| 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. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Cattaneo, C, et al.
(författare)
-
Simultaneous Onset of Haematological Malignancy and COVID: An Epicovideha Survey
- 2022
-
Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:22
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The outcome of patients with simultaneous diagnosis of haematological malignancies (HM) and COVID-19 is unknown and there are no specific treatment guidelines. Methods: We describe the clinical features and outcome of a cohort of 450 patients with simultaneous diagnosis of HM and COVID-19 registered in the EPICOVIDEHA registry between March 2020 to February 2022. Results: Acute leukaemia and lymphoma were the most frequent HM (35.8% and 35.1%, respectively). Overall, 343 (76.2%) patients received treatment for HM, which was delayed for longer than one month since diagnosis in 57 (16.6%). An overall response rate was observed in 140 (40.8%) patients after the first line of treatment. After a median follow-up of 35 days, overall mortality was 177/450 (39.3%); 30-day mortality was significantly higher in patients not receiving HM treatment (42.1%) than in those receiving treatment (27.4%, p = 0.004), either before and/or after COVID-19, or compared to patients receiving HM treatment at least after COVID-19 (15.2%, p < 0.001). Age, severe/critical COVID-19, ≥2 comorbidities, and lack of HM treatment were independent risk factors for mortality, whereas a lymphocyte count >500/mcl at COVID-19 onset was protective. Conclusions: HM treatment should be delivered as soon as possible for patients with simultaneous diagnosis of COVID-19 and HM requiring immediate therapy.
|
|
| 6. |
- Marchesi, F, et al.
(författare)
-
COVID-19 in adult acute myeloid leukemia patients: a long-term follow-up study from the European Hematology Association survey (EPICOVIDEHA)
- 2023
-
Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 108:1, s. 22-33
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with acute myeloid leukemia (AML) are at high risk of dying from coronavirus disease 2019 (COVID-19). The optimal management of AML patients with COVID-19 has not been established. Our multicenter study included 388 adult AML patients diagnosed with COVID-19 between February 2020 and October 2021. The vast majority were receiving or had received AML treatment in the preceding 3 months. COVID-19 was severe in 41.2% and critical in 21.1% of cases. The chemotherapeutic schedule was modified in 174 patients (44.8%), delayed in 68 and permanently discontinued in 106. After a median follow-up of 325 days, 180 patients (46.4%) had died; death was attributed to COVID-19 (43.3%), AML (26.1%) or to a combination of both (26.7%), whereas in 3.9% of cases the reason was unknown. Active disease, older age, and treatment discontinuation were associated with death, whereas AML treatment delay was protective. Seventy-nine patients had a simultaneous AML and COVID-19 diagnosis, with better survival when AML treatment could be delayed (80%; P<0.001). Overall survival in patients with a diagnosis of COVID-19 between January 2020 and August 2020 was significantly lower than that in patients diagnosed between September 2020 and February 2021 and between March 2021 and September 2021 (39.8% vs. 60% vs. 61.9%, respectively; P=0.006). COVID-19 in AML patients was associated with a high mortality rate and modifications of therapeutic algorithms. The best approach to improve survival was to delay AML treatment, whenever possible.
|
|
| 7. |
|
|
| 8. |
- Lanctot, M.J., et al.
(författare)
-
Measurement and modeling of three-dimensional equilibriua in DIII-D
- 2011
-
Ingår i: Physics of Plasmas. - 1089-7674 .- 1070-664X. ; 18, s. 056121-
-
Tidskriftsartikel (refereegranskat)abstract
- A detailed experiment-theory comparison reveals that linear ideal MHD theory is in quantitative agreement with external magnetic and internal soft x-ray measurements of the plasma response to externally applied non-axisymmetric fields over a broad range of beta and rotation. This result represents a significant step toward the goal of advancing the understanding of three-dimensional tokamak equilibria. Both the magnetic and soft x-ray measurements show the driven plasma perturbation increases linearly with the applied perturbation, suggesting the relevance of linear plasma response models. The magnetic and soft x-ray measurements are made at multiple toroidal and poloidal locations, allowing well resolved measurements of the global structure. The comparison also highlights the need to include kinetic effects in the MHD model once beta exceeds 80% of the kink mode limit without a conducting wall. Two distinct types of response fields are identified by the linear ideal MHD model: one that consists of localized currents at the rational surfaces that cancel the applied resonant field and another that is excited by the components of the external field that couple to the kink mode. Numerical simulations show these two fields have similar amplitudes in ITER-shaped DIII-D discharges where n = 3 fields are used to suppress edge localized modes.
|
|
| 9. |
- Okabayashi, M., et al.
