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The Joint European Torus (JET) has recently conducted its second deuterium-tritium (DT) experimental campaign DTE2, providing unique opportunity for studying both physics and engineering aspects of nuclear fusion plasmas. This also allowed the exploitation of new diagnostics and technologies that were not available during the first JET DT campaign held in 1997. Among these new instruments, the enhancement projects of the JET nuclear diagnostics lead to the development and installation of synthetic single crystal diamond detectors along different collimated line of sights. This paper describes the single crystal diamond-based diagnostic suite of the JET tokamak and the enhanced 14 MeV neutron diagnostic capabilities in terms of neutron yield and high resolution neutron spectroscopy. The diamond characterization measurements and the calibration procedure at JET are shown, together with performance of the diamond based neutron spectrometer as 14 MeV neutron yield monitor which allows the separation of 2.5 MeV and 14 MeV neutrons in trace tritium plasmas. The first high-resolution 14 MeV neutron spectroscopy measurements in neutral beam injection-heated DT plasmas are presented, allowing thermal and non-thermal neutron component separation. Prospects for the diagnose of DT burning plasmas such as ITER and SPARC will be presented.

TOFOR is a time-of-flight (TOF) neutron spectrometer located at the Joint European Torus (JET) with a vertical sightline of the JET plasma. It consists of 5 start (denoted S1) and 32 stop (denoted S2) plastic scintillation detectors which can be used in coincidence to generate a TOF spectrum. Spectroscopic analysis of the neutron TOF spectra produced by the JET plasma is regularly performed to determine, e.g., the fuel ion ratio and the presence of fast ion species in the fusion plasma. TOFOR has been upgraded with a new digital data acquisition (DAQ) system, denoted TOFu, which consists of 10 waveform digitizers with a total of 40 channels, 37 of which are connected to the photomultiplier output of the different S1 and S2 detectors. This paper presents a technical overview of the TOFu system and describes the offline analysis capabilities of TOFu which were not available with the previous DAQ system. Two experimental JET discharges are studied and used to show that the signal-to-background ratio is improved by almost 200% for the 2.5 MeV neutron signal and almost 400% for the 14 MeV neutron signal using the new offline analysis capabilities.

The IFMIF-DONES Facility is a unique first-class scientific infrastructure whose construction is foreseen in Granada, Spain, in the coming years. Strong integration efforts are being made at the current project phase aiming at harmonizing the ongoing design of the different and complex Systems of the facility. The consolidation of the Diagnostics and Instrumentation, transversal across many of them, is a key element of this purpose. A top-down strategy is proposed for a systematic Diagnostics Review and Requirement definition, putting emphasis in the one-of-a-kind instruments necessary by the operational particularities of some of the Systems, as well as to the harsh environment that they shall survive. In addition, other transversal aspects such as the ones related to Safety and Machine Protection and their respective requirements shall be also considered. The goal is therefore to advance further and solidly in the respective designs, identify problems in advance, and steer the Diagnostics development and validation campaigns that will be required. The present work provides an overview of this integration strategy as well as a description of some of the most challenging Diagnostics and Instruments within the facility, including several proposed techniques currently under study.

Spherical tokamaks are key to the successful design of operating scenarios of future fusion reactors in the areas of divertor physics, neutral beam current drive and fast ion physics. MAST Upgrade, which has successfully concluded its first experimental campaign, was specifically designed to address the role of the radial gradient of the fast ion distribution in driving the excitation of magneto-hydrodynamic (MHD) instabilities, such as toroidal Alfven eigenmodes, fish-bones and long-lived mode, thanks to its two tangential neutral beam injection systems, one on the equatorial plane and one that is vertically shifted 65 cm above the equatorial plane. To study the fast ion dynamics in the presence of such instabilities, as well as of sawteeth and neo-classical tearing modes, several fast ion diagnostics were upgraded and new ones added. Among them, the MAST prototype neutron camera (NC) has been upgraded to six, equatorial sight-lines. The first observations of the confined fast ion behavior with the upgraded NC in a wide range of plasma scenarios characterized by on-axis and/or off-axis heating and different MHD instabilities are presented here. The observations presented in this study confirm previous results on MAST but with a higher level of detail and highlight new physics observations unique to the MAST Upgrade. The results presented here confirm the improved performance of the NC Upgrade, which thus becomes one of the key elements, in combination with the rich set of fast ion diagnostics available on the MAST Upgrade, for a more constrained modeling of the fast ion dynamics in fusion reactor relevant scenarios.

