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Neutron inspection of sea-going cargo containers has been widely studied in the past 20 yr to non-intrusively detect terrorist threats, like explosives or Special Nuclear Materials (SNM), and illicit goods, like narcotics or smuggling materials. Fast 14 MeV neutrons are produced by a portable generator with the t(d, n)α fusion reaction, and tagged in both direction and time thanks to the alpha particle detection. This Associated Particle Technique (APT) allows focusing inspection on specific areas of interest in the containers, previously identified as containing suspicious items with X-ray radiographic scanners or radiation portal monitors. We describe the principle of APT for non-nuclear material identification, and for nuclear material detection, then we provide illustrations of the performances for 10 min inspections with significant quantities (kilograms) of explosives, illicit drugs, or SNM, in different cargo cover loads (e.g. metallic, organic, or ceramic matrices).

Since over 40 years, delivering state of art Power Supplies and Acquisition Systems for Nuclear, Cosmic and High Energy Physics detectors has been the constant mission of the CAEN R&D groups, working closely with the relevant scientists of major research labs worldwide. This paper will focus on some of these R&Ds concerning new power supplies specifically designed for the HL-LHC and new solutions for data acquisition in large experiments thanks to a modular approach or faster digitizers with open FPGA. The new power supply system, EASY6000, is introduced along its main new features like higher radiation tolerance to safely operate thru the whole LHC life span. Furthermore, the new system power density and efficiency in hostile environment are also analyzed, to better understand how much power can be directly delivered to the front-end of new detectors, moreover the communication link between the experiments and the control rooms is also reviewed. Among the data acquisition solutions a new family of digitizers is introduced featuring open FPGA and faster performance. Alongside, the Front End and Readout System (FERS) is presented: this new architecture provides a scalable and easy customizable data acquisition system, the concept is therefore introduced and the first prototypes are described, with their main characteristics.

Current state of the art solutions based on the Triple to Double Coincidence Ratio method are generally large size, heavy-weight and not transportable systems. This is due, on one side, to large detectors and scintillation chambers and, on the other, to bulky analog electronics for data acquisition. CAEN developed a new, full digital approach to TDCR technique based on a portable, stand-alone, high-speed multichannel digitizer, on-board Digital Pulse Processing and dedicated DAQ software that emulates the well-known MAC3 analog board. © 2013 Elsevier Ltd.

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.

International audience; Within the framework of the European H2020 C-BORD project, aiming at improving container inspection technologies, a compact and "Rapidly Relocatable Tagged Neutron Inspection System", called RRTNIS, is being developed taking into account past EURITRACK experience with a portal TNIS, and the latest technologies in terms of associated particle neutron generator and data acquisition electronics. A dedicated shield surrounding the neutron generator has been designed with MCNP6 to limit the size of the restricted area and the count rate on gamma detectors, which are located very close to the generator. This new design with "reflection" detectors only, i.e. in backscattering position, is indeed more efficient to detect suspect items, like explosives or illicit drugs, in bottom regions of the container, compared to EURITRACK detectors which were mainly located above the container. It also allows designing a relocatable system for different inspection sites like seaports, borders, or other checkpoints. Dose and count rate calculations are presented to determine the restricted area and facilitate the design of the data acquisition electronics, respectively.

Positron emission tomography (PET) is a means of imaging the β+-activity produced by the radiation field in ion beam therapy and therefore for treatment verification. Prompt γ-rays that are emitted during beam application challenge the detectors and electronics of PET systems, since those are designed for low and medium count rates. Typical PET detectors operated according to a modified Anger principle suffer from multiple events at high rates. Therefore, in-beam PET systems using such detectors rely on a synchronization of beam status and measurement to reject deteriorated data. In this work, a method for pile-up rejection is applied to conventional Anger logic block detectors. It allows for an in-beam data acquisition without further synchronization. Though cyclotrons produce a continuous wave beam, the radiation field shaping technique introduces breaks in the application. Time regimes mimicking synchrotrons as well as cyclotron based ones using double-scattering or pencil beam scanning field shaping at dose rates of 0.5, 1.0 and 2.0Gy/min were investigated. Two types of inhomogeneous phantoms were imaged. The first one simulates cavity structures, the other one mimics a static lung irradiation. It could be shown that, depending on the dose rate and the beam time structure, in-beam measurement including a few seconds decay time only, yield images which revealed all inhomogeneities in the phantoms. This technique can be the basis for the development of an in-beam PET system with traditional detectors and off-the-shelf electronics.

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.

In this contribution we introduce an innovative instrument for the education world to be used in physics and medical imaging courses. The instrument is able to generate analog signals with the same characteristics of the output of a real radiation detector under the influence of one or more radiation sources. Lot of experiments can be conducted when the educational detector emulator is connected to a digitizer or to a MCA.

We present a compact Multi Channel Analyzer that can be used in applications for energy measurements that range from X to Gamma ray spectroscopy for different types of detectors and preamps with continuous and pulsed reset. Main features of the instrument are the extreme compactness and the portability that make it suited both for laboratory and portable applications. It offers extreme versatility in power supply being able to use several power sources, i.e. electrical network, USB, Power over Ethernet. It can be directly interfaced with PC, Android-based devices and Apple devices via USB, Ethernet connectivity. The instrument has been fully engineered and characterized.