(författare)
-
Control of the resistive wall mode with internal coils in the DIII-D tokamak
- 2005
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 45:12, s. 1715-1731
-
Tidskriftsartikel (refereegranskat)abstract
- Internal coils, 'I-Coils', were installed inside the vacuum vessel of the DIII-D device to generate non-axisymmetric magnetic fields to act directly on the plasma. These fields are predicted to stabilize the resistive wall mode (RWM) branch of the long-wavelength external kink mode with plasma beta close to the ideal wall limit. Feedback using these I-Coils was found to be more effective as compared to using external coils located outside the vacuum vessel. Locating the coils inside the vessel allows for a faster response and the coil geometry also allows for better coupling to the helical mode structure. Initial results were reported previously (Strait E.J. et al 2004 Phys. Plasmas 11 2505). This paper reports on results from extended feedback stabilization operations, achieving plasma parameters up to the regime of Cβ ≈ 1.0 and open loop growth rates of γopenτw ≳ 25 where the RWM was predicted to be unstable with only the 'rotational viscous stabilization mechanism'. Here Cβ ≈ (β - βno-wall.limit)/(βideal.wall.limit - βno-wall.limit) is a measure of the beta relative to the stability limits without a wall and with a perfectly conducting wall, and τw is the resistive flux penetration time of the wall. These feedback experimental results clarified the processes of dynamic error field correction and direct RWM stabilization, both of which took place simultaneously during RWM feedback stabilization operation. MARS-F modelling provides a critical rotation velocity in reasonable agreement with the experiment and predicts that the growth rate increases rapidly as rotation decreases below the critical. The MARS-F code also predicted that for successful RWM magnetic feedback, the characteristic time of the power supply should be limited to a fraction of the growth time of the targeted RWM. The possibility of further improvements in the presently achievable range of operation of feedback gain values is also discussed.
|
|
| 10. |
- Petri, M., et al.
(författare)
-
Structure of C-16: Testing shell model and ab initio approaches
- 2012
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:4, s. Art. no. 044329-
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states in C-16 were populated via the Be-9(N-17,C-16+gamma)X one-proton knockout reaction. The lifetime of the 2(1)(+) state in C-16 was measured using the recoil distance method. The extracted lifetime of tau(+)(21) = 11.4(-0.9)(+0.8)(stat) +/- 0.7(syst(B rho))(-1.5)(+0.0)(syst(feeding)) ps yields a deduced B(E2;2(1)(+) -> 0(1)(+)) = 4.21(-0.26)(+0.34)(stat)(-0.24)(+0.28)(syst(B rho))(-0.00)(+0.64)(syst(feeding)) e(2)fm(4) value in good agreement with a previous measurement. The one-proton knockout cross section is used to extract the proton amplitude of the C-16 2(1)(+) state, which confirms the neutron dominant character of this state. Gamma-ray branching ratios between the 2(2)(+) state and the 2(1)(+) and ground states were also determined. The results are compared with p-sd shell model and no-core shell model (with NN and NN + NNN) calculations. The inclusion of three-body forces are essential in order for the no-core shell model calculations to reproduce the experimental findings on the gamma-ray branching ratios.
|
|
| 11. |
- Hyldegaard, S., et al.
(författare)
-
Precise branching ratios to unbound 12C states from 12N and 12B [beta]-decays
- 2009
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 678:5, s. 459 - 464
-
Tidskriftsartikel (refereegranskat)abstract
- Two complementary experimental techniques have been used to extract precise branching ratios to unbound states in 12C from 12N and 12B [beta]-decays. In the first the three [alpha]-particles emitted after [beta]-decay are measured in coincidence in separate detectors, while in the second method 12N and 12B are implanted in a detector and the summed energy of the three [alpha]-particles is measured directly. For the narrow states at 7.654 MeV (0+) and 12.71 MeV (1+) the resulting branching ratios are both smaller than previous measurements by a factor of [similar, equals]2. The experimental results are compared to no-core shell model calculations with realistic interactions from chiral perturbation theory, and inclusion of three-nucleon forces is found to give improved agreement.
