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The electrical insulation of the Megavolt ITER Injector and Concept Advancement (MITICA) beam source (BS) at 1 MV in vacuum is a challenging issue, which could not be fully addressed so far on the basis of experimental results and of theoretical models available in literature. A specific high-voltage (HV) test campaign is being prepared to validate and optimize the voltage holding capability of the BS insulation under realistic conditions, using full-size mockup electrodes reproducing in detail the geometry of the BS and accelerator. The proposed test strategy will address both the single-gap and the multistage insulation, so as to obtain a verification of voltage holding at 1 MV before the installation of the real components. This approach is intended to reduce the risk related to the HV insulation at 1 MV and, if necessary, to allow the development of effective corrections. In this article, the test motivations and requirements are defined, and the electrode implementation and diagnostic setup are described. Finally, the test configurations and the experimental procedure are discussed.

The PRIMA project aims at the construction of two ITER-NBI facilities in Padova (Italy). The first one is called SPIDER which is negative H/D 100 keV RF source, while the second one (MITICA) will be a full scale 1 MeV deuterium beam injector as the one that will be used in ITER. In order to resolve the horizontal beam intensity profile in MITICA and one of the eight beamlets groups in SPIDER, the Close-contact Neutron Emission Surface Mapping (CNESM) system is being developed. The goal of this device is to reconstruct the D− beam evaluating the map of the neutron emission due to interaction of the deuterium beam with the deuterons implanted in the beam dump surface. For this reason, the CNESM diagnostic, which is based on nGEM detectors for fast neutrons, will be placed right behind the SPIDER and MITICA beam dump, i.e. in an UHV (Ultra High Vacuum) environment. Since the nGEM detectors need to operate at atmospheric pressure a vacuum sealed detector box has been designed to be installed inside the vacuum vessel and able to sustain atmospheric pressure inside. This paper describes the status of the CNESM diagnostic and underlines the different phases followed during the realization and installation of the diagnostic on the SPIDER beam dump as well as its imaging performances.

SPIDER is the prototype ion source for ITER Heating and Diagnostic Neutral Beams. To investigate the phase-space distribution of its beamlets, an Allison type emittance scanner was developed. This kind of diagnostic is widely used in ion sources for high-energy accelerators, but has never been employed in fusion-relevant ion sources. Its measurements will assess the optics properties of the beamlets of a large negative ion source, providing a local measurement of their phase-space structure, and they will be useful to validate numerical models. This paper presents the experimental setup of the diagnostic, describing the detector, its integration in SPIDER, the handling system and the control electronics. The effectiveness of the design of the detector Faraday cup to repel secondary electrons is experimentally proven. Finally, the emittance measurements obtained in a dedicated test facility are also reported and compared with ray tracing simulations.

Magnetic fields in negative ion driven Neutral Beam Injectors (NBIs) are essential to reduce the electron temperature and density in the extraction region, along with filtering out the otherwise unavoidably co-extracted electrons. In SPIDER, the full scale ion source and extractor of the ITER NBI, a horizontal magnetic field up to 8 mT inside the plasma source is produced by a current of up to 5 kA flowing through the plasma-facing electrode and additional bus-bars. First SPIDER experimental campaigns showed an influence on the plasma generation when the magnetic field is increased beyond a threshold. This effect has been ascribed to the particular topology of the field in the plasma volume inside the 8 inductively-coupled radio-frequency drivers that generate the plasma. The paper describes the experiments aimed at identifying the problem and the design process for a new layout of bus-bars capable of creating an optimized magnetic field topology within the RF driver, while keeping it almost unchanged in the other regions where the required performances were already achieved. Particular attention was given for a design leaving the possibility of easily modifying the new topology, so as to significantly expand the operating margin of the experimental activity.

