| 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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| 6. |
- Menkveld, Albert J., et al.
(författare)
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Nonstandard Errors
- 2024
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Ingår i: JOURNAL OF FINANCE. - : Wiley-Blackwell. - 0022-1082 .- 1540-6261. ; 79:3, s. 2339-2390
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Tidskriftsartikel (refereegranskat)abstract
- In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty-nonstandard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for more reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants.
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| 7. |
- Esposito, B., et al.
(författare)
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Progress of Design and Development for the ITER Radial Neutron Camera
- 2022
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Ingår i: Journal of fusion energy. - : Springer. - 0164-0313 .- 1572-9591. ; 41:2
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents an overview of the design status of the Radial Neutron Camera (RNC), that, together with the Vertical Neutron Camera, will provide, through reconstruction techniques applied to the measured line-integrated neutron fluxes, the time resolved measurement of the ITER neutron and alpha-source profile (i.e. neutron emissivity, neutrons emitted per unit time and volume). The RNC is composed of two subsystems, the In-Port RNC and Ex-Port RNC located, respectively, inside and outside the Plug of Equatorial Port #01. The In-Port subsystem is in a more advanced design stage since it has recently undergone the Final Design Review in the ITER procurement process. The paper describes the diagnostic layout, the interfaces, the measurement capabilities and the main challenges in its realization. Prototyping and testing of neutron detectors and electronics components were carried out and led to the choice of the component solutions that can match the environmental and operational constraints in terms radiation hardness, high temperature and electromagnetic compatibility. The performance of the RNC in terms of neutron emissivity measurement capability was assessed through 1D and 2D reconstruction analysis. It is proven that the neutron emissivity can be reconstructed in real-time within the measurement requirements: 10% accuracy, 10 ms time resolution and a/10 (a = plasma minor radius) space resolution.
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| 9. |
- Tardocchi, M., et al.
(författare)
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High rate neutron and gamma ray spectroscopy of magnetic confinement fusion plasmas
- 2020
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Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- An important instrumental development work has been done in the last two decades in the field of neutron and gamma ray spectroscopic measurements of magnetic confinement plasmas. Starting from the present state of the art instrumentation installed at JET, this paper reviews the recent development that has been carried out within the EUROFUSION programme for the forthcoming high power JET D and DT campaign. This development was dedicated to the realization of new compact neutron and gamma-ray spectrometers which combine very high energy resolution (typically better than 5%) and MHz counting rate capabilities allowing for time resolution in the 10 ms time scale. One of the advantages offered by the compact dimensions of these spectrometers is to make possible their use in multiple sight-line camera configurations, such as for future burning plasma reactors (ITER and DEMO). New compact neutron spectrometers based on single crystal diamond detectors have been developed and installed at JET for measurements of the 14MeV neutron spectrum. Measurements on a portable DT neutron generator have shown that neutron spectroscopy of the accelerated beam ions at unprecedented energy resolution (similar to 1% at 14 MeV) is possible, which opens up new opportunities for diagnosing DT plasmas. For what concerns gamma ray measurements, the JET gamma ray camera has been recently upgraded with new compact spectrometers based on a LaBr3 scintillator coupled to Silicon Photomultiplier with the dual aim to improve the spectroscopic and rate capabilities of the detectors. The upgrade camera system will reconstruct the spatial gamma ray emissivity from the plasma in the MeV energy range at MHz counting rates and energy resolution in the 2-4% range. This will allow physics studies of gamma rays produced by the interaction of fast ions with impurities in the plasma and bremsstrahlung emission from runaway electrons.
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| 10. |
- Anwar, S., et al.
(författare)
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Unequal Jury Representation and Its Consequences
- 2022
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Ingår i: American Economic Review-Insights. - : American Economic Association. - 2640-205X .- 2640-2068. ; 4:2, s. 159-174
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the extent and consequences of unequal representation on juries in Harris County, Texas. We first document that residents from predominantly White and high-income neighborhoods are substantially overrepresented on juries. Using quasirandom variation in those called for jury duty each day, we next establish that Black defendants are more likely to be convicted and receive longer sentences from juries with more residents from these overrepresented neighborhoods. We estimate that equal representation would reduce Black defendants' median sentence length by 50 percent and the probability of receiving a life sentence by 67 percent. Straightforward remedies could mitigate these legally unwarranted racial disparities.
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| 12. |
- Eriksson, Benjamin, et al.
(författare)
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Determining the fuel ion ratio for D(T)and T(D) plasmas at JET using neutron time-of-flight spectrometry
- 2022
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Ingår i: Plasma Physics and Controlled Fusion. - : Institute of Physics (IOP). - 0741-3335 .- 1361-6587. ; 64
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Tidskriftsartikel (refereegranskat)abstract
- The fusion fuel ion ratio, nΤ/nD, is an important plasma parameter that needs to be tuned to maximize the power of a tokamak type fusion reactor. It is recognized as a parameter required for optimizing several ITER operating scenarios, and will likely be continuously monitored in future high-performance fusion devices such as DEMO. Tritium was recently introduced in the Joint European Torus (JET) plasma for the first time since the 1997 DTE1 and 2003 TTE campaigns, enabling the possibility to investigate fuel ion ratios. We present a method for measuring nΤ/nD using neutron time-of-flight (TOF) spectrometry. By fitting the measured neutron spectral features, the relative reaction rate intensities between different ion species can be inferred, from which the fuel ion ratio can be extracted for a corresponding modeled reactivity. Unlike previous measurements of nT/nD using neutron spectrometry, we utilize the neutron energy continuum produced in the three-body TT reaction to determine the fuel ion ratio for plasmas with large concentrations of tritium. Furthermore, the use of neutron TOF spectrometry has never previously been demonstrated for evaluating nT/nD. The method is applied to TOF spectra acquired with TOFOR (JET name KM11) and shown to be consistent with the optical JET diagnostic KT5P which uses optical spectroscopy of a modified Penning gauge plasma to measure tritium and deuterium concentrations in the divertor exhaust gas.
