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The EUROfusion activities on the technological exploitation of deuterium–tritium (DT) operation at JET (started within the work package JET3 and continued under PrIO) were established to maximize the scientific and technological return of DTE2 campaign occurred in the second part of 2021. In particular, the aim of the NEXP sub-project was to take advantage of the expected significant neutron production during DTE2 to validate the numerical tools used for neutron streaming and shutdown dose rate (SDR) calculation for ITER through the comparison between numerical predictions and measurements. In the frame of SDR activity, a dosimetry system to measure the dose rate and based on some ionization chambers (ICs) was installed in the torus hall and upgraded both hardware and software since 2015 by exploiting the previous DD and TT campaigns. Two spherical 1-L air-vented ICs had been installed in some ex-vessel positions close to the horizontal ports of the tokamak in octants 1 and 2 and a third IC, suitable for higher dose rates, was then added in octant 1. As for SDR calculation, numerical tools employed rely on MCNP code for radiation transport and in this regard the MCNP model has been updated to include the last detector installed in octant 1. The present work is dedicated to the analysis of dose rate measurements carried out during DTE2 in the inter-pulse periods and at the shutdown. Influence quantities and error sources are analyzed to calculate the dose rate from raw signal and experimental uncertainty. Some experimental points are chosen and employed for a preliminary comparison with numerical predictions obtained from three-dimensional simulations with Advanced D1S tool. The results are presented and discussed with the major objective to contribute to the optimization of the planned SDR code validation. [ABSTRACT FROM AUTHOR]

To test the applicability of self-powered detectors (SPDs) for radiation monitoring in fusion reactor blankets, several irradiation tests have been undertaken with the ad hoc designed Cr-SPD, which presents the novelty of using chromium as the emitter material. This detector was exposed to an intense 60Co gamma-ray source, and to the 14 MeV neutrons produced by the D–T fusion reaction. Detailed analyses of the measured signals have been done here using a Monte Carlo modeling technique. We describe the simulations of the fusion neutron and gamma tests of the Cr-SPD, and compare their results with the experimental ones. Keeping in view the difficulty in computational reproduction of the sophisticated nuclear-electrical phenomena behind low-level SPD signals, our model is found to perform well, giving correct electrical polarities and orders of magnitude of the signals, as well as valuable insights into their different components. Our experience has highlighted the deficits and the needed improvements for the traditional SPD simulation techniques for prompt signal analyses. [ABSTRACT FROM AUTHOR]

The article presents the discussion on programs updating the current compensation structures as traditional compensation models. Topics include workgroup developed specific service categories for describing the work physicians performing regularly as part of the normal activities on a daily basis; and implementing a value-based model by revising the health care providers (HCP) compensation structure.

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Many studies showed that there are associations between particulate matter (PM) emissions and negative health effects. Sources for particulate matter PM emissions are, in addition to industry and traffic, residential wood combustion. Such PM emissions consist typically of non-combustible impurities contained naturally within the wood fuels (e.g., ash). Additionally, heavy metals from the wood fuel and/or polycyclic aromatic hydrocarbons (PAHs) formed during incomplete combustions may condense on the surface of these particulate matter and may increase the toxicity of these particles. To reduce negative health effects, wood combustion appliances are forced to emit less PM emissions. This may lead to an increased use of electrostatic precipitators to meet the valid threshold values. Against this background, the overall goal of this paper is it to compare biological effects of PM emissions released under full- and partial-load conditions of a wood pellet boiler with and without a flue gas treatment with an electrostatic precipitator in bacterial assays. The results show that PM emissions emitted under full-load conditions show a lower cytotoxic potential than those collected under partial load. No difference for the genotoxicity between full-load and partial-load conditions could be identified. However, significantly lower genotoxicity during full-load operation and precipitation but higher genotoxicity during partial load and precipitation have been found. Conclusively, the results indicate that the PM emissions emitted under full-load conditions show overall less cytotoxicity and genotoxicity than the emissions from partial-load operation. The PAH concentration doubles between full load and partial load with separator and quadruples between full load and partial load without precipitator. [ABSTRACT FROM AUTHOR]

Neutron and gamma flux measurements in designated positions in the test blanket modules (TBMs) of ITER will be important tasks during its campaigns. Investigations on self-powered detectors (SPDs), a class of reactor flux monitors are undertaken in the framework of an ongoing project on development of nuclear instrumentation for European ITER TBMs. This paper reports the findings of experiments performed with an SPD in flat sandwich-like geometry. A detector with vanadium emitter is chosen for preliminary studies. Its irradiation in a thermal neutron field gives a proof of the principle of flat SPDs. It is further irradiated in the mixed neutron–gamma field of a 14-MeV neutron generator and a bremsstrahlung photon field. The test SPD signals are proportional to the incident fluxes, deeming it suitable for flux monitoring. Whereas both neutrons and gammas can be detected with appropriate optimization of geometries, materials, and sizes of the components, the present design is more sensitive to gammas than fast neutrons. Based on the measured sensitivities of the SPD, its response under TBM conditions is predicted. [ABSTRACT FROM AUTHOR]