In large multi-aperture, multi-grid negative-ion accelerator for fusion application, the background gas density in the electrostatic accelerator causes a loss of negative-ion current and the formation of dangerous stray particles. In addition, to sustain in dynamic equilibrium a sufficient gas pressure in the plasma ion-source, a very large pumping speed is typically necessary. This paper presents and compare simulations and measurements of gas flows and background pressure profiles, through the electrostatic accelerator of the SPIDER beam source, the full-size prototype source of the ITER neutral beam injectors. The gas pressure profiles through the ion accelerator were measured by multiple movable capacitive pressure gauges, mapping the uniformity of the profiles along nine beamlets at three different filling pressures. The gas flow simulations in molecular flow regime were performed with a large-scale view-factor model, and with a single-aperture periodic test particle Monte Carlo model. The models reproduced the measured pressure profiles but additionally, provided also the profiles of local gas density. The gas conductance and the profiles calculated with the full-scale gas flow model correctly reproduce the measured profiles, and the transversal non-uniformities over the 1.6 m × 0.6 m cross section. The calculated gas density profile is also verified by comparing the two different numerical approaches. The gas flow model validated at room temperature can be used to simulate the pressure profile during operation, in presence of gas heating and dissociation by the source plasma.

Low divergence negative ion beams are crucial for the development of ITER-like fusion reactors. SPIDER is the prototype beam source of the ITER heating neutral beam injector, and it recently started beam acceleration, up to a voltage of 30 kV. The main diagnostics used to measure beamlet divergence are a movable diagnostic calorimeter (STRIKE), which gives the thermal footprint of the beamlets; beam emission spectroscopy; and visible imaging. These systems do not allow a direct measurement of single beamlet phase-space distribution, which is useful for comparison with numerical simulations and to estimate accelerator performances. To this purpose, a movable Allison type emittance scanner for the SPIDER negative ion beam was developed and proposed for the installation on the STRIKE supporting structure. This paper describes the numerical analyses performed to dimension the mechanical and electrical components, such as the Faraday cup and the slits. An analytical approach based on the integration of an arbitrary phase-space distribution was adopted in order to simulate the device performances. The constraints due to the operation in a high heat load environment are discussed.

The ITER Neutral Beam Test Facility, in an advanced construction in Padova, includes the installation, tests, and optimization of the full prototype of the ITER Heating Neutral Beams injectors (HNBs), named MITICA. The MITICA Neutral Beam Injector will host its main items in a SS304L vacuum vessel composed of two modules, connected between them on site: the Beam Source Vessel (cubic of 5 m side and 67 tons weight) containing the ion Beam Source and the Beam Line Vessel (section 4.5 m x 4.5 m, length 11 m and 76 tons weight) containing the Beam Line Components and the Cryopumps. The project requirements were transferred in the manufacturing design and in the fabrication process of these large vessels produced through welding and machining. The following steps were in particular carried out before and during manufacturing: o FE analyses to assess the structural integrity and limited deformations under vacuum loading conditions (leading to ribs reinforcement) o materials selection suitable for the specific application o qualification of special processes (welding and NDE) to ensure control of welding distortions and leak tight joints o implementation of double barrier sealings for the most critical connections o control of deformations under vacuum loads comparing displacement measurements with results of FE analyses. The Factory Acceptance Tests of the individual vessels are presented, including their Helium Leak Tests. The two vessels have been assembled on-site inside the MITICA bio-shield. They have been connected through a double sealing barrier composed of elastomer and a leak tight welded flange connection, previously qualified at the factory. The main outcomes of on-site final assembly and Site Acceptance Tests are described. Both vessels have been manufactured, installed and tested by De Pretto Industrie; the design and the technical support were provided by Consorzio RFX, while the procurement was managed by F4E.

