationally intensive. Moreover the system is very versatile, as the different tasks can be dynamically activated or disabled, and robust, since a failure of one of the processes does not jeopardize the whole system. The system has been used in the project to acquire the data generated by fast signal digitizers. Excellent results were obtained, both in terms of performance (e.g. maximum acquisition rates) and stability. The project entitled “effective Container inspection at BORDer control points” (C-BORD) is funded by the European H2020 program. Its aim is to develop a comprehensive set of technologies for the generalized Non-Intrusive Inspection (NII) of containers and large-volume freight at the EU border.

International audience; The European project entitled "effective Container inspection at BORDer control points" (C-BORD) focuses on the development and in-situ tests of a comprehensive cost-effective solution for the generalized Non-Intrusive Inspection (NII) of containers and large-volume freight at the European Union (EU) border. It copes with a large range of targets, including explosives, chemical warfare agents, illicit drugs, tobacco and Special Nuclear Materials. Within the C-BORD project, a new generation of Tagged Neutron Inspection System (TNIS) for cargo containers is foreseen. Unlike its predecessors, this system would be the first Rapidly Relocatable TNIS (RRTNIS). It will be a second-line defense system, to be used on sealed containers in order to detect explosives, illicit drugs and chemical agents in a suspect voxel (elementary volume unit). We report on the status of the RRTNIS system, in particular the overall design, the characterization of the large-volume NaI(Tl) gamma detectors, the digital analysis of the time measurements and the Data Acquisition System (DAQ).

A compact and modern equipment for implementing the fast neutron and γ-ray transmission technique (FNGT) has been developed in order to estimate the sulphur content of crude oil. FNGT is employed for non- destructive analysis of different kinds of samples. The compact system presented in this work represents an improvement of our previous experimental set-up [1, 2]. It makes use of a 252Cf source, an EJ-301 liquid scintillator detector (2″ × 2″) with excellent n/γ discrimination capabilities, and modern nuclear electronics based on fast digitizers. The fast neutron and gamma transmission technique was employed to study a system for on-line sulphur concentration measurement in Venezuelan heavy sour oil. The range of sulphur concentrations investigated is between 0.1 and 6.5 wt%. The equipment performances and limitations are compared with those predicted by a Monte Carlo model built in GEANT4 v10.01. The results show the possibility to implement a compact unit for on-line determination of sulphur concentration in crude oil.

Thanks to its advanced system for the control of magnetohydrodynamic modes, the RFX-mod device run as a tokamak is particularly suited to the study of the possible impact on runaway electron (RE) de-confinement in response to applied magnetic perturbations. This paper shows that during the flat-top phase in RFX-mod discharges, with a plasma current of I p ∼ 150 kA and a low density ( n e < 10 19 m−3), the amount of REs scales with the m = 2,n = 1 perturbation both in q(a) q(a) > 2 plasmas. Similar results have also been obtained in post-disruption phases, but still with limited statistics. The mechanisms generating REs and the effect of magnetic perturbation (MP) on their confinement are interpreted by numerical simulations with the relativistic guiding center code ORBIT. The role played by different magnetic equilibria on the energy of REs and on their loss rates is investigated. ORBIT simulations indicate that RE-enhanced losses are associated with a raised level of stochasticity, the effect being more pronounced when the MP amplitude is higher and internally resonant.

This paper describes a distributed Data Acquisition System (DAQ) developed for the TAWARA_RTM project (TAp WAter RAdioactivity Real Time Monitor). The aim is detecting the presence of radioactive contaminants in drinking water; in order to prevent deliberate or accidental threats. Employing a set of detectors, it is possible to detect alpha, beta and gamma radiations, from emitters dissolved in water. The Sensor Network (SN) consists of several heterogeneous nodes controlled by a centralized server. The SN cyber-security is guaranteed in order to protect it from external intrusions and malicious acts. The nodes were installed in different locations, along the water treatment processes, in the waterworks plant supplying the aqueduct of Warsaw, Poland. Embedded computers control the simpler nodes, and are directly connected to the SN. Local-PCs (LPCs) control the more complex nodes that consist signal digitizers acquiring data from several detectors. The DAQ in the LPC is split in several processes communicating with sockets in a local sub-network. Each process is dedicated to a very simple task (e.g. data acquisition, data analysis, hydraulics management) in order to have a flexible and fault-tolerant system. The main SN and the local DAQ networks are separated by data routers to ensure the cyber-security.

A commercial boron-loaded liquid scintillator EJ-339 A was studied, using a 252Cf source with/without polyethylene moderator, to examine the possibility of discriminating slow-neutron induced events in 10B from fast-neutron events, resulting from proton recoils, and gamma-ray events. Despite the strong light quenching associated with neutron induced events in 10B, correct classification of these events is shown to be possible with the aid of digital signal processing.