Radiation detectors based on wide-bandgap semi- conductors have received considerable attention in many applications such as the experiments in material testing reactors, high energy particle physics experiments, or fusion facilities for plasma diagnostics. In this paper, we compared a 4H-silicon-carbide (SiC)-based detector with a single crystal chemical vapor deposited (sCVD) diamond-based detector for 14-MeV neutron detection. For this purpose, the deuterium–tritium neutron generator of Technical University of Dresden with 14-MeV neutron output up to 1011 n/sin $4\pi $ has been used. In this paper, we interpret the results of our first measurements with both 4H-SiC and sCVD diamond detectors at low neutron flux of $9.4 \times 10^{6}\text {n}/(\mathrm {cm}^{2}\cdot \text {s})$ and at room temperature. [ABSTRACT FROM AUTHOR]

Examination of Ga2O3 as solid-state nuclear detector was carried out. Ga2O3 is a wide bandgap material with beneficial physical properties that enable its application in harsh environmental conditions, such as elevated temperature or strong electromagnetic field; therefore, Ga2O3 could become a competitor of diamond and 4H silicon-carbide nuclear detectors. Furthermore, because of its high oxygen content the new detector material can play an important role in the field of reactor research due to the 16O(n, \alpha )^13\textC reaction. Monocrystalline $\beta $ -Ga2O3 samples were investigated under 14 MeV fast neutron irradiation. On unintentionally doped semiconducting and Mg-doped insulating crystals metallic films were deposited in order to form the contact electrodes for biasing and to collect the electron-hole pairs generated by secondary particles after nuclear interactions between neutrons and the nuclei of the Ga2O3 crystal. The Mg-doped sample could be operated from zero up to more than 1000 V biasing level. The recorded electric signal and energy histograms were investigated. [ABSTRACT FROM AUTHOR]

In a recent commentary, J. M. Kosterlitz described how D. Thouless and he got motivated to investigate melting and suprafluidity in two dimensions [Kosterlitz JM (2016) J Phys Condens Matter 28:481001]. It was due to the lack of broken translational symmetry in two dimensions--doubting the existence of 2D crystals-- and the first computer simulations foretelling 2D crystals (at least in tiny systems). The lack of broken symmetries proposed by D. Mermin and H. Wagner is caused by long wavelength density fluctuations. Those fluctuations do not only have structural impact, but additionally a dynamical one: They cause the Lindemann criterion to fail in 2D in the sense that the mean squared displacement of atoms is not limited. Comparing experimental data from 3D and 2D amorphous solids with 2D crystals, we disentangle Mermin-Wagner fluctuations from glassy structural relaxations. Furthermore, we demonstrate with computer simulations the logarithmic increase of displacements with system size: Periodicity is not a requirement for Mermin-Wagner fluctuations, which conserve the homogeneity of space on long scales. [ABSTRACT FROM AUTHOR]

The objective of this study was to document and review advances and groundbreaking progress in cardiac and body MR at ultrahigh fields (UHF, B0 ≥ 7.0 T) with the goal to attract talent, clinical adopters, collaborations and resources to the biomedical and diagnostic imaging communities. This review surveys traits, advantages and challenges of cardiac and body MR at 7.0 T. The considerations run the gamut from technical advances to clinical opportunities. Key concepts, emerging technologies, practical considerations, frontier applications and future directions of UHF body and cardiac MR are provided. Examples of UHF cardiac and body imaging strategies are demonstrated. Their added value over the kindred counterparts at lower fields is explored along with an outline of research promises. The achievements of cardiac and body UHF-MR are powerful motivators and enablers, since extra speed, signal and imaging capabilities may be invested to overcome the fundamental constraints that continue to hamper traditional cardiac and body MR applications. If practical obstacles, concomitant physics effects and technical impediments can be overcome in equal measure, sophisticated cardiac and body UHF-MR will help to open the door to new MRI and MRS approaches for basic research and clinical science, with the lessons learned at 7.0 T being transferred into broad clinical use including diagnostics and therapy guiding at lower fields. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the framework of the I_SMART project the main aim is to develop an innovative radiation detection system based on silicon carbide technology in view to detect neutrons (thermal and fast) and photons for harsh environments. In the present work two geometries have been realized based on ion implantation of boron. In the first geometry, 10B ions have been implanted into the Al metallic contact of a p-n diode to create the neutron converter layer. In the second geometry one single process has been used to realize both the p+-layer and the neutron converter layer. The technological processes followed to fabricate these detectors, with a study of their electrical behavior and their responses under thermal neutron irradiations are addressed in this paper. [ABSTRACT FROM PUBLISHER]

