1. |
- Aad, G., et al.
(author)
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- 2015
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In: Journal of High Energy Physics. - : Springer-Verlag New York. - 1029-8479 .- 1126-6708. ; :5
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Journal article (peer-reviewed)
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2. |
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- 2018
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Research review (peer-reviewed)
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3. |
- Bombarda, F., et al.
(author)
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Runaway electron beam control
- 2019
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In: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Journal article (peer-reviewed)
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4. |
- Meyer, H.F., et al.
(author)
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Overview of physics studies on ASDEX Upgrade
- 2019
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Research review (peer-reviewed)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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5. |
- Meyer, H., et al.
(author)
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Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
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In: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
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Journal article (peer-reviewed)abstract
- Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.
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6. |
- Meyer, H., et al.
(author)
-
Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
-
In: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
-
Journal article (peer-reviewed)abstract
- Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.
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7. |
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8. |
- Back, A., et al.
(author)
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Complexity metric based on fraction of penumbra dose - initial study
- 2017
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In: 9TH INTERNATIONAL CONFERENCE ON 3D RADIATION DOSIMETRY ; Journal of Physics Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596.
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Book chapter (other academic/artistic)abstract
- Volumetric modulated arc therapy improve radiotherapy outcome for many patients compared to conventional three dimensional conformal radiotherapy but require a more extensive, most often measurement based, quality assurance. Multi leaf collimator (MLC) aperture-based complexity metrics have been suggested to be used to distinguish complex treatment plans unsuitable for treatment without time consuming measurements. This study introduce a spatially resolved complexity score that correlate to the fraction of penumbra dose and will give information on the spatial distribution and the clinical relevance of the calculated complexity. The complexity metric is described and an initial study on the correlation between the complexity score and the difference between measured and calculated dose for 30 MLC openings is presented. The result of an analysis of the complexity scores were found to correlate to differences between measurements and calculations with a Pearson's r-value of 0.97.
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9. |
- Sarudis, Sebastian, 1981, et al.
(author)
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Systematic evaluation of lung tumor motion using four-dimensional computed tomography
- 2017
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In: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 56:4, s. 525-530
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Journal article (peer-reviewed)abstract
- Background: Respiratory-induced lung tumor motion may decrease robustness and outcome of radiation therapy (RT) if not accounted for. This study provides detailed information on the motion distribution of lung tumors for a group of 126 patients treated with stereotactic body RT.Material and methods: Four-dimensional computed tomography scans were reviewed to assess lung tumor motion. The tumor motion was determined by the center of mass shift based on a rigid registration of the breathing phases containing the largest positional differences in the inferior-superior (IS), left-right (LR), and anterior-posterior (AP) directions. The patients were divided into subgroups depending on tumor diameter (<2.0cm, 2.05.0cm, phi>5.0cm) and tumor location within the lung (upper, middle, or lower lobe). The observed motion distributions were evaluated for each group separately to assess the dependence on tumor size and location. For each tumor size, the motion pattern in each direction (IS, LR, and AP) was analyzed for every tumor moving>5mm. Sinusoidal trigonometric functions were fitted to the measured data using the least mean square method to determine which type of function best describes the motion pattern. Tumor volumes between 1.6 and 52.3cm(3) were evaluated. Mann-Whitney statistical tests were used for statistical analyses.Results: The mean amplitude for the tumors in this study was 1.5mm (LR), 2.5mm (AP), and 6.9mm (IS) while the maximum amplitude was 11.0mm (LR), 9.0mm (AP), and 53.0mm (IS). In total, 95% of the tumors moved 20mm in the IS direction, 3mm in the LR direction, and 6mm in the AP direction. The observed motion distributions showed no statistically significant correlation with tumor size or location within the lung except for motion in the IS direction, where the mean and maximum amplitudes significantly increased for tumors located in the middle and lower parts of the lung. The motion pattern of a tumor in any direction was best described using a squared trigonometric function of the type where A is the maximum amplitude of the motion in the current direction, t is the time of measurement, T is the total time of the breathing cycle and B is a constant used to synchronize the starting point of the breathing cycle.Conclusion: Lung tumor movements were generally larger in the IS direction and the motion amplitude in this direction increased for tumors located in the middle and lower parts of the lungs. Motions in LR or AP showed no such relation. Tumor size was not found to have any correlation with the motion amplitude in any direction. The motion pattern of a lung tumor in any direction is best described with a squared sinusoidal function independently of the tumor size or tumor location.
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10. |
- Schaberg, T, et al.
(author)
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[Tuberculosis Guideline for Adults - Guideline for Diagnosis and Treatment of Tuberculosis including LTBI Testing and Treatment of the German Central Committee (DZK) and the German Respiratory Society (DGP)]
- 2017
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In: Pneumologie (Stuttgart, Germany). - : Georg Thieme Verlag KG. - 1438-8790 .- 0934-8387. ; 71:6, s. 325-397
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Journal article (peer-reviewed)abstract
- In Deutschland ist seit 2015 ein deutlicher Anstieg der gemeldeten Tuberkulosefälle zu verzeichnen. Zurückzuführen ist dieser vor allem auf die aktuell vermehrte Migration. Durch die niedrige Inzidenz in den vorhergehenden Jahren konzentriert sich die Erfahrung im Umgang mit Tuberkulose immer mehr auf spezialisierte Zentren. Pneumologen wie auch andere Fachbereiche sind nun aber wieder häufiger an der Behandlung einer Tuberkulose beteiligt, sodass Fachwissen zur Standardtherapie wie auch zu selteneren Therapiesituationen benötigt wird. Die aktuelle Leitlinie zur Diagnostik und Therapie, einschließlich Chemoprävention und -prophylaxe im Erwachsenenalter fasst den derzeitigen Wissensstand zusammen und passt die Empfehlungen an die Situation in Deutschland an. Realisiert wurde die AWMF S2k-Leitlinie durch das Deutsche Zentralkomitee zur Bekämpfung der Tuberkulose e. V. (DZK) im Auftrag der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin e. V. (DGP). Zur Behandlung der Tuberkulose im pädiatrischen Bereich wird in Kürze eine eigenständige Leitlinie der entsprechenden Fachgesellschaften veröffentlicht. Im Vergleich zu den Empfehlungen von 2012 sind eigenständige Kapitel zur Labordiagnostik und zum therapeutischen Medikamentenmanagement entstanden. Die Kapitel Mehrfachresistenzen gegen Medikamente der Standardtherapie, HIV-Koinfektion und die Übersicht der Arzneimittel wurden erweitert. Die umfangreiche Überarbeitung der Empfehlungen soll Ärzten und auch anderen Beschäftigten im Gesundheitswesen helfen, den aktuellen Herausforderungen im Umgang mit dem selten gewordenen Tuberkuloseerreger zu begegnen.
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