The ITER neutral beam test facility under construction in Padova will host two experimental devices: SPIDER, a 100 kV negative H/D RF beam source, and MITICA, a full scale, 1 MeV deuterium beam injector . SPIDER will start operations in 2016 while MITICA is expected to start during 2019. Both devices feature a beam dump used to stop the produced deuteron beam. Detection of fusion neutrons produced between beam-deuterons and dump-implanted deuterons will be used as a means to resolve the horizontal beam intensity profile. The neutron detection system will be placed right behind the beam dump, as close to the neutron emitting surface as possible thus providing the map of the neutron emission on the beam dump surface. The system uses nGEM neutron detectors . These are Gas Electron Multiplier detectors equipped with a cathode that also serves as neutron–proton converter foil. The cathode is designed to ensure that most of the detected neutrons at a point of the nGEM surface are emitted from the corresponding beamlet footprint (with dimensions of about 40×22 mm2) on the dump front surface. The size of the nGEM detector for SPIDER is 352 mm×200 mm. Several smaller size prototypes have been successfully made in the last years and the experience gained on these detectors has led to the production of the full size detector for SPIDER during 2014. This nGEM has a read-out board made of 256 pads (arranged in a 16×16 matrix) each with a dimension of 22 mm×13 mm. This paper describes the production of this detector and its tests (in terms of beam profile reconstruction capability, uniformity over the active area, gamma rejection capability and time stability) performed on the ROTAX beam-line at the ISIS spallation source (Didcot-UK).

SPIDER experiment is operating at the PRIMA site in Padova (I) since June 2018, with the aim of testing and optimizing the negative ion source prototype for ITER Heating Neutral Beam Injectors. In the first operational phase it was discovered that, as the in-vessel hydrogen pressure exceeds the design requirements, discharges occur on the back of the radio frequency source. A specific operational campaign allowed defining a threshold below which the discharge probability is strongly reduced. In order to extend the operational range of the source pressure above the nominal value, while a significant upgrade of the vacuum pumping system is designed and realized, it was decided to proceed with the SPIDER operations by applying a temporary solution. A mask was installed on the beam source plasma grid, closing most of its apertures, in order to reduce the gas conductance between the inside of the radio frequency source and the surrounding volume. At first only 80 over 1280 apertures are left open, with a specific layout properly arranged so as to guarantee the possibility to diagnose the beam characteristics and to evaluate its uniformity. In the paper the plasma grid masking system will be described in detail, together with the main design choices, the thermal and structural analyses and the tests that were carried out to get a validation of the whole system design. Finally, an overview of the behavior of plasma grid mask during SPIDER operations will be given.

The SPIDER Beam Source (BS), the first prototype of a full scale ion source for the ITER Heating Neutral Beam injector, was delivered to the Neutral Beam Test Facility (NBTF) site in Padova (Italy) after about five years procurement phase. A huge effort was devoted during the procurement for quality controls and testing at the supplier’s workshops. Several activities were also carried out on NBTF site for verification/adjustment of interfaces, solution of still open issues, as well as final tests before and after installation inside the vacuum vessel. The NBTF Team undertook the BS site acceptance tests including: pressure and leak tests of the hydraulic circuits; electrical tests; measurement of magnetic field profiles; functionality tests of diagnostics installed on the BS; checks of grids alignment by means of laser tracker. Accurate positioning of the BS inside the vacuum vessel was performed and various service lines were connected in a tight space. Several improvements were undertaken in order to guarantee reliability and reduce the risks during the commissioning and experimental campaign in 2018. After installation, the integrated commissioning phase was initiated, powering the RF and high voltage circuits, followed by the first operation in vacuum.

The ITER project requires additional heating by two neutral beam injectors, each accelerating up to 1 MV a 40 A beam of negative deuterium ions for one hour. Such requirements have never been reached, so it was decided to build in Padova a facility (PRIMA) that hosts two experimental devices: SPIDER, a 100 kV negative H/D RF beam source, and MITICA, a full-scale injector for the ITER NBI. SPIDER has begun operation in 2018, while MITICA is expected to start after 2020. In both devices the accelerated deuterium beam impinges on an actively cooled beam dump used to stop the deuterons. Detection of fusion neutrons produced between beam–deuterons and dump-embedded deuterons will be used as a means to resolve the horizontal beam intensity profile. A neutron detection system called Close-contact Neutron Emission Surface Mapping (CNESM) is installed right behind the SPIDER beam dump, with the aim to provide the neutron emission map of the beam dump surface. The core of this diagnostic system is an nGEM (neutron-Gas Electron Multiplier) detector which will be able to reconstruct the fast neutron beam profile with an efficiency of about 10−4. A crucial point in order to correctly reconstruct the profile of the deposited D − power is the directionality discrimination capability of the detector. This paper reports on the results of the characterization of the nGEM directionality capabilities, performed at the Frascati Neutron Generator (FNG) using 2.5 MeV neutrons, before installation of the detector inside the SPIDER vacuum vessel.