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
- Chu, M.S., et al.
(författare)
-
Physics of Plasmas Modeling of Feedback and Rotation Stabilization of the Resistive Wall Mode in Tokamaks
- 2004
-
Ingår i: Physics of Plasmas. ; 11, s. 2497-
-
Tidskriftsartikel (refereegranskat)abstract
- Steady-state operation of the advanced tokamak reactor relies on maintaining plasma stability with respect to the resistive wall mode ~RWM!. Active magnetic feedback and plasma rotation are the two methods proposed and demonstrated for this purpose. A comprehensive modeling effort including both magnetic feedback and plasma rotation is needed for understanding the physical mechanisms of the stabilization and to project to future devices. For plasma with low rotation, a complete solution for the feedback issue is obtained by assuming the plasma obeys ideal magnetohydrodynamics ~MHDs! and utilizing a normal mode approach ~NMA! @M. S. Chu et al., Nucl. Fusion 43, 441 ~2003!#. It is found that poloidal sensors are more effective than radial sensors and coils inside of the vacuum vessel more effective than outside. For plasmas with non-negligible rotation, a comprehensive linear nonideal MHD code, the MARS-F has been found to be suitable. MARS-F @Y. Q. Liu et al., Phys. Plasmas 7, 3681 ~2000!# has been benchmarked in the ideal MHD limit against the NMA. The effect of rotation stabilization of the plasma depends on the plasma dissipation model. Broad qualitative features of the experiment are reproduced. Rotation reduces the feedback gain required for RWM stabilization. Reduction is significant when rotation is near the critical rotation speed needed for stabilization. The International Thermonuclear Experimental Reactor ~ITER! @R. Aymar et al., Plasma Phys. Controlled Fusion 44, 519 ~2002!# ~scenario IV for advanced tokamak operation! may be feedback stabilized with babove the no wall limit and up to an increment of ;50% towards the ideal limit. Rotation further improves the stability.
|
|
| 15. |
|
|
| 16. |
- La Haye, R.J., et al.
(författare)
-
Scaling of the Plasma Rotation Needed for Stabilizing the n = 1 Resistive Wall Mode (Ideal Kink) in the DIII D Tokamak
- 2004
-
Ingår i: Nuclear Fusion. - 1741-4326 .- 0029-5515. ; 44, s. 1197-
-
Tidskriftsartikel (refereegranskat)abstract
- Experiments in the DIII-D tokamak show that the n = 1 ideal kink can be stabilized by a resistive wall if the plasma is rotating fast enough. A database of the onset of the n = 1 resistive wall mode as a function of the equilibrium toroidal magnetic field, the plasma density and the toroidal rotation has been assembled for plasmas with beta between the theoretically predicted no wall and ideal wall stability limits. The critical rotation frequency is found to scale as the inverse of the Alfvén time with ? ?A 0.02 (evaluated at the q = 2 surface at ? 0.6) or ? ?S 0.7, where ?S is the sound time. The dependence of ? ? A or ? ?S on ?N/?N,no wall from 1?2 is weak and suggests the plasmas are in the 'intermediate dissipation' regime.
|
|
| 17. |
- Dagsson-Waldhauserova, P., et al.