The light output response and the neutron and gamma-ray detection efficiency are determined for liquid scintillator EJ-309. The light output function is compared to those of previous studies. Experimental efficiency results are compared to predictions from GEANT4, MCNPX and PENELOPE Monte Carlo simulations. The differences associated with the use of different light output functions are discussed.

We have studied the prototype of a new plastic scintillator material (EJ-299-33) engineered for gamma-neutron discrimination. Energy and time resolutions as well as pulse shape discrimination capability have been compared with those of standard plastic and liquid scintillators. EJ-299-33 characteristics are somewhat poorer compared to standard scintillators. However, results obtained with the new plastic material suggest its possible use in basic research (time-of-flight measurements) as well as in Homeland Security applications (neutron/gamma monitoring device).

The pulse shape discrimination (PSD) between neutrons and gamma rays in liquid scintillators is studied by using the charge integration method with fast digitizers having different technical characteristics. The use of the Figure of Merit (FoM) to verify the PSD capability is discussed. The dependence of the FoM on the digitizer sampling rate and resolution is experimentally determined. The effects due to the type of source and the irradiation geometry are also evidenced and discussed.

A correct soil moisture estimation is a fundamental prerequisite for many applications: agriculture, meteorological forecast, flood and drought prediction, and, in general, water accounting and management. Traditional methods typically provide point-like measurements, but suffer from soil heterogeneity, which can produce significant misinterpretation of the hydrological scenarios. In the last decade, cosmic-ray neutron sensing (CRNS) has emerged as a promising approach for the detection of soil moisture content. CRNS can average soil moisture over a large volume (up to tens of hectares) of terrain with only one probe, thus overcoming limitations arising from the heterogeneity of the soil. The present paper introduces the development of a new CRNS instrument designed for agricultural applications and based on an innovative neutron detector. The new instrument was applied and tested in two experimental fields located in Potsdam (DE, Germany) and Lagosanto (IT, Italy). The results highlight how the new detector could be a valid alternative and robust solution for the application of the CRNS technique for soil moisture measurements in agriculture.

A compact neutron/gamma detector has been developed using a liquid scintillator cell coupled to a Flat Panel PMT; performances have been compared with a second cell coupled to a traditional linearly-focused 12 dynodes PMT. Energy resolution and pulse shape discrimination (PSD) measured by using a fast digitizer are very similar for the two detectors with the time resolution of the Flat Panel PMT slightly worse. The new detector results to be weakly affected by the influence of a moderate magnetic field while the traditional PMT exhibits strong pulse reduction. The compact size and the low power consumption obtained by using the Flat Panel PMT are very useful in portable neutron/gamma spectrometers.

Characterization and calibration measurements were carried out at the National Institute of Ionizing Radiation Metrology of ENEA on the TAp WAter RAdioactivity (TAWARA) Real Time Monitor system recently developed for real time monitoring of radioactive contamination in water processed at water treatment facilities. Reference radiations and radionuclides were chosen in order to reflect energy ranges and radiation types of the major water radioactive contaminants possibly arising from environmental, industrial or terroristic origin. The following instrument parameters were tested: sensitivity, selectivity, background, short/long term stability, linearity with respect to activity.

A new composite detector has been developed by combining two different commercial scintillators. The device has the capability to detect gamma rays as well as thermal and fast neutrons; the signal discrimination between the three types is performed on-line by means of waveform digitizers and PSD algorithms. This work describes the assembled detector and its discrimination performance to be employed in the applied field.

MODES_SNM project aimed at developing a mobile/portable modular detection system for radioactive sources and Special Nuclear Material (SNM). Its main goal was to deliver a tested prototype capable of passively detecting weak or shielded radioactive sources with accuracy higher than that of currently available systems. By the end of the project all the objectives have been successfully achieved. Results from the laboratory commissioning and the field tests are presented in this publication.

The light output of neutron detectors based on the plastic scintillator EJ228 is studied as a function of neutron energy using a time tagged 252Cf source. Calibration of the light output scale is performed by fitting the experimental distribution of Compton scattering events of photons from a 22Na source with a response function obtained by Gaussian smearing of the predicted line-shape. The light output curve as well as the pulse height resolution for the EJ228 scintillators is very close (within 5%) to those recently reported for NE213 type organic liquid scintillators.