The full-size ITER ion source prototype SPIDER (Source for the Production of Ions of Deuterium Extracted from a Radio frequency plasma) has recently started beam operation, whose objective is to produce 100 keV, 60 A hydrogen negative ions for 1 h. The source is presently operated in the volume regime, and the beam power is consequently limited. In such a configuration, the high resolution calorimeter STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment), even though uncooled, may be used instead of the SPIDER beam dump without limiting the beam-on time. STRIKE is formed by unidirectional carbon fiber-carbon matrix (CFC) composite tiles that are exposed to the beam while their temperature is recorded by using two infra-red cameras. This setup, thanks to the moderate broadening of the temperature profile guaranteed by the anisotropy of CFC, allows for the determination of detailed features of the beam current distribution (spatial resolution is about 2 mm). Furthermore, positively biasing the CFC tiles permits a direct electrical measurement of the negative ion beam current. Besides the total beam current and beam uniformity, which can be retrieved both by calorimetry and electrical measurement, beamlet divergence and deflection can be determined by infra-red thermography. This contribution describes the characterization of the SPIDER negative ion beam as a function of the source and accelerator parameters by means of the diagnostic calorimeter STRIKE in the volume regime.

Courts have upheld insurers’ disclaimers on mold, lead, and asbestos claims under comprehensive general liability (CGL) policies, evidencing the importance of maintaining affirmative cover in the emerging environmental insurance marketplace. Removing a CGL mold, lead, or asbestos exclusion is helpful, but insurers may assert a coverage defense and not pay a claim for reasons that have included: failure to meet the burden of proof, failure to trigger coverage, an absolute pollution exclusion, a preexisting condition exclusion, a defective design exclusion, a faulty workmanship exclusion, a business risk exclusion, a known loss or loss in progress, a custody and control exclusion, an owned property exclusion, and late notice. Accordingly, affirmative coverage grants contained in environmental insurance policies are necessary to protect against such losses and maximize recoveries.

After installation of Mo liners in the source NIO1 (Negative Ion Optimization phase 1), hydrogen plasmas in a continuous regime operation (much longer than one hour) are routinely maintained, with more than 1 kW rf power and 0.5 Pa pressure, allowing a systematic investigation of pure H− volume effect, which requests a much lower acceleration voltage Vs ≅ 12 kV than future Cs operations at Vs ≅ 60 kV. A new extraction grid EG was installed (replacing some eroded insulators) and preliminary beam images are compared to old EG ones, discussing effects of different deflection field strength and need of intermediate values. Large improvements in beam diagnostics and the effect of installation of a cryogenic pump are also reported.

For ITER operations, additional heating systems are required. One of these systems is the neutral beam injector (NBI). The SPIDER experiment, a small-scale NBI, is going to be built with the aim to optimize the beam source. For this reason it is provided with several diagnostics, among which the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE). In this contribution, a characterization of the Carbon Fiber Composite (CFC) tiles, which are the main component of the diagnostic, is presented. Such analyses include tests with a power laser, exposure to particle beams and thermal stress tests. The results are discussed, which will drive the definition of the acceptance tests of the final supply of CFC tiles.

This paper describes the final design of the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE) for the SPIDER experiment (Source for Production of Ions of Deuterium Extracted from Radio frequency plasma) under construction at the Consorzio RFX premises. The STRIKE diagnostic will be used to characterise the SPIDER beam during short pulse operation (several seconds) to verify the degree of attainment of ITER requirements about the maximum allowed beam non-uniformity. After a preliminary design developed in the last few years, the complete STRIKE diagnostic system has been recently subjected to a final review and is now ready for construction. The main components of the system are: an array of 16 tiles made of Carbon Fibre Composite, which will be exposed to the high power density beam (of the order of 20 MW/m22) exiting from the SPIDER Beam Source; a supporting and positioning system, based on a set of structures made of stainless steel, with controlled moving systems, to be installed within the SPIDER vacuum vessel; a set of thermal, electric and thermo-graphic sensors to properly detect the operating conditions. The paper will focus in particular on the development of the engineering design of the supporting and positioning system, with a description of the relevant CAD and FEM analyses, and will give an overview of the complete system, with reference to the manufacture of CFC tile prototypes and to the choice of the complete set of sensors.