The JET neutron camera is a well-established detector system at JET, which has 19 sightlines each equipped with a liquid scintillator. The system measures a 2D profile of the neutron emission from the plasma. A first principle physics method is used to estimate the DD neutron yield that is based on JET neutron camera measurements and is independent of other neutron measurements. This paper details the data reduction techniques, models of the neutron camera, simulations of neutron transport, and detector responses used to this end. The estimate uses a simple parameterized model of the neutron emission profile. The method makes use of the JET neutron camera’s upgraded data acquisition system. It also accounts for neutron scattering near the detectors and transmission through the collimator. These components together contribute to 9% of the detected neutron rate above a 0.5 MeVee energy threshold. Despite the simplicity of the neutron emission profile model, the DD neutron yield estimate falls on average within 10% agreement with a corresponding estimate from the JET fission chambers. The method can be improved by considering more advanced neutron emission profiles. It can also be expanded to estimate the DT neutron yield with the same methodology.

Frågan om jakt på varg bidrar till att legitimera eller öka acceptansen för varg ochvargförvaltning har stötts och blötts inom forskning, politik och förvaltning under många år. Inom såväl politiken som forskningsvärlden råder det delade meningar om huruvida jakten verkligen kan bidra till att öka acceptansen. En anledning till oenigheten är att det saknas evidensbaserade studier som genomförts med tillräckligt hög validitet och tillförlitlighet. Genom sådana studier kan man bekräfta eller förkasta att jakt som förvaltningsåtgärd bidrar till att påverka människors attityder, och i förlängningen beteenden, som till exempel kan bidra till att förebygga illegal jakt. I denna studie valdes genomförandet av vargjakten i Sverige år 2021/2022 ut som en unik möjlighet att med rigorösa metoder fånga upp jaktens eventuella effekter på attityder till varg, vargpolitik och vargförvaltning, samt förtroendet för förvaltande myndigheter. Studien utformades med syfte att undersöka effekterna av licensjakt på varg bland allmänheten, samt bland direkt och indirekt berörda aktörer i vargfrågan. Studien kombinerar kvantitativa och kvalitativa metoder och består av tre moduler: 1) en kartläggning av allmänhetens attityder före (n = 5 470 personer) och efter licensjakten (n = 7 432 personer) i län med licensjakt och utan licensjakt, 2) en intervjustudie med aktörer som är involverade i eller är direkt påverkade av beslutsprocessen rörande licensjakten, och 3) en analys av sociala mediers bevakning av licensjakten för att förstå den bredare samhällsdebatten. En slutsats av den här och tidigare studier är att det finns ett omfattande och stabilt stöd bland allmänheten för jakt på varg om syftet är att reglera vargpopulationen (Dressel m fl, 2021). Licensjakten på varg under 2021, som en enskild förvaltningsåtgärd, har däremot inte visat någon stark effekt på allmänhetens attityder till varg, dess politik och förvaltning eller tillit till förvaltande myndigheter. Den kvantitativa undersökni

Climate change represents a growing ecological challenge. The (sub) arctic and boreal regions of the world experience the most rapid warming, presenting an excellent model system for studying how climate change affects mammals. Moose (Alces alces) are a particularly relevant model species with their circumpolar range. Population declines across the southern edge of this range are linked to rising temperatures. Using a long-term dataset (1988–1997, 2017–2019), we examine the relative strength of direct (thermoregulatory costs) and indirect (food quality) pathways linking temperature, precipitation, and the quality of two important food items (birch and fireweed) to variation in moose calf mass in northern Sweden. The direct effects of temperature consistently showed stronger relationships to moose calf mass than did the indirect effects. The proportion of growing season days where the temperature exceeded a 20 °C threshold showed stronger direct negative relationships to moose calf mass than did mean temperature values. Finally, while annual forb (fireweed) quality was more strongly influenced by temperature and precipitation than were perennial (birch) leaves, this did not translate into a stronger relationship to moose calf weight. The only indirect path with supporting evidence suggested that mean growing season temperatures were positively associated with neutral detergent fiber, which was, in turn, negatively associated with calf mass. While indirect impacts of climate change deserve further investigation, it is important to recognize the large direct impacts of temperature on cold-adapted species.