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.

We introduce an improved version of the Digital Detector Emulator able to generate programmable analog shapes with a rise time up to 1 ns. This is suitable for all the fast-scintillator emulation environments. Moreover, the output dynamic of 16 bits allows the device to be used in high resolution spectroscopy applications. The instrument is not a pulse generator of recorded shapes but a synthesizer of random pulses compliant to programmable statistics for height and starting time of events. The device also features programmable noise sources, disturbances and baseline variations. The implementation of an analog input channel allows the instruments to mix the emulated signals to real signals sampled by the input channel.

A system for the emulation of signals at the output of radiation detectors is presented. The process of generation is performed in real-time with no support of other external instrumentation. The produced signal are pulse whose shape, amplitude and occurrence time statistic distributions are a-priori defined by the end user.

In a liquid scintillator detector such as EJ-309, neutrons and gamma-rays give rise to different light pulse shapes due to the way they give up their energy but, in addition to this, there are fluctuations in the shape of the light pulse that varies with the point of interaction in the detector volume. The way in which light is dispersed and reflected throughout a detector volume introduces small fluctuations in the shape of the light pulse. This has an impact on the spread of pulses from neutrons and gamma rays and hence impacts the ability to perform discrimination of the two radiation types by pulse shape. This paper investigates, by experimentation, how the spread in the pulses produced by neutrons and gamma rays varies as the detector volume varies from 350 cubic centimeters to 6,570 cubic centimeters. The effect that this has on pulse shape discrimination performance is described. Also investigated are the effects of right-cylindrical geometries versus cuboid geometries. Pulse-shape discrimination of digitally captured neutron and gamma-ray event pulses was performed using the charge integration technique. A figure of merit at 100 keVee is seen to degrade by 25.2 ± 1.2% as the detector volume is increased from 350 to 6,570 cubic centimeters. At 1450 keVee this degradation increases to 30.9 ± 3.8%. In these experiments, cubic geometries appear to have similar pulse shape discrimination performance to right-cylindrical geometries. A 102 mm cube is calculated to have a figure of merit of 4.1 ± 0.7% better than a 102 × 102 mm cylinder at 100 keVee and on average about 4% better across the energy range 100 to 1450 keVee.

In this contribution, we present a configurable digital emulator of pulses which generates analog signals with fully programmable shape, energy and temporal distributions. Two independent channels, which can be related in terms of the instants of occurrence of the events, allow generation of pulses with programmable delay with resolution below 12 ps. The instrument also combines the advantage of being extremely compact and portable and is suitable for designing and debugging instrumentation in which the measurements also involve times of flight or temporal correlation, like in PET machines.

Silicon Photo-Multipliers (SiPM) are state of the art light detectors with unprecedented single photon sensitivity and photon number resolving capability, representing a breakthrough in several fundamental and applied Science domains. An educational experiment based on a SiPM set-up is proposed in this article, guiding the student towards a comprehensive knowledge of this sensor technology while experiencing the quantum nature of light and exploring the statistical properties of the light pulses emitted by a LED.

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 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.

Silicon Photomultipliers (SiPM) are a new class of photon sensors with single photon detection capability and high photon detection efficiency. They have been proved to be suitable for an increasing number of applications in science and industry. Nowadays, different companies are investing increasing efforts in SiPM detector performances and high quality mass production, such to make them a natural choice for an always wider field of applications. In this scenario, a flexible and easy-to-use system that allows the measurement of the main SiPM characteristics has become an important platform to exploit SiPMs in different applications. This system can also be used to setup a series of experiments aimed to train physics and engineering undergraduate and master students in detector measurements and statistics analysis.

International audience; The EURopean Illicit TRAfficing Countermeasures Kit project is part of the 6th European Union Framework Program, and aims at developing a neutron inspection system for detecting threat materials (explosives, drugs, etc.) in cargo containers. Neutron interaction in the container produces specific gamma-rays used to determine the chemical composition of the inspected material. An associated particle sealed tube neutron generator is developed to allow precise location of the interaction point by direction and time-of-flight measurements of the neutrons tagged by alpha-particles. The EURITRACK project consists in developing: a transportable deuterium-tritium neutron generator including a position sensitive alpha detector (8×8 matrix of YAP:Ce crystals coupled to a multi-anode photomultiplier), fast neutron and gamma-ray detectors, front-end electronics to perform coincidence and spectroscopic measurements, and an integrated software which manages neutron generator and detectors positioning, data acquisition and analysis. Hardware components have been developed and tested by the consortium partners. Current status of this work and provisional performances of the system assessed by Monte Carlo calculations are presented.

The EURopean Illicit TRAfficing Countermeasures Kit (EURITRACK) Front-End and Data Acquisition System is a compact set of VME boards interfaced with a standard PC. The system is part of a cargo container inspection portal based on the tagged neutrons technique. The front-end processes all detector signals and checks coincidences between any of the 64 pixels of the alpha particle detector and any gamma-ray signals in 22 NaI(Tl) scintillators. The system is capable of handling the data flow at neutron flux up to the portal limiting value of 10 8 neutrons/second. Some typical applications are presented.