Additional heating will be provided to the thermonuclear fusion experiment ITER by injection of neutral beams from accelerated negative ions. In the SPIDER test facility, under construction at Consorzio REX in Padova (Italy), the production of negative ions will be studied and optimised. To this purpose the STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) diagnostic will be used to characterise the SPIDER beam during short operation (several seconds) and to verify if the beam meets the ITER requirement regarding the maximum allowed beam non-uniformity (below ±10%). The most important measurements performed by STRIKE are beam uniformity, beamlet divergence and stripping losses. The major components of STRIKE are 16 1D-CFC (Carbon matrix-Carbon Fibre reinforced Composite) tiles, observed at the rear side by a thermal camera. The requirements of the ID CFC material include a large thermal conductivity along the tile thickness (at least 10 times larger than in the other directions); low specific heat and density; uniform parameters over the tile surface; capability to withstand localised heat loads resulting in steep temperature gradients. So ID CFC is a very anisotropic and delicate material, not commercially available, and prototypes are being specifically realised. This contribution gives an overview of the tests performed on the CFC prototype tiles, aimed at verifying their thermal behaviour. The spatial uniformity of the parameters and the ratio between the thermal conductivities are assessed by means of a power laser at Consorzio RFX. Dedicated linear and non-linear simulations are carried out to interpret the experiments and to estimate the thermal conductivities; these simulations are described and a comparison of the experimental data with the simulation results is presented.

A neutron diagnostic based on Gas Electron Multiplier is proposed for the MITICA beam injector test facility. The detection system is called Close-contact Neutron Emission Surface Mapping (CNESM) and aims at providing the beam intensity profile on the horizontal direction by measuring the neutron emission from the beam dump surface by placing a detector right behind the dump. CNESM uses Gas Electron Multiplier detectors equipped with a cathode that also serves as neutron-proton converter foil, named nGEM. The cathode, made of a thin polythene film and an aluminium film, is designed for detection of neutrons emitted with and angle between 30 and 70 degrees with respect to the deuterium beam axis. Neutron scattering in the dump and neutron detection with the nGEM were simulated with the MCNP6.1.1 code.

This paper presents the results of numerical simulations and experimental tests carried out to assess the feasibility and suitability of graphite castellated tiles as beam-facing component in the diagnostic calorimeter of the negative ion source SPIDER (Source for Production of Ions of Deuterium Extracted from Radio frequency plasma). The results indicate that this concept could be a reliable, although less performing, alternative for the present design based on carbon fiber composite tiles, as it provides thermal measurements on the required spatial scale.

The TPE-RX Neutral Beam Injector, which provides a 25 keV positive ion beam energy with a maximum current of 50 A for a pulse duration of 30 ms, will be installed on RFX-mod thanks to the agreement with the AIST Institute of Tsukuba (Japan). The main scientific objective is the study of the behavior of the fast ions, which in the RFP helical equilibrium have exhibited very long confinement times. The integration of TPE-RX NBI on RFX-mod requires the development of several new components: a mechanical interface between the RFX-mod vacuum vessel and neutralizer; a Magnetic Residual Ion Dump; a new vacuum pumping system designed to maximize pumping and minimize beam stopping due to reionization. As regards the power supplies the compliance of the Japanese equipment to the Italian safety rules has been considered and layout studies have been carried out; the integration of the NBI control system in the RFX timing sequence has been studied as well.

Building “green” and seeking certification are becoming necessary considerations for any construction project or construction improvement. The benefits and risks associated with building green will be explored in this article, and insurance solutions are offered. Certified green structures should provide healthier environments to work and live. Productivity should increase and sickness and absenteeism should decrease. The popularity, importance, and number of green building projects will continue to increase. However, green building also involves increased litigation risks associated with design, construction, ownership, and operation. This article will explore those risks, and insurability of such claim exposures. Many of those risks are insurable; some are currently uninsurable.

