| 1. |
- Fenstermacher, M.E., et al.
(författare)
-
DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy
- 2022
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 62:4
-
Tidskriftsartikel (refereegranskat)abstract
- DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance core and boundary plasmas. Substantial increases in off-axis current drive efficiency from an innovative top launch system for EC power, and in pressure broadening for Alfven eigenmode control from a co-/counter-I p steerable off-axis neutral beam, all improve the prospects for optimization of future long pulse/steady state high performance tokamak operation. Fundamental studies into the modes that drive the evolution of the pedestal pressure profile and electron vs ion heat flux validate predictive models of pedestal recovery after ELMs. Understanding the physics mechanisms of ELM control and density pumpout by 3D magnetic perturbation fields leads to confident predictions for ITER and future devices. Validated modeling of high-Z shattered pellet injection for disruption mitigation, runaway electron dissipation, and techniques for disruption prediction and avoidance including machine learning, give confidence in handling disruptivity for future devices. For the non-nuclear phase of ITER, two actuators are identified to lower the L-H threshold power in hydrogen plasmas. With this physics understanding and suite of capabilities, a high poloidal beta optimized-core scenario with an internal transport barrier that projects nearly to Q = 10 in ITER at ∼8 MA was coupled to a detached divertor, and a near super H-mode optimized-pedestal scenario with co-I p beam injection was coupled to a radiative divertor. The hybrid core scenario was achieved directly, without the need for anomalous current diffusion, using off-axis current drive actuators. Also, a controller to assess proximity to stability limits and regulate β N in the ITER baseline scenario, based on plasma response to probing 3D fields, was demonstrated. Finally, innovative tokamak operation using a negative triangularity shape showed many attractive features for future pilot plant operation.
|
|
| 2. |
- Abe, K., et al.
(författare)
-
Neutron tagging following atmospheric neutrino events in a water Cherenkov detector
- 2022
-
Ingår i: Journal of Instrumentation. - : Institute of Physics (IOP). - 1748-0221. ; 17:10
-
Tidskriftsartikel (refereegranskat)abstract
- We present the development of neutron-tagging techniques in Super-Kamiokande IV using a neural network analysis. The detection efficiency of neutron capture on hydrogen is estimated to be 26%, with a mis-tag rate of 0.016 per neutrino event. The uncertainty of the tagging efficiency is estimated to be 9.0%. Measurement of the tagging efficiency with data from an Americium-Beryllium calibration agrees with this value within 10%. The tagging procedure was performed on 3,244.4 days of SK-IV atmospheric neutrino data, identifying 18,091 neutrons in 26,473 neutrino events. The fitted neutron capture lifetime was measured as 218 +/- 9 mu s.
|
|
| 3. |
- Obers, Niels A., et al.
(författare)
-
Quantum gravity phenomenology at the dawn of the multi-messenger era—A review
- 2022
-
Ingår i: Progress in Particle and Nuclear Physics. - : Elsevier BV. - 0146-6410 .- 1873-2224. ; 125
-
Forskningsöversikt (refereegranskat)abstract
- The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.
|
|
| 4. |
|
|
| 5. |
- Villanueva, G. L., et al.
(författare)
-
JWST molecular mapping and characterization of Enceladus’ water plume feeding its torus
- 2023
-
Ingår i: Nature Astronomy. - : Springer Nature. - 2397-3366. ; 7:9, s. 1056-1062
-
Tidskriftsartikel (refereegranskat)abstract
- Enceladus is a prime target in the search for life in our Solar System, having an active plume that is likely to be connected to a large liquid water sub-surface ocean. Using the sensitive near-infrared spectograph instrument on board the James Webb Space Telescope, we searched for organic compounds and characterized the plume’s composition and structure. The observations directly sample the fluorescence emissions of H2O and reveal an extraordinarily extensive plume (up to 10,000 km or 40 Enceladus radii) at cryogenic temperatures (25 K) embedded in a large bath of emission originating from Enceladus’ torus. Intriguingly, the observed outgassing rate (300 kg s−1) is similar to that derived from close-up observations with Cassini 15 years ago, and the torus density is consistent with previous spatially unresolved measurements with Herschel 13 years ago, which indicates that the vigour of gas eruption from Enceladus has been relatively stable over decadal timescales. This level of activity is sufficient to maintain a derived column density of 4.5 × 1017 m−2 for the embedding equatorial torus, and establishes Enceladus as the prime source of water across the Saturnian system. We performed searches for several non-water gases (CO2, CO, CH4, C2H6, CH3OH), but none were identified in the spectra. On the surface of the trailing hemisphere, we observe strong H2O ice features, including its crystalline form, yet we do not recover CO2, CO or NH3 ice signatures from these observations. As we prepare to send new spacecraft into the outer Solar System, these observations demonstrate the unique ability of the James Webb Space Telescope to provide critical support for the exploration of distant icy bodies and cryovolcanic plumes.