In the framework of the European I-Smart project, optimal 4H-SiC based diode geometries were developed for high temperature neutron detection. Irradiation tests were conducted with 14 MeV fast neutrons supplied by a deuterium-tritium neutron generator with an average neutron yield of 4.04 \times 10^10 - 5.25 \times 10^10\;\n/s at Neutron Laboratory of the Technical University of Dresden in Germany. In this paper, we interpret the first measurements and results with 4H-SiC detector irradiated with fast neutrons from room temperature up to 500 °C. These experiments are serving also the first simulation of the harsh environmental condition measurements in the tritium breeding blanket of the ITER fusion reactor, which is one of the most prominent planned location of high temperature neutron flux characterization studies in the near future. [ABSTRACT FROM PUBLISHER]

Renal tissue hypoperfusion and hypoxia are key elements in the pathophysiology of acute kidney injury and its progression to chronic kidney disease. Yet, in vivo assessment of renal haemodynamics and tissue oxygenation remains a challenge. Many of the established approaches are invasive, hence not applicable in humans. Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) offers an alternative. BOLD-MRI is non-invasive and indicative of renal tissue oxygenation. Nonetheless, recent (pre-) clinical studies revived the question as to how bold renal BOLD-MRI really is. This review aimed to deliver some answers. It is designed to inspire the renal physiology, nephrology and imaging communities to foster explorations into the assessment of renal oxygenation and haemodynamics by exploiting the powers of MRI. For this purpose, the specifics of renal oxygenation and perfusion are outlined. The fundamentals of BOLD-MRI are summarized. The link between tissue oxygenation and the oxygenation-sensitive MR biomarker [ABSTRACT FROM AUTHOR]

Purpose: This study examines the subjective acceptance during UHF-CMR in a cohort of healthy volunteers who underwent a cardiac MR examination at 7.0T. Methods: Within a period of two-and-a-half years (January 2012 to June 2014) a total of 165 healthy volunteers (41 female, 124 male) without any known history of cardiac disease underwent UHF-CMR. For the assessment of the subjective acceptance a questionnaire was used to examine the participants experience prior, during and after the UHF-CMR examination. For this purpose, subjects were asked to respond to the questionnaire in an exit interview held immediately after the completion of the UHF-CMR examination under supervision of a study nurse to ensure accurate understanding of the questions. All questions were answered with “yes” or “no” including space for additional comments. Results: Transient muscular contraction was documented in 12.7% of the questionnaires. Muscular contraction was reported to occur only during periods of scanning with the magnetic field gradients being rapidly switched. Dizziness during the study was reported by 12.7% of the subjects. Taste of metal was reported by 10.1% of the study population. Light flashes were reported by 3.6% of the entire cohort. 13% of the subjects reported side effects/observations which were not explicitly listed in the questionnaire but covered by the question about other side effects. No severe side effects as vomiting or syncope after scanning occurred. No increase in heart rate was observed during the UHF-CMR exam versus the baseline clinical examination. Conclusions: This study adds to the literature by detailing the subjective acceptance of cardiovascular magnetic resonance imaging examinations at a magnetic field strength of 7.0T. Cardiac MR examinations at 7.0T are well tolerated by healthy subjects. Broader observational and multi-center studies including patient cohorts with cardiac diseases are required to gain further insights into the subjective acceptance of UHF-CMR examinations. [ABSTRACT FROM AUTHOR]

Purpose This work proposes a dual contrast rapid acquisition with relaxation enhancement (RARE) variant (2in1-RARE), which provides simultaneous proton density (PD) and T2* contrast in a single acquisition. Theory and Methods The underlying concept of 2in1-RARE is the strict separation of spin echoes and stimulated echoes. This approach offers independent weighting of spin echoes and stimulated echoes. 2in1-RARE was evaluated in phantoms including signal-to-noise ratio (SNR) and point spread function assessment. 2in1-RARE was benchmarked versus coherent RARE and a split-echo RARE variant. The applicability of 2in1-RARE for brain imaging was demonstrated in a small cohort of healthy subjects (n = 10) and, exemplary, a multiple sclerosis patient at 3 Tesla as a precursor to a broader clinical study. Results 2in1-RARE enables the simultaneous acquisition of dual contrast weighted images without any significant image degradation and without sacrificing SNR versus split-echo RARE. This translates into a factor of two speed gain over multi-contrast, sequential split-echo RARE. A 15% broadening of the point spread function was observed in 2in1-RARE. T1 relaxation effects during the mixing time can be neglected for brain tissue. Conclusion 2in1-RARE offers simultaneous acquisition of images of anatomical (PD) and functional (T2*) contrast. It presents an alternative to address scan time constraints frequently encountered during sequential acquisition of T2* or PD-weighted RARE. Magn Reson Med 72:1590-1598, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]