| 1. |
- Bombarda, F., et al.
(författare)
-
Runaway electron beam control
- 2019
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
-
Tidskriftsartikel (refereegranskat)
|
|
| 2. |
-
- 2018
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
-
Forskningsöversikt (refereegranskat)
|
|
| 3. |
- Labit, B., et al.
(författare)
-
Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade
- 2019
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:8
-
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.
|
|
| 4. |
- Meyer, H., et al.
(författare)
-
Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
-
Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 5. |
- Guastalla, G., et al.
(författare)
-
Analysis and Results of the 104Sn Coulomb Excitation Experiment
- 2014
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 533:1
-
Konferensbidrag (refereegranskat)abstract
- The analysis of the Coulomb excitation experiment conducted on 104Sn required a strict selection of the data in order to reduce the large background present in the gamma-ray energy spectra and identify the gamma-ray peak corresponding to the Coulomb excitation events. As a result the B(E2; 0 + -> 2+) value could be extracted, which established the downward trend towards 100Sn and therefore the robustness of the N=Z=50 core against quadrupole excitations.
|
|
| 6. |
- Beutier, G., et al.
(författare)
-
Band Filling Control of the Dzyaloshinskii-Moriya Interaction in Weakly Ferromagnetic Insulators
- 2017
-
Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:16
-
Tidskriftsartikel (refereegranskat)abstract
- We observe and explain theoretically a dramatic evolution of the Dzyaloshinskii-Moriya interaction (DMI) in the series of isostructural weak ferromagnets, MnCO3, FeBO3, CoCO3, and NiCO3. The sign of the interaction is encoded in the phase of the x-ray magnetic diffraction amplitude, observed through interference with resonant quadrupole scattering. We find very good quantitative agreement with first-principles electronic structure calculations, reproducing both sign and magnitude through the series, and propose a simplified "toy model" to explain the change in sign with 3d shell filling. The model gives insight into the evolution of the DMI in Mott and charge transfer insulators.
|
|
| 7. |
- Dzhambov, Angel M., et al.
(författare)
-
Multiple pathways link urban green- and bluespace to mental health in young adults
- 2018
-
Ingår i: Environmental Research. - : Elsevier. - 0013-9351 .- 1096-0953. ; 166, s. 223-233
-
Tidskriftsartikel (refereegranskat)abstract
- Background: A growing body of scientific literature indicates that urban green- and bluespace support mental health; however, little research has attempted to address the complexities in likely interrelations among the pathways through which benefits plausibly are realized. Objectives: The present study examines how different plausible pathways between green/bluespace and mental health can work together. Both objective and perceived measures of green- and bluespace are used in these models. Methods: We sampled 720 students from the city of Plovdiv, Bulgaria. Residential greenspace was measured in terms of the Normalized Difference Vegetation Index (NDVI), tree cover density, percentage of green areas, and Euclidean distance to the nearest green space. Bluespace was measured in terms of its presence in the neighborhood and the Euclidean distance to the nearest bluespace. Mental health was measured with the 12-item form of the General Health Questionnaire (GHQ-12). The following mediators were considered: perceived neighborhood green/bluespace, restorative quality of the neighborhood, social cohesion, physical activity, noise and air pollution, and environmental annoyance. Structural equation modelling techniques were used to analyze the data. Results: Higher NDVI within a 300 m buffer around the residence was associated with better mental health through higher perceived greenspace; through higher perceived greenspace, leading to increased restorative quality, and subsequently to increased physical activity (i.e., serial mediation); through lower noise exposure, which in turn was associated with lower annoyance; and through higher perceived greenspace, which was associated with lower annoyance. Presence of bluespace within a 300 m buffer did not have a straightforward association with mental health owing to competitive indirect paths: one supporting mental health through higher perceived bluespace, restorative quality, and physical activity; and another engendering mental ill-health through higher noise exposure and annoyance. Conclusions: We found evidence that having more greenspace near the residence supported mental health through several indirect pathways with serial components. Conversely, bluespace was not clearly associated with mental health.
|
|
| 8. |
- Dzhambov, Angel M., et al.
(författare)
-
Residential greenspace is associated with mental health via intertwined capacity-building and capacity-restoring pathways
- 2019
-
Ingår i: Environmental Research. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0013-9351 .- 1096-0953. ; 178
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Experiences afforded by natural settings promote health by helping people to build new adaptive capacities and to restore existing capacities. The aim of this study was to examine relations among restorative experience, mindfulness, rumination and psychological resilience in pathways linking residential greenspace to anxiety and depression symptoms.Methods: We sampled 529 university students residing in Plovdiv, Bulgaria. Residential greenspace was measured in terms of the Normalized Difference Vegetation Index (NDVI) and tree cover density for different buffer sizes. Symptoms of anxiety and depression were measured with the Generalized Anxiety Disorder scale (7-item) and Patient Health Questionnaire (9-item), respectively. The following mediators were assessed by self-report: perceived greenspace, restorative quality of the neighborhood, dispositional mindfulness, rumination, and psychological resilience. Structural equation modelling techniques were used to test the theoretically-indicated relations among the variables.Results: Across different buffer sizes, higher greenspace was consistently associated with reduced scores on the anxiety and depression scales. This effect was partially mediated via several pathways. Specifically, higher NDVI500-m was associated with higher perceived greenspace, and in turn, with higher restorative quality, and then with higher mindfulness, lower rumination, and greater resilience to stress, and consequently, with better mental health.Conclusions: Our findings affirm the potential of greenspace for building psychological resilience and promoting health by offsetting dysfunctional rumination and facilitating mindfulness as components of intertwined capacity-building and capacity-restoring pathways.
|
|
| 9. |
- Pincini, D., et al.
(författare)
-
Role of the orbital moment in a series of isostructural weak ferromagnets
- 2018
-
Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 98:10
-
Tidskriftsartikel (refereegranskat)abstract
- The orbital contribution to the magnetic moment of the transition-metal ion in the isostructural weak ferromagnets ACO(3) (A = Mn,Co,Ni) and FeBO3 was investigated by a combination of first-principles calculations, nonresonant x-ray magnetic scattering, and x-ray magnetic circular dichroism. A nontrivial evolution of the orbital moment as a function of the 3d orbitals filling is revealed, with a particularly large value found in the Co member of the family. Here, the coupling between magnetic and lattice degrees of freedom produced by the spin-orbit interaction results in a large single-ion anisotropy and a peculiar magnetic-moment-induced electron cloud distortion, evidenced by the appearance of a subtle scattering amplitude at space-group-forbidden reflections and significant magnetostrictive effects. Our results, which complement a previous investigation on the sign of the Dzyaloshinskii-Moriya interaction across the series, highlight the importance of spin-orbit coupling in the physics of weak ferromagnets and prove the ability of modern first-principles calculations to predict the properties of materials where the Dzyaloshinskii-Moriya interaction is a fundamental ingredient of the magnetic Hamiltonian.
|
|