|
|
| 6. |
- Paganini, Anna, 1979, et al.
(författare)
-
A gender perspective on appearance-related concerns and its manifestations among persons born with unilateral cleft lip and palate
- 2021
-
Ingår i: Psychology Health & Medicine. - : Informa UK Limited. - 1354-8506 .- 1465-3966. ; 26:6, s. 771-778
-
Tidskriftsartikel (refereegranskat)abstract
- Cleft lip and palate (CLP) affects a person's facial appearance and can cause appearance-related distress. Appearance-related distress and its manifestations are not fully understood. Women with CLP tend to experience a higher degree of distress as well as undergo more aesthetic revisions than men. The aim of this study was to investigate if self-reported appearance-related gender differences occur among adults born with unilateral CLP using the Derriford Appearance Scale 24 (DAS24). One hundred sixty two consecutive patients, 107 men and 55 women, with unilateral CLP and no associated syndromes treated at the same hospital were asked to answer the DAS24. A mixed methods approach was used to analyse the questionnaires both quantitively and qualitatively. Fifty men and 30 women participated, the results showed that the aspects of appearance considered most disturbing was cleft-related among both genders, most common in regards to the nose. Three themes were found: acceptance, cleft features, and general appearance issues. The quantitative part showed that women reported higher appearance-related social anxiety and avoidance than men. This study demonstrated that appearance-related distress is present in both genders; however, women expressed more distress than men. Moreover, non-cleft as well as cleft features are of importance for self-reported dissatisfaction.
|
|
| 7. |
- Paganini, Anna, 1979, et al.
(författare)
-
Influence of Gender, Dispositional Optimism, and Coping Strategies on Appearance-Related Distress Among Swedish Adults With Cleft Lip and Palate
- 2022
-
Ingår i: Cleft Palate-Craniofacial Journal. - : SAGE Publications. - 1055-6656 .- 1545-1569. ; 59:6, s. 715-723
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the influence of gender, dispositional optimism, and coping strategies on appearance-related distress among individuals with unilateral cleft lip and palate (UCLP). Design: Cross-sectional design with self-report questionnaires analyzed primarily with Spearman correlations (r (s)) and multivariate regression analyses. Setting: A tertiary cleft center in Sweden. Participants: Eighty individuals with UCLP born 1966 to 1986. The mean age for men (n = 50) and women (n = 30) was 38.8 and 37.4 years, respectively. Main Outcome Measures: The Derriford Appearance Scale 24 measured appearance-related distress, the Life Orientation Test-Revised, short version measured dispositional optimism and pessimism, and the Coping Orientation to Problems Experienced, short version included 14 coping strategies. Results: Women had higher appearance-related distress than men, which was significantly (P < .05) related to self-blame (r (s) = 0.59), pessimism (r (s) = 0.59), and low optimism (r (s) = -0.56). Men's appearance-related distress was significantly associated with low active coping (r (s) = 0.35), low use of emotional support (r (s) = 0.29), denial (r (s) = 0.39), behavioral disengagement (r (s) = 0.41), and pessimism (r (s) = 0.28). The only significant gender interaction reflected greater impact of optimism in reducing appearance-related distress for women (beta = -0.06). Conclusions: This study showed that high levels of dispositional optimism decrease appearance-related distress, particularly for women. The coping strategies used differed between men and women, and the results suggest that both gender and psychosocial facto r (s) need to be considered in regard to appearance-related distress among individuals with UCLP in both clinical and research settings. A possible way to decrease distress is to strengthen positive coping strategies and dispositional optimism.
|
|
