67 research outputs found

    Interpretative and predictive modelling of Joint European Torus collisionality scans

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    Transport modelling of Joint European Torus (JET) dimensionless collisionality scaling experiments in various operational scenarios is presented. Interpretative simulations at a fixed radial position are combined with predictive JETTO simulations of temperatures and densities, using the TGLF transport model. The model includes electromagnetic effects and collisions as well as □(→┬E ) X □(→┬B ) shear in Miller geometry. Focus is on particle transport and the role of the neutral beam injection (NBI) particle source for the density peaking. The experimental 3-point collisionality scans include L-mode, and H-mode (D and H and higher beta D plasma) plasmas in a total of 12 discharges. Experimental results presented in (Tala et al 2017 44th EPS Conf.) indicate that for the H-mode scans, the NBI particle source plays an important role for the density peaking, whereas for the L-mode scan, the influence of the particle source is small. In general, both the interpretative and predictive transport simulations support the experimental conclusions on the role of the NBI particle source for the 12 JET discharges

    Overview of JET results for optimising ITER operation

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    The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle (α) physics in the coming D–T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER

    Overview of JET results for optimising ITER operation

    Get PDF
    The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle (α) physics in the coming D–T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER

    A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors

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    The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices

    Clinical guidance for Radioiodine Refractory Differentiated Thyroid Cancer

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    Prognosis from differentiated thyroid cancer is worse when the disease becomes refractory to radioiodine. Until recently, treatment options have been limited to local therapies such as surgery and radiotherapy, but the recent availability of systemic therapies now provides some potential for disease control. Multi-targeted kinase inhibitors (TKIs) including lenvatinib and sorafenib have been shown to improve progression free survival in Phase III clinical trials, but are also associated with a spectrum of adverse effects. Other TKIs have been utilised as "redifferentiation" agents, increasing sodium iodide symporter expression in metastases and thus restoring radioiodine avidity. Some patients whose disease progresses on initial TKI therapy will still respond to a different TKI and clinical trials currently in progress will clarify the best options for such patients. As these drugs are not inexpensive, care needs to be taken to minimize not only biological but also financial toxicity. In this review we examine the basic biology of radioiodine refractory disease, and discuss optimal treatment approaches, with specific focus on choice and timing of TKI treatment. This clinical field remains fluid, and directions for future research include exploring biomarkers and considering adjuvant TKI use in certain patient groups. This article is protected by copyright. All rights reserved

    New era: Prophylactic surgery for patients with multiple endocrine neoplasia-2A

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    Background: The surgical management of patients with multiple endocrine neoplasia-2A (MEN-2A) continues to evolve with specific genotype-phenotype correlations allowing for a more tailored approach. In this study, we report the surgical management of one of the largest MEN-2A families with a rearranged during transfection (RET) codon 804 mutation. Method: This is a cohort study comprising all at-risk kindred within a single known MEN-2A family. Prophylactic total thyroidectomy with lymph node dissection was recommended to all mutation carriers aged 5 years and older. Results: There were a total of 48 at-risk individuals in the MEN-2A kindred, with 22 patients undergoing thyroidectomy after appropriate preoperative evaluation. A total of 9 patients had medullary thyroid cancer including 5 with a normal preoperative calcitonin level. A total of 11 patients had C-cell hyperplasia and 7 showed histological evidence of parathyroid disease. Only the index case had a phaeochromocytoma. Conclusion: Genetic testing for germline mutations in the RET proto-oncogene has allowed precise identification of affected RET carriers and provided the opportunity for prophylactic or 'preclinical' surgery to treat and in fact to prevent medullary thyroid cancer. This concept of prophylactic surgery based on a genetic test is likely to be applied more widely as the tools of molecular biology advance
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