(författare)
-
Physical properties of suspended dust during moist and low wind conditions in Iceland
- 2014
-
Ingår i: Icelandic Agricultural Sciences. - 1670-567X. ; 27, s. 25-39
-
Tidskriftsartikel (refereegranskat)abstract
- We measured a dust event which occurred during wet and low wind/windless conditions as the result of surface heating in August 2013. Maximum particle number concentration (PM similar to 0.3-10 mu m) reached 149,954 particles cm(-3) min(-1) while mass concentration (PM<10 m) was 1757 g m-3 min-1. The suspended dust was very fine with the highest number of particles in the size range 0.3-0.337 mu m, followed by particles 1.5-5 mu m in diameter. Close-to-ultrafine particle size distributions showed a significant increase in number with the severity of the measured dust event (during dust peaks). Number concentrations were well correlated with mass concentrations. The mineralogy and geochemical compositions showed that glaciogenic dust contains sharp-tipped shards with bubbles and 80 % of the particulate matter is volcanic glass rich in heavy metals. Wet dust particles were mobilized within < 4 hours. This is the first scientific study of particle size distributions in an Icelandic dust event including findings on initiation of dust suspension.
|
|
| 18. |
|
|
| 19. |
- Orce, J. N., et al.
(författare)
-
Reorientation-effect measurement of the (2+ 1 Eˆ22+ 1) matrix element in 10Be
- 2012
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:4
-
Tidskriftsartikel (refereegranskat)abstract
- The highly-efficient and segmented TIGRESS gamma-ray spectrometer at TRIUMF has been used to perform a reorientation-effect Coulomb-excitation study of the 2(1)(+) state at 3.368 MeV in Be-10. This is the first Coulomb-excitation measurement that enables one to obtain information on diagonal matrix elements for such a high-lying first excited state from gamma-ray data. With the availability of accurate lifetime data, a value of -0.110 +/- 0.087 eb is determined for the diagonal matrix element, which assuming the rotor model, leads to a negative spectroscopic quadrupole moment of Q(S)(2(1)(+)) = -0.083 +/- 0.066 eb. This result is in agreement with both no-core shell-model calculations performed in this work with the CD-Bonn 2000 two-nucleon potential and large shell-model spaces, and Green's function Monte Carlo predictions with two-plus three-nucleon potentials.
|
|
| 20. |
- Šaroun, J., et al.
(författare)
-
Neutron optics concept for the materials engineering diffractometer at the ESS
- 2016
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 746:1
-
Tidskriftsartikel (refereegranskat)abstract
- The Beamline for European Materials Engineering Research (BEER) has been recently proposed to be built at the European Spallation Source (ESS). The presented concept of neutron delivery optics for this instrument addresses the problems of bi-spectral beam extraction from a small moderator, optimization of neutron guides profile for long-range neutron transport and focusing at the sample under various constraints. They include free space before and after the guides, a narrow guide section with gaps for choppers, closing of direct line of sight and cost reduction by optimization of the guides cross-section and coating. A system of slits and exchangeable focusing optics is proposed in order to match various wavelength resolution options provided by the pulse shaping and modulation choppers, which permits to efficiently trade resolution for intensity in a wide range. Simulated performance characteristics such as brilliance transfer ratio are complemented by the analysis of the histories of "useful" neutrons obtained by back tracing neutrons hitting the sample, which helps to optimize some of the neutron guide parameters such as supermirror coating.
|
|
| 21. |
- Voss, P., et al.
(författare)
-
Excited-state transition-rate measurements in C-18
- 2012
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:1
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states in C-18 were populated by the one-proton knockout reaction of an intermediate energy radioactive N-19 beam. The lifetime of the first 2(+) state was measured with the Koln/NSCL plunger via the recoil distance method to be tau (2(1)(+)) = 22.4 +/- 0.9(stat)(-2.2)(+3.3)(syst) ps, which corresponds to a reduced quadrupole transition strength of B(E2; 2(1)(+) -> 0(1)(+)) = 3.64(-0.14)(+ 0.15)(stat)(-0.47)(+0.40)(syst) e(2)fm(4). In addition, an upper limit on the lifetime of a higher-lying state feeding the 2(1)(+) state was measured to be tau
|
|
| 22. |
|
|
| 23. |
- Ekstrom, A., et al.
(författare)
-
Accurate nuclear radii and binding energies from a chiral interaction
- 2015
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 91:5
-
Tidskriftsartikel (refereegranskat)abstract
- With the goal of developing predictive ab initio capability for light and medium-mass nuclei, two-nucleon and three-nucleon forces from chiral effective field theory are optimized simultaneously to low-energy nucleon-nucleon scattering data, as well as binding energies and radii of few-nucleon systems and selected isotopes of carbon and oxygen. Coupled-cluster calculations based on this interaction, named NNLOsat, yield accurate binding energies and radii of nuclei up to Ca-40, and are consistent with the empirical saturation point of symmetric nuclear matter. In addition, the low-lying collective J(pi) = 3(-) states in O-16 and 40Ca are described accurately, while spectra for selected p- and sd-shell nuclei are in reasonable agreement with experiment.
|
|
| 24. |
- Karabin, Marcin, et al.