Nowadays, many examples of data acquisition (DAQ) software for experimental nuclear physics are monolithic processes that run on a computer attached to the DAQ hardware. In this article we present a distributed DAQ system developed for the C-BORD project. With our system, we propose a novel approach, in which each task related to the different DAQ parts (acquisition, pre-process, analysis, etc.) runs in a separate process. In particular, the system is composed of a set of servers that exchange information through dedicated communication sockets. Therefore, with this architecture, an important advantage is the possibility to run the processes on different computers to distribute the computational load. The initial tests of the system have been giving excellent results, both in terms of performance (i.e., maximum acquisition rates) and stability. The project entitled “Effective container inspection at BORDer control points” (C-BORD) is funded by the European H2020 programme. Its aim is to develop a comprehensive set of technologies for the generalized non-intrusive inspection (NII) of containers and large-volume freight at the European Union border.

The performance of a spectrometry system (SPEC) for identification of trace activities in water is presented. The SPEC detector is a part of the TAWARA_RTM platform designed for monitoring of water processed for distribution by the Waterworks Company. The SPEC system is dedicated for identification of radioisotopes emitting γ-rays of energies between 50 keV and 2 MeV. The SPEC detector comprises a CeBr 3 scintillator grown from specially purified raw material with reduced content of actinides that produce unwanted alpha particle background. In order to reduce the Compton scattering background, an active anti-Compton shield (ACS) made of BGO is used. In addition, a passive lead shield around the ACS is used for further suppression of the external background. The SPEC detector is designed for use with a dedicated concentrator system, that will be used for absorption of a selected group of radioactive elements that may be present in water processed at the waterworks. The system is tested upon capability to detect the γ-ray emitters with activity according to the guidance levels published by the EU in the Council Directive.

The neutron and gamma responses of a commercial 6Li loaded ZnS(Ag) detector (EJ-420) have been studied using a moderated 252Cf source and a set of pure gamma ray sources (137Cs and 241Am). Digital pulse processing was used to implement the pulse shape discrimination technique in order to well-separate neutrons from gamma-induced events. It was found that in case of a mixed neutron/gamma radiation field (252Cf) pulse-height discrimination technique works quite good for the measurement of the neutron field, but if one desires to reach a gamma-to-neutron sensitivity ratio lower than 0.7% pulse shape discrimination technique must be implemented. The decay time of the scintillation components of ZnS(Ag)/6LiF were determined by following the so called ``peeling off method''. The results were compared with some reported values. In order to better understand the shape of the neutron-induced pulses produced by the EJ-420 detector, a measurement with an EJ-440 detector of an alpha source (210Po) was performed. The response of both detectors must be very similar because these are based in ZnS(Ag) scintillator. It seems that for neutron detection with the EJ-420, the slow component of the scintillation yield produced by the tritium is higher than the one produced by the alpha particle. Finally, the neutron efficiency and some experimental features of the EJ-420 detector were determined and reproduced respectively by Monte Carlo simulations (GEANT4 9.6).

This paper reports the main recent results of the RFX-mod fusion science activity. The RFX-mod device is characterized by a unique flexibility in terms of accessible magnetic configurations. Axisymmetric and helically shaped reversed-field pinch equilibria have been studied, along with tokamak plasmas in a wide range of q(a) regimes (spanning from 4 down to 1.2 values). The full range of magnetic configurations in between the two, the so-called ultra-low q ones, has been explored, with the aim of studying specific physical issues common to all equilibria, such as, for example, the density limit phenomenon. The powerful RFX-mod feedback control system has been exploited for MHD control, which allowed us to extend the range of experimental parameters, as well as to induce specific magnetic perturbations for the study of 3D effects. In particular, transport, edge and isotope effects in 3D equilibria have been investigated, along with runaway mitigations through induced magnetic perturbations. The first transitions to an improved confinement scenario in circular and D-shaped tokamak plasmas have been obtained thanks to an active modification of the edge electric field through a polarized electrode. The experiments are supported by intense modeling with 3D MHD, gyrokinetic, guiding center and transport codes. Proposed modifications to the RFX-mod device, which will enable further contributions to the solution of key issues in the roadmap to ITER and DEMO, are also briefly presented. © 2017 IAEA, Vienna.

In this paper, we shall present a simple VME front-end system that employs the FADC CAEN V1720 8- channel 12-bit 250-MS/s digitizer. This system produces coincidence spectra between the trigger particle and other detectors and it replaces the traditional technique of chaining analog electronics. Tests have been performed using a pulser working at different frequencies as well as employing a 252Cf source in concert with an array of detectors.

The capability of liquid scintillator (namely 2" × 2" cells of EJ301 and EJ309) of detecting neutrons in a very high gamma ray background is explored. A weak 252Cf source has been detected in a high 137Cs gamma ray background corresponding to a dose rate of 100 μSv/h with probability of detection in compliance with IEC requirements for hand held instruments. Tests were performed with new generation of CAEN digitizers, in particular the V1720 (8 Channel 12bit 250 MS/s) one.

