| 1. |
- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
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| 5. |
- Labit, B., et al.
(författare)
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Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:8
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 Institute of Physics Publishing. All rights reserved. Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle the role of plasma fueling and plasma shape for the onset of small ELM regimes. On both devices, small ELM regimes with high confinement are achieved if and only if two conditions are fulfilled at the same time. Firstly, the plasma density at the separatrix must be large enough (ne,sep/nG ∼ 0.3), leading to a pressure profile flattening at the separatrix, which stabilizes type-I ELMs. Secondly, the magnetic configuration has to be close to a double null (DN), leading to a reduction of the magnetic shear in the extreme vicinity of the separatrix. As a consequence, its stabilizing effect on ballooning modes is weakened.
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| 6. |
- Stroth, U., et al.
(författare)
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Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development
- 2022
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 62:4
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Tidskriftsartikel (refereegranskat)abstract
- An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L-H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced D α H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts.
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| 7. |
- Meyer, H.F., et al.
(författare)
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Overview of physics studies on ASDEX Upgrade
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance the physics base of ITER and DEMO. Here, the full tungsten wall is a key asset for extrapolating to future devices. The high overall heating power, flexible heating mix and comprehensive diagnostic set allows studies ranging from mimicking the scrape-off-layer and divertor conditions of ITER and DEMO at high density to fully non-inductive operation (q 95 = 5.5, ) at low density. Higher installed electron cyclotron resonance heating power 6 MW, new diagnostics and improved analysis techniques have further enhanced the capabilities of AUG. Stable high-density H-modes with MW m-1 with fully detached strike-points have been demonstrated. The ballooning instability close to the separatrix has been identified as a potential cause leading to the H-mode density limit and is also found to play an important role for the access to small edge-localized modes (ELMs). Density limit disruptions have been successfully avoided using a path-oriented approach to disruption handling and progress has been made in understanding the dissipation and avoidance of runaway electron beams. ELM suppression with resonant magnetic perturbations is now routinely achieved reaching transiently . This gives new insight into the field penetration physics, in particular with respect to plasma flows. Modelling agrees well with plasma response measurements and a helically localised ballooning structure observed prior to the ELM is evidence for the changed edge stability due to the magnetic perturbations. The impact of 3D perturbations on heat load patterns and fast-ion losses have been further elaborated. Progress has also been made in understanding the ELM cycle itself. Here, new fast measurements of and E r allow for inter ELM transport analysis confirming that E r is dominated by the diamagnetic term even for fast timescales. New analysis techniques allow detailed comparison of the ELM crash and are in good agreement with nonlinear MHD modelling. The observation of accelerated ions during the ELM crash can be seen as evidence for the reconnection during the ELM. As type-I ELMs (even mitigated) are likely not a viable operational regime in DEMO studies of 'natural' no ELM regimes have been extended. Stable I-modes up to have been characterised using -feedback. Core physics has been advanced by more detailed characterisation of the turbulence with new measurements such as the eddy tilt angle - measured for the first time - or the cross-phase angle of and fluctuations. These new data put strong constraints on gyro-kinetic turbulence modelling. In addition, carefully executed studies in different main species (H, D and He) and with different heating mixes highlight the importance of the collisional energy exchange for interpreting energy confinement. A new regime with a hollow profile now gives access to regimes mimicking aspects of burning plasma conditions and lead to nonlinear interactions of energetic particle modes despite the sub-Alfvénic beam energy. This will help to validate the fast-ion codes for predicting ITER and DEMO.
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| 8. |
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| 9. |
- He, W., et al.