Climate change, characterized by higher surface and water temperatures, will likely lead to more frequent and severe storms, floods, rising sea levels, wildfires, and loss of a variety of species. The monetary loss attributable to these events could be enormous, resulting in a variety of first-party insurance claims and third-party lawsuits. The availability of insurance coverage to pay these claims will depend on the nature of weather-related losses and the particular policies in force. Insurers have also begun to develop products that pay to rebuild to “greener” standards after fortuitous losses, encourage lower carbon emissions, and provide incentives for the implementation of sustainable business and personal practices.

A fundamental question reported in hundreds of court decisions and evaluated every day by claims adjusters is whether a constituent that caused injury and damage is a “pollutant.” If yes, the claim will most often not be covered under general liability, professional, property, umbrella, or other policies because of the applicability of a pollution exclusion. Based upon our review of 200 cases, we determined that in 140, or 70 percent of the time, the constituent was considered a “pollutant” and the insurance claim was denied. In order to have insurance for “irritants” or “pollutants,” an insured must obtain specific pollution coverage.

New York's new 107-page brownfields law encourages the redevelopment of contaminated properties in order to increase tax revenues, revitalize communities, create jobs, protect the environment, and preserve open space. The legislation contains significant financial incentives to volunteers and municipalities to investigate, remediate, and redevelop brownfields to promote the reuse of such properties. While the law provides certain liability protection for claims by the State, it retains the “polluter pays” philosophy and contains scary re-opener provisions. This article will provide a brief overview of New York's recently enacted environmental law and explain why the legislation encourages the procurement of environmental insurance to mitigate the risks inherent with brownfield redevelopment projects.

The SPIDER experiment (Source for the Production of Ions of Deuterium Extracted from an RF plasma) aims to qualify and optimize the full size prototype of the negative ion source foreseen for MITICA (full size ITER injector prototype) and the ITER Heating and Current Drive Injectors to be installed at ITER site. Both SPIDER and MITICA experiments are presently under construction at Consorzio RFX in Padova, with financial support from IO (ITER Organization), Fusion for Energy, italian research institutions and contributions from Japan and India Domestic Agencies. The vacuum vessel hosting the SPIDER beam source has been manufactured, tested and assembled on site during the last two years 2013-2014. The cylindrical vessel, about 6 m long and 4 m in diameter, is composed of two cylindrical modules and two torispherical lids at the ends. All the parts are made by AISI 304 stainless steel. The possibility of opening/closing the vessel for monitoring, maintenance or modifications of internal components is guaranteed by bolted junctions and suitable movable support structures running on rails fixed to the building floor. A large number of ports, about one hundred, are present on the vessel shell for diagnostic and service purposes. The main working steps for construction and specific technological issues encountered and solved for production are presented in the paper. Assembly sequences and tests on site (vacuum and functional tests) are furthermore described in detail, highlighting all the criteria and requirements for correct positioning and testing performances.

The ITER neutral beam test facility under construction in Padova will host two experimental devices: SPIDER, a 100 kV negative H/D RF source, and MITICA, a full scale, 1MeV deuterium beam injector. A detection system called Close - contact Neutron Emission Surface Mapping (CNESM) is under development with the aim to resolve the horizontal beam intensity profile in MITICA and one of the eight beamlet groups in S PIDER, with a spatial resolution of 3 and 5 cm2 respectively. This is achieved by the evaluation of the map of the neutron emission due to interaction of the deuterium beam with the deuterons implanted in the beam dump surface. CNESM uses nGEM detectors, i .e. GEM detectors equipped with a cathode that also serves as neutron - proton converter foil. The diagnostic will be placed right behind the SPIDER and MITICA beam dump, i.e. in an UHV environment, but the nGEM detectors need to operate at atmospheric press ure, so to contain the detector a vacuum sealed box has been designed to be installed inside the vacuum vessel and at atmospheric pressure inside. The box design was driven by the need to minimize the neutron attenuation and the distance between the beam d ump surface and the detector active area. This paper presents the status of the CNSESM diagnostics and describes the design of the detectors and of the sealed box (in particular the analysis carried out to define its parameters, the necessary pumping and l eak test procedures to ensure the compatibility of the box with the UHV environment and the proposed installation/removal procedure ). Also the general layout of the diagnostic as part of the SPIDER experiment will be discussed. Finally the preliminary des ign of MITICA CNESM diagnostic will be introduced. This work was set up in collaboration and financial support of Fusion for Energy.