An integrated mobile system for port security is presented. The system is designed to perform active investigations by using the tagged neutron inspection technique of suspect dangerous materials as well as passive measurements of neutrons and gamma rays to search and identify radioactive and special nuclear materials. The system has been employed in detection tests of special nuclear material as well as in a seaport demonstration.

A new laboratory facility for non-destructive analysis (NDA) using a time-tagged (252)Cf source is presented. The system is designed to analyze samples having maximum size of about 20 × 25 cm(2), the material recognition being obtained by measuring simultaneously total and energy dependent transmission of neutrons and gamma rays. The equipment technical characteristics and performances of the NDA system are presented, exploring also limits due to the sample thickness. Some recent applications in the field of cultural heritage are presented.

In this work we present the characterization of a large area $200~\hbox{mm} \times 200~\hbox{mm}$ EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests were performed in order to determine the best setup to read-out the light from the detector side. The possibility to stack many detectors and get a compact device with total active area of the order of $1~\hbox{m}^2$ has been explored. Alpha/beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-time monitoring in drinking water is a goal of the EU project TAWARA_RTM.

The energy resolution of a LaBr(Ce) detector has been studied as a function of the count rate up to 340 kHz by using a 12bit 250 MS/s V1720 digitizer. The time resolution achieved by processing off line the digitized signals has been also determined. When results are compared with the ones obtained by using standard NIM electronics, it appears that the energy resolution obtained with the V1720 digitizer is better than the one with the NIM standard whereas the time resolution is poorer. However the time resolution by using the V1720 digitizer of about 1.2 ns [FWHM] seems to be sufficient for applications in Non-Destructive Analysis of large objects with tagged neutron beams.

The detection of special nuclear material has been studied with a mobile inspection system used both as a high sensitivity passive neutron/gamma spectroscopic tool and as an active inspection device using tagged neutrons. The detection of plutonium samples seems to be possible with passive interrogation, even for small samples, thanks to the yield of gamma ray and neutrons. Moreover the gamma ray spectrum shows clear signatures related to 239Pu. The passive detection of uranium is much more difficult because of the low neutron yield and of the easiness of shielding the gamma ray yield of highly enriched U samples. However, we show that active interrogation with tagged neutrons is able to provide signatures for the discrimination of uranium against other heavy metals.

The detection of special nuclear material has been studied with the SMANDRA mobile inspection system used both as a high sensitivity passive neutron/gamma spectroscopic tool and as an active inspection device using tagged neutrons. The detection of plutonium samples is possible with passive interrogation, the passive detection of uranium being much more difficult because of the low neutron yield and of the easiness of shielding the gamma rays. However, we show that active interrogation with tagged neutrons is able to provide signatures for the discrimination of uranium against other materials.

Using a fast digitizer, the neutron–gamma discrimination capability of the new liquid scintillator EJ-309 is compared with that obtained using standard EJ-301. Moreover the capability of both the scintillation detectors to identify a weak neutron source in a high gamma-ray background is demonstrated. The probability of neutron detection is PD =95% at 95% confidence level for a gamma-ray background corresponding to a dose rate of 100 μSv/h.

The energy resolution of a LaBr(Ce) detector has been studied as a function of the count rate up to 340 kHz by using a 12 bit 250 MS/s V1720 digitizer. The time resolution achieved by processing off line the digitized signals has been also determined. It appears that the energy resolution obtained with the digitizer is better than that achievable using standard NIM electronics. The time resolution yielded by the digitizer with a software CFTD is about δt=0.8 ns (FWHM), slightly worse with respect to δt=0.65 ns (FWHM) obtained from standard NIM. However, this time resolution lies well within the requirements for applications in Non-Destructive Analysis of large objects with tagged neutron beams.

An integrated mobile system for port security is presented. The system is designed to perform active investigations, by using the tagged neutron inspection technique, of suspect dangerous materials as well as passive measurements of neutrons and gamma rays to search and identify radioactive and special nuclear materials.

Material recognition is studied by measuring simultaneously the transmission of neutron and gamma rays produced by a time-tagged 252Cf source. Light elements (C,N,O) are identified by using the measured transmission versus neutron time of flight. The yield of the transmitted gamma ray as a function of energy provides high precision identification of the atomic number of the sample up to Z=83 . A tomography system, currently under construction, is described.

Material recognition is studied by measuring simultaneously the transmission of neutron and gamma rays produced by a time-tagged 252Cf source. The possibility to derive direct signatures to identify light elements (C,N,O) by using the measured transmission versus neutron time of flight is demonstrated. The yield of the transmitted gamma ray as a function of energy in the range 0.1–5.5 MeV provides high precision identification of the atomic number of the sample. A tomography system, currently under construction, is described.