Collaborative governance regimes may be vulnerable because of dependency on stakeholders’ voluntary engagement and efforts. This study focuses on the Swedish moose management system, a multi-level collaborative governance regime inspired by the ecosystem approach. Self-determination theory is used to explore perceived prerequisites of basic needs for intrinsic motivation across sub-groups of stakeholder representatives who are engaged across different social-ecological contexts. Questionnaire data collected among representatives at two governance levels, moose management groups (n = 624) and moose management units (n = 979), were subjected to two-step cluster analysis. The analyses revealed two sub-groups of representatives, characterized by differences in species composition and land ownership structure: managers of multi-ungulate areas and managers of large-carnivore areas. In several respects, these groups significantly differed in how they perceived the prerequisites. This included prerequisites of perceived competence with regard to their need for knowledge of topics and usefulness of monitoring methods, perceived autonomy operationalized as possibilities to perform their tasks with sufficient time, resources, and support from their organizations, and perceived relatedness to different groups of actors. Further efforts should be made to understand the conditions required for representatives to energize and direct their behavior. The institutional system must better fit the needs of stakeholder representatives across various local contexts, otherwise the space for local voluntary engagement might be hampered.

The purpose of this work is to process lightning data from the Swedish Meteorological and Hydrological Institutes (SMHI) lightning location system to analyze which currents occur during lightning strikes in Sweden. The result can then be compared with the values currently used in dimensioning lightning protection for the transmission network, to evaluate whether the design of the protection is relevant with regard to the currents registered by the lightning location system. The results based on the years 2015-2020 show that the current distribution fits a lognormal and generalized extreme value distribution, the latter yielding a slightly better representation. The national analysis shows a significantly lower median peak current in Sweden compared to the reference median peak current recommended by CIGRE.

Här undersöker vi hur älgpopulationens storlek förändrats sedan den nya älgförvaltningen infördes jaktåret 2012/13, samt hur populationsmålen, avskjutningsmålen och avskjutningen förhållit sig till varandra. Vidare undersöker vi hur antalet tallar per hektar och andelen tallar som skadats av vilt förändrats sedan den enhetliga älgbetesinventeringen infördes jaktåret 2014/15, samt sambanden mellan älgtäthet, talltäthet och andel skadade tallar. Vi använde data från Skogsstyrelsens Älgbetesinventering ÄBIN och en ny skattningsmetod för älgtäthet som bygger på avskjutningsdata och de älgobservationer som jägarna samlar in under älgjakten. Den svenska älgpopulationen minskade från c:a 287 000 till c:a 260 000 älgar efter jakt under 2014/15–2020/21. Populationsmålen på älgförvaltningsområdesnivå nåddes med 3–6 års eftersläpning. Sambanden mellan nyttjandegraden av avskjutningsmålen och måluppfyllnad av täthetsmålen var svaga. Jämförelser mellan populationstätheter skattade med den nya metoden och bedömda populationstätheter från älgförvaltningsplanerna visar att älgförvaltningen tenderat att överskatta populationen vid låga tätheter och underskatta populationen vid höga tätheter. Den nya beräkningsmodellen medger enhetliga underlag och en större precision och noggrannhet i planarbetet inom älgförvaltningen. Talltätheten i inventerade bestånd ökade i södra Sverige under perioden och där minskade även skadorna. Jämförelser av den relativa betydelsen av älgtäthet och talltäthet för andelen skadade tallar visade att talltätheten genomgående hade större betydelse för skadebilden än älgtätheten på lokal, regional och nationell skala. Resultaten visar på en avsevärt större slumpmässig mellanårsvariation i antal tallar per hektar och i andelen årsskadade tallar, jämfört med variationen i älgtäthet. Den stora mellanårsvariationen i andelen skadade tallar gör att det kan ifrågasättas om det är lämpligt att fastställa förvaltningsmål för älgpopulationens storlek enbart baserat på