(författare)
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CYP2D6 genotype predicts tamoxifen discontinuation and drug response : a secondary analysis of the KARISMA trial
- 2021
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534. ; 32:10, s. 1286-1293
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Tidskriftsartikel (refereegranskat)abstract
- Background: Guidelines regarding whether tamoxifen should be prescribed based on women's cytochrome P450 2D6 (CYP2D6) genotypes are conflicting and have caused confusion. This study aims to investigate if CYP2D6 metabolizer status isa associated with tamoxifen-related endocrine symptoms, tamoxifen discontinuation, and mammographic density change. Patients and methods: We used data from 1440 healthy women who participated the KARISMA dose determination trial. Endocrine symptoms were measured using a modified Functional Assessment of Cancer Therapy – Endocrine Symptoms (FACT-ES) questionnaire. Change in mammographic density was measured and used as a proxy for tamoxifen response. Participants were genotyped and categorized as poor, intermediate, normal, or ultrarapid CYP2D6 metabolizers. Results: The median endoxifen level per mg oral tamoxifen among poor, intermediate, normal and ultrarapid CYP2D6 metabolizers were 0.18 ng/ml, 0.38 ng/ml, 0.56 ng/ml and 0.67 ng/ml, respectively. Ultrarapid CYP2D6 metabolizers were more likely than other groups to report a clinically relevant change in cold sweats, hot flash, mood swings, being irritable, as well as the overall modified FACT-ES score, after taking tamoxifen. The 6-month tamoxifen discontinuation rates among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were 25.7%, 23.6%, 28.6%, and 44.4%, respectively. Among those who continued and finished the 6-month tamoxifen intervention, the mean change in dense area among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were −0.8 cm2, −4.5 cm2, −4.1 cm2, and −8.0 cm2 respectively. Conclusions: Poor CYP2D6 metabolizers are likely to experience an impaired response to tamoxifen, measured through mammographic density reduction. In contrast, ultrarapid CYP2D6 metabolizers are at risk for exaggerated response with pronounced adverse effects that may lead to treatment discontinuation.
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| 10. |
- Bull, Peter, et al.
(författare)
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Förstudie obemannade farkoster
- 2012
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Rapport (populärvet., debatt m.m.)abstract
- Obemannade farkoster används allt oftare, och i allt fler roller, i dagens kon- flikter. Denna rapport ger en bred överblick över området militära obemannade farkoster, samt rekommendationer för inriktningen av framtida FoU-satsningar inom området.Överblicken över området har fokus på både system, förmågor och verksam- heter som är relevanta för Försvarsmakten. Genom att låta de insatsförmågor som definieras i FMUP (Försvarsmaktens utvecklingsplan) gå som en röd tråd genom rapporten, både när specifika system diskuteras och när möjliga scena- rier där obemannade farkoster kan vara till nytta beskrivs, har vi försökt hålla både bredd och relevans i dokumentet.Rekommendationerna vilar på en genomgång av de inriktningsdokument som producerats i Försvarsmakten, t.ex. Perspektivplanneringen och FMUP, besök vid de enheter som dagligen använder obemannade farkoster, UAV-enheten i Karlsborg och Swedec i Eksjö, samt den områdesöverblick som nämns ovan. Slutsatserna är att den effektivaste kompetensuppbyggnaden och kunskapsöver- föringen fås om man skapar breda tvärvetenskapliga projekt inom respektive systemkategori (UAV, UGV, etc) med nära kontakter till materielförsörjnings- processen och perspektivplaneringen. Dessa kan samla kompetensen inom FHS och FOI, övervaka forskningsfronten genom att bevaka tävlingar, konferenser samt delta i internationella samarbeten, samt överföra det samlade resultaten till Försvarsmakten genom demonstrationer av verkliga eller simulerade delsy- stem och interaktiva simuleringar av hela system. Just systemsimuleringar kan göras särskilt realistiska, eftersom interaktionen med de riktiga obemannade systemen till stor del sker igenom kontrollstationernas datorer. På så sätt ska- pas en känsla för både hot och möjligheter med de nya systemen, vilket gagnar både taktikutveckling och materielprocesser.
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| 11. |
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| 15. |
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| 16. |
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| 17. |
- Krieger, K., et al.
(författare)
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Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade
- 2017
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Ingår i: Physica Scripta. - : IOP PUBLISHING LTD. - 0031-8949 .- 1402-4896. ; T170
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Tidskriftsartikel (refereegranskat)abstract
- Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in the tokamak experiment ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the Divertor Manipulator II system. The exposed sample was designed with an elevated sloped surface inclined against the incident magnetic field to increase the projected parallel power flux to a level were transient melting by ELMs would occur. Sample exposure was controlled by moving the outer strike point to the sample location. As extension to previous melt studies in the new experiment both the current flow from the sample to vessel potential and the local surface temperature were measured with sufficient time resolution to resolve individual ELMs. The experiment provided for the first time a direct link of current flow and surface temperature during transient ELM events. This allows to further constrain the MEMOS melt motion code predictions and to improve the validation of its underlying model assumptions. Post exposure ex situ analysis of the retrieved samples confirms the decreased melt motion observed at shallower magnetic field line to surface angles compared to that at leading edges exposed to the parallel power flux.