In the framework of the accompanying activity for the development of the two neutral beam injectors for the ITER fusion experiment, an instrumented beam calorimeter is being designed at Consorzio RFX, to be used in the SPIDER test facility (particle energy 100keV; beam current 50A), with the aim of testing beam characteristics and to verify the source proper operation. The main components of the instrumented calorimeter are one-directional carbon-fibre-carbon composite tiles. Some prototype tiles have been used as a small-scale version of the entire calorimeter in the test stand of the neutral beam injectors of the LHD experiment, with the aim of characterising the beam features in various operating conditions. The extraction system of the NIFS test stand source was modified, by applying a mask to the first gridded electrode, in order to isolate only a subset of the beamlets, arranged in two 3x5 matrices, resembling the beamlet groups of the ITER beam sources. The present contribution gives a description of the design of the diagnostic system, including the numerical simulations of the expected thermal pattern. Moreover the dedicated thermocouple measurement system is presented. The beamlet monitor was successfully used for a full experimental campaign, during which the main parameters of the source, mainly the arc power and the grid voltages, were varied. This contribution describes the methods of fitting and data analysis applied to the infrared images of the camera to recover the beamlet optics characteristics, in order to quantify the response of the system to different operational conditions. Some results concerning the beamlet features are presented as a function of the source parameters.

The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features of the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.

The ITER neutral beam injection system is being designed to provide 33 MW of heating from two injectors, with an upgrade to 50 MW possible with a third injector; such heating power will be provided by accelerating negative ions to high energies, 1 MeV, and neutralizing them. These neutrals are then injected into the tokamak where they impart their energy by collisions. To study and optimize negative ion production, the SPIDER prototype is under construction in Padova, Italy, whose beam has an energy of 100 keV and a current of 48 A. The instrumented calorimeter Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE) has been designed with the main purpose of characterizing the SPIDER negative ion beam in terms of beam uniformity and beam divergence during short operations (several seconds). STRIKE is made of 16 1-D carbon fiber composite (CFC) tiles, intercepting the whole beam and observed from the rear side by infrared (IR) cameras. With two identical samples of the CFC material and the IR camera under assessment, a reduced version of the entire calorimeter has been built, with the purpose of characterizing its diagnostic properties. This mini-STRIKE was used in the BATMAN experiment at Max Planck Institut fu?r Plasmaphysik (Garching, Germany). As the beamlet divergence in BATMAN is large, the beamlets overlap each other in the measurement position; therefore, the mini-STRIKE for BATMAN includes a copper mask, facing the beam and featuring eight apertures. Thus, eight different portions of the beam can be simultaneously sampled, with minimal overlapping of the power coming from adjacent apertures. The copper mask was actively cooled, and calorimetry was carried out. The temperature in the center of the mask and some positions along the CFC tiles was also measured. In this paper, the design of the system is presented. The calorimetry system is presented in detail as well as the procedure adopted for calorimetrical data analysis. The results of - alorimetry are presented together with preliminary correlations with the BATMAN beam features.

Fusion reactors will need high flux neutron detectors to diagnose the deuterium-deuterium and deuterium-tritium. A candidate detection technique is the Gas Electron Multiplier (GEM). New GEM based detectors are being developed for application to a neutral deuterium beam test facility. The proposed detection system is called Close-contact Neutron Emission Surface Mapping (CNESM). The diagnostic aims at providing the map of the neutron emission due to interaction of the deuterium beam with the deuterons implanted in the beam dump surface. This is done by placing a detector in close contact, right behind the dump. CNESM uses nGEM detectors, i.e. GEM detectors equipped with a cathode that also serves as neutron-proton converter foil. After the realization and test of several small area prototypes, a full size prototype has been realized and tested with laboratory sources. Test on neutron beams are foreseen for the next months. © 2014 American Institute of Physics.