A new deuterium-tritium experimental, DTE2, campaign has been conducted at the Joint European Torus (JET) between August 2021 and late December 2021. Motivated by significant enhancements in the past decade at JET, such as the ITER-like wall and enhanced auxiliary heating power, the campaign achieved a new fusion energy world record and performed a broad range of fundamental experiments to inform ITER physics scenarios and operations. New capabilities in the area of fusion product measurements by nuclear diagnostics were available as a result of a decade long enhancement program. These have been tested for the first time in DTE2 and a concise overview is provided here. Confined alpha particle measurements by gamma-ray spectroscopy were successfully demonstrated, albeit with limitations at neutron rates higher than some 10(17) n/s. High resolution neutron spectroscopy measurements with the magnetic proton recoil instrument were complemented by novel data from a set of synthetic diamond detectors, which enabled studies of the supra-thermal contributions to the neutron emission. In the area of escaping fast ion diagnostics, a lost fast ion detector and a set of Faraday cups made it possible to determine information on the velocity space and poloidal distribution of the lost alpha particles for the first time. This extensive set of data provides unique information for fundamental physics studies and validation of the numerical models, which are key to inform the physics and scenarios of ITER. Published under an exclusive license by AIP Publishing.

This paper investigates the determination of the fuel ion ratio nT/ntot in fusion experiments using two different approaches. The methods are applied to plasma discharges from the deuterium-tritium campaign at the Joint European Torus (JET) in 1997. Multiple discharges have been analysed using data acquired with the Tandem (KM2) neutron spectrometer, using a new neutron spectrometer response function and improved line-of-sight information.The two different approaches were generally similar with the exception of the beam slowing down modelling, handled by two different particle transport codes, namely, TRANSP and PENCIL.The results show that nT/ntot can be determined using Tandem neutron spectrometer data; nT/ntot using both of the approaches are consistent and within the uncertainty for a range of studied discharges.The obtained results support previous studies on nT/ntot determination using neutron spectroscopy. In addition, we have shown that PENCIL can be used instead of TRANSP for a range of discharges which could simplify and speed up the estimation of nT/ntot. The possible limitations of the approach using PENCIL could be investigated using different neutron spectrometer data from the 2021 JET deuterium-tritium campaign.A similar spectrometer like Tandem is planned to be operational at ITER and the results of this paper form the first experimental verification of the capability for nT/ntot measurements with such spectrometers. Further research on this could lead to better understanding of these instruments and their limitations before the start of experiments at ITER., JET (Joint European Torus) medarbetare står som gruppförfattare i artikeln.Här har de affilierade vid Uppsala Universitet tagits med.

The future DEMO tokamak will be equipped with a suite of diagnostics which will operate as sensors to monitor and control the position and operation parameters of DT plasmas. Among the suite of sensors, an integrated neutron and gamma-ray diagnostic system is also studied to verify its capability and performance in detecting possible DEMO plasma position variations and contribute to the feedback system in maintaining DEMO DT plasma in stable conditions. This work describes the progress of the conceptual study of the gamma-ray diagnostic for DEMO reactor performed during the first Work-Package contract 2015-2020. The reaction of interest for this Gamma-Ray Spectrometer Instrument (GRSI) consists of D(T, gamma)He-5 with the emission of 16.63 MeV gamma rays. Due to DEMO tokamak design constraints, the gamma and neutron diagnostics are integrated, both featuring multi-line of sight (camera type), viewing DEMO plasma radially with vertical (12) and horizontal (13) viewing lines to diagnose the. and neutron emission from the DT plasma poloidal section. The GRSI design is based on the investigation of the reaction cross sections, on the calculations performed with GENESIS and MCNP simulation codes and on the physics and geometry constrains of the integrated instrument. GRSI features long collimators which diameters are constrained by the neutron flux at the neutron detectors of the Radial Neutron Camera (RNC) system placed in front, which are key to control DEMO DT plasma position. For these reasons, only few GRSI parameters can be independently selected to optimize its performance. Among these, the choice of the collimator diameters at the back side of the neutron detector box up to the GRSI detector, the use of LiH neutron attenuators in front of the GRSI detectors, the GRSI detector material and shielding. The GRSI detector is based on commercial LaBr3(Ce) inorganic scintillating crystal coupled with a photomultiplier tube or a silicon photomultiplier. They are designed