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| 18. |
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| 19. |
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| 20. |
- Reddel, H. K., et al.
(författare)
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Effect of different asthma treatments on risk of cold-related exacerbations
- 2011
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 38:3, s. 584-593
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Tidskriftsartikel (refereegranskat)abstract
- Common colds often trigger asthma exacerbations. The present study compared cold-related severe exacerbations during budesonide/formoterol maintenance and reliever therapy, and different regimens of maintenance inhaled corticosteroids (ICS), with or without long-acting beta(2)-agonists (LABA), and with as-needed short-acting beta(2)-agonists (SABA) or LABA. Reported colds and severe exacerbations (defined by oral corticosteroid use and/or hospitalisation/emergency room visit) were assessed for 12,507 patients during 6-12 months of double-blind treatment. Exacerbations occurring <= 14 days after onset of reported colds were analysed by a Poisson model. The incidence of colds was similar across treatments. Asthma symptoms and reliever use increased during colds. Budesonide/formoterol maintenance and reliever therapy reduced severe cold-related exacerbations by 36% versus pooled comparators plus SABA (rate ratio (RR) 0.64; p=0.002), and for individual treatment comparisons, by 52% versus the same maintenance dose of ICS/LABA (RR 0.48; p < 0.001); there were nonsignificant reductions versus higher maintenance doses of ICS or ICS/LABA (RR 0.83 and 0.72, respectively). As-needed LABA did not reduce cold-related exacerbations versus as-needed SABA (RR 0.96). Severe cold-related exacerbations were reduced by budesonide/formoterol maintenance and reliever therapy compared with ICS with or without LABA and with as-needed SABA. Subanalyses suggested the importance of the ICS component in reducing cold-related exacerbations. Future studies should document the cause of exacerbations, in order to allow identification of different treatment effects.
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| 21. |
- Sjöblom, K, et al.
(författare)
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Patient evaluation of a new injection pen for growth hormone treatment in children and adults.
- 1995
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Ingår i: Acta paediatrica (Oslo, Norway : 1992). Supplement. - : Wiley. - 0803-5326 .- 0803-5253 .- 1651-2227. ; 411, s. 63-5
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate patients' perception and acceptance of a new multi-dose injection device (Genotropin Pen) for recombinant growth hormone (GH) supplied in a two-chamber cartridge. The pen is combined with a very thin needle (B-D Microfine + (29 G) and meets future demands when dosing of GH will be changed from International Units (IU) to milligrams (mg). A total of 39 children receiving GH treatment (East Hospital, Gothenburg and St Bartholomew's Hospital, London), aged between 7 and 17 years, and 39 GH-treated adults (Sahlgrenska Hospital, Gothenburg and Karolinska Hospital, Stockholm), aged between 20 and 68 years, participated in the study. The daily dose ranged from 0.3 mg to 2.6 mg. The injections were given subcutaneously, once daily, and most of the patients used the thigh as an injection site. After a trial period of 2 weeks, injection technique, pain, fear of injection and convenience of the Genotropin Pen were compared with the experience with the prestudy device (Genotropin KabiPen 16, 16(8) or 36) by questionnaire. A total of 95% of the patients preferred the Genotropin Pen to the prestudy device for the following reasons: a greater certainty of correct dosing with the digital display; the possibility of correcting the set dose; the lock function of the injection button when injection is complete; more comfortable to hold due to the design and the plastic material; and reduced pain when injecting due to the thinner needles. Four patients (5%) preferred the prestudy device KabiPen as they considered this to be 'good enough'. Thus, the Genotropin Pen is a convenient injection device and most patients prefer it to the KabiPen.
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| 25. |
- Ablikim, M., et al.
(författare)
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Determination of spin and parity of D*ˆ—(s) mesons
- 2023
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 846
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Tidskriftsartikel (refereegranskat)abstract
- The spin and parity of the charmed mesons D*s+, D*0 and D*+ are determined for the first time to be JP = 1- with significances greater than 10σ over other hypotheses of 2+ and 3-, using an e+e- collision data sample with an integrated luminosity of 3.19 fb-1 collected by the BESIII detector at a center-of-mass energy of 4.178 GeV. Different spin-parity hypotheses are tested via a helicity amplitude analysis of the processes e+e--→ D*s+ D-s, D*0D0 and D*+D-, with D∗+s → D*+s γ, D∗0 → D0π0 , and D∗+ → D+π0. The results confirm the quark model predictions
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