Attempts by some courts to maximize insurance coverage in cases before them have resulted in some unfortunate and diverse rulings as to which policy periods should be implicated and how to assess the amount of costs attributable to policy periods when an insured is responsible for remediation costs to clean up contamination. This article argues for a manifestation trigger of coverage because it follows the fundamental principles of insurance law, provides simplicity and certainty as to date of loss, and avoids allocation battles. An injury‐in‐fact trigger is an alternative approach which is consistent with most insurance contracts as long as the insured demonstrates that some actual damage occurred during the policy period. This article advocates the pro rata time‐on‐the‐risk allocation approach adopted in Northern States Power when multiple periods of time are triggered, and disagrees with the joint and several liability allocation approach adopted in Keene and recently in CSXT. Some courts’ allocation a...

SPIDER, a prototype negative ion source with low voltage extraction for the ITER neutral beam injector will be equipped with a set of diagnostics to qualify and optimize the neutral beam for ITER. In particular, the visible tomography diagnostic will estimate the uniformity of the beam using a set of linear charge-coupled device cameras, while emission spectroscopy will measure the spatial variation of plasma parameters in the RF plasma source and evaluate the divergence of the extracted beam, analyzing the spectrum collected over multiple lines of sight (LOS). This paper presents the optical layout of the LOS and detection heads of tomography and spectroscopy and the required accuracy in their alignment, proposing also alignment criteria.

The ITER heating neutral beam injector, based on 1 MV D − ions, will be tested and optimized in the SPIDER source and MITICA full injector prototypes, using a set of diagnostics not available on ITER. Beam intensity uniformity is required to stay within ±10%, thus beam profile is measured with a complementary set of diagnostics. Among them, visible tomography measures the line of sight (LOS) integrated H α or D α radiation generated by the collisions between fast particles and neutral background molecules, and emitted on a plane perpendicular to the beam. A sufficient number of well arranged LOSs allows a tomographic reconstruction of the 2D beam emission profile, which is proportional to the beam density. On SPIDER the system is equipped with about 3000 LOSs, grouped in 15 fans, and the tomographic algorithm is based on the pixel method. The design of the diagnostic is presented, with description of layout and main components and test of the prototype linear CCD camera.

Fast neutron detectors with a sub-millimetric space resolution are required in order to qualify neutron beams in applications related to magnetically-controlled nuclear fusion plasmas and to spallation sources. A nGEM detector has been developed for the CNESM diagnostic system of the SPIDER NBI prototype for ITER and as beam monitor for fast neutrons lines at spallation sources. The nGEM is a triple GEM gaseous detector equipped with polypropylene and polyethylene layers used to convert fast neutrons into recoil protons through the elastic scattering process. This paper describes the results obtained by testing a nGEM detector at the ISIS spallation source on the VESUVIO beam line. Beam profiles (?x=14.35 mm, ?y=15. 75 mm), nGEM counting efficiency (around 10-4 for 3 MeV

The ITER project requires additional heating via injection of neutral beams, provided by two injectors accelerating negative ions. To study and optimise negative ion production, the SPIDER prototype is under construction in Padova, whose beam has an energy of 100keV and a current of 50A. The instrumented calorimeter STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) has been developed with the main purpose of characterising the SPIDER negative ion beam in terms of beam uniformity and beam divergence during short pulse operations (several seconds). STRIKE is made of 16 1D Carbon Fibre Composite (CFC) tiles, intercepting the whole beam and observed on the rear side by infrared (IR) cameras. Prototypes of the CFC material were procured and this contribution presents experimental tests and numerical simulations devoted to the characterisation of the CFC properties and to the assessment of the performance of the diagnostic. Tests are described, performed using a CO 2 laser to investigate the spatial resolution of the diagnostic on the scale lengths and with the experimental layout expected in SPIDER. Data recorded by an IR camera during the experiments are compared with simulations aiming to reproducing the experimental data with the purpose of validating the thermal parameters of CFC.