(författare)
-
3D Cadastre in the Case of Engineering Objects, such as Bridges and Road Viaducts
- 2021
-
Ingår i: Proceedings 7th International FIG Workshop on 3D Cadastres. - Copenhagen, Denmark : International Federation of Surveyors (FIG). ; , s. 19-36
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- At present, the implementation of cadastral registration of transport investments (such as railway lines on bridges and on viaducts, roads on viaducts, etc.) is performed in the so-called "layer" system. This means that many objects are constructed at different levels (layers) within the space of a given parcel. Several parties may be interested in developing certain fragments of the parcel space; each of them is interested in acquiring rights only to a specified part of the parcel (its specified layer), in which given investment is implemented by that party. The legal conditions binding in many countries do not allow for implementation of such type investments within the space of a someone else's cadastral parcels, based on the ownership right. This is due to the fact, in accordance with the "superficies solo cedit" rule applicable in many EU countries, the ownership right extends above and below the parcel space and cadastral systems do not allow for vertical division of a real property. The conventional 2D cadastre, which does not allow vertical division of the parcel space, forces an investor to buy a whole parcel or to get other rights which allows using a specified space of someone else's parcel, such as easiment rights. Buying of an entire parcel in which space bridges and road viaducts investments will be performed and not being able to divide the land space vertically makes it practically impossible to sell the parcel under a viaduct because following the rule above the viaduct is part of the land parcel. Therefore, the space is not optimally utilised. The easement right has some disadvantages, as it cannot be encumbered with a mortgage; therefore it is not the basis of crediting a given investment. The 3D cadastre allows delineating 3D parcels (from the space of existing 2D parcels) that cover specified fragments of the space and to relate ownership rights to those delineated fragments. Within a 3D cadastre system, such objects can be registered as separate cadastral objects. This allows for the implementation of a line investment in the above-ground space in a flexible way, i.e. it is possible to get financing of an investment based on the mortgage charge of a 3D property and market transactions of the remaining space after delineation of the 3D parcel, covering the bridge or viaduct. This paper focuses on approaches to registration of real property rights in the case of engineering objects, such as bridges and road viaducts, in different EU countries: Austria, Bulgaria, Czech Republic, Croatia, Greece, Poland, Slovenia and Sweden.The authors review the current solutions for the registration of engineering objects in the cadastre, including its effectiveness in ensuring appropriate property rights to construct and exploit such objects, and make a comparison between the countries.
|
|
| 25. |
- Karabin, Marcin, et al.
(författare)
-
Layer approach to ownership in 3D cadastre : a subway case
- 2018
-
Ingår i: 6th International FIG 3D Cadastre Workshop. - Copenhagen : The International Federation of Surveyors, FIG. - 9788792853806 - 9788792853813 ; , s. 111-136
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The paper focuses onapproaches to the registration of real property rights in the case of underground or subway tunnels in different EU countries: Austria, Bulgaria, Czech Republic, Croatia, Greece, Poland, Slovenia, and Sweden. The Authors made analysis of the current way of registration of rights to subway tunnels in the chosen countries, including its effectiveness in ensuring appropriate property rights to construct and exploit tunnels. A special attention was given to limitations related to the lack of the possibility to vertically divide the space, i.e. to divide the space into layers, and to refer the ownership right to the layers. Benefits which might be achieved by the introduction of a 3D real property cadastre were pointed out. The analysis of available data concerning the geometry of subway tunnels in particular countries was presented. The authors tried to answer the question whether the accessible data concerning the geometry of subway tunnels allows to generate a 3D geospatial model of a constructed object, and to specify the space which should be determined as a 3D parcel in the 3D real property cadastre, for the purpose of registering property rights for the object (the tunnel).
|
|