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| 13. |
- Hellkvist, L., et al.
(författare)
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High dose pollen intralymphatic immunotherapy: Two RDBPC trials question the benefit of dose increase
- 2022
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Ingår i: Allergy. - : Wiley. - 0105-4538 .- 1398-9995. ; 77:3, s. 883-96
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Tidskriftsartikel (refereegranskat)abstract
- Background The same dosing schedule, 1000 SQ-U times three, with one-month intervals, have been evaluated in most trials of intralymphatic immunotherapy (ILIT) for the treatment of allergic rhinitis (AR). The present studies evaluated if a dose escalation in ILIT can enhance the clinical and immunological effects, without compromising safety. Methods Two randomized double-blind placebo-controlled trials of ILIT for grass pollen-induced AR were performed. The first included 29 patients that had recently ended 3 years of SCIT and the second contained 39 not previously vaccinated patients. An up-dosage of 1000-3000-10,000 (5000 + 5000 with 30 minutes apart) SQ-U with 1 month in between was evaluated. Results Doses up to 10,000 SQ-U were safe after recent SCIT. The combined symptom-medication scores (CSMS) were reduced by 31% and the grass-specific IgG4 levels in blood were doubled. In ILIT de novo, the two first patients that received active treatment developed serious adverse reactions at 5000 SQ-U. A modified up-dosing schedule; 1000-3000-3000 SQ-U appeared to be safe but failed to improve the CSMS. Flow cytometry analyses showed increased activation of lymph node-derived dendritic but not T cells. Quality of life and nasal provocation response did not improve in any study. Conclusion Intralymphatic immunotherapy in high doses after SCIT appears to further reduce grass pollen-induced seasonal symptoms and may be considered as an add-on treatment for patients that do not reach full symptom control after SCIT. Up-dosing schedules de novo with three monthly injections that exceeds 3000 SQ-U should be avoided.
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| 14. |
- Hjalmarsson, E, et al.
(författare)
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A 5-Year Open-Label Follow-up of a Randomized Double-Blind Placebo-Controlled Trial of Intralymphatic Immunotherapy for Birch and Grass Allergy Reveals Long-term Beneficial Effects
- 2023
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Ingår i: Journal of investigational allergology & clinical immunology. - : Esmon Publicidad, SA. - 1018-9068. ; 33:5, s. 362-372
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Tidskriftsartikel (refereegranskat)abstract
- Background: Intralymphatic immunotherapy (ILIT) has been proposed as a novel, less time-consuming alternative to conventional allergy immunotherapy (AIT). Few previous studies have evaluated its long-term effects. The objective of the study was to complete a 5-year follow-up of a previously performed randomized, double-blind placebo-controlled trial of ILIT for a combination of birch and grass allergens. Methods: Fifty-eight patients with allergic rhinitis were treated with either placebo or a combination of ALK Alutard Birch and Grass 1000 SQ-U, three intralymphatic injections with one-month intervals. A year after the vaccination, symptoms induced by nasal provocation were significantly reduced. 5-6 years later, 20 out of 26 actively treated patients were followed up with a nasal provocation test (NPT), seasonal registration of the combined symptoms and medications score (CSMS), IgE and IgG4 levels in the blood and immunological markers in blood and lymph nodes and compared with 13 unvaccinated controls Results: The ILIT induced reduction in the NPT response seen in year one could not be convincingly reproduced in year five. The new CSMS scores were markedly lower among the previously treated patients than for the control group. Further, grass-specific IgG4 was increased, grass-specific IgE decreased, FcεR1 on basophils reduced, and the amount of memory T-cells in the lymph nodes increased. Conclusion: The combination of seasonal derived clinical data and immunological parameters supports the notion of a long-lasting effect of ILIT. These data support the concept of ILIT as a good alternative to traditional AIT in pollen-induced allergic rhinitis.
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| 15. |
- Hjalmarsson, E, et al.
(författare)
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A five-year open follow up of a randomized, double-blind placebo-controlled trial of intralymphatic immunotherapy for birch and grass reveals remaining beneficial effects
- 2022
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Ingår i: Journal of investigational allergology & clinical immunology. - : Esmon Publicidad, SA. - 1018-9068. ; , s. 0-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Intralymphatic immunotherapy (ILIT) has been proposed as a novel, less time-consuming alternative to conventional allergy immunotherapy (AIT). Few previous studies have evaluated its long-term effects. The objective of the study was to complete a 5-year follow-up of a previously performed randomized, double-blind placebo-controlled trial of ILIT for a combination of birch and grass allergens. Methods: Fifty-eight patients with allergic rhinitis were treated with either placebo or a combination of ALK Alutard Birch and Grass 1000 SQ-U, three intralymphatic injections with one-month intervals. A year after the vaccination, symptoms induced by nasal provocation were significantly reduced. 5-6 years later, 20 out of 26 actively treated patients were followed up with a nasal provocation test (NPT), seasonal registration of the combined symptoms and medications score (CSMS), IgE and IgG4 levels in the blood and immunological markers in blood and lymph nodes and compared with 13 unvaccinated controls Results: The ILIT induced reduction in the NPT response seen in year one could not be convincingly reproduced in year five. The new CSMS scores were markedly lower among the previously treated patients than for the control group. Further, grass-specific IgG4 was increased, grass-specific IgE decreased, FcεR1 on basophils reduced, and the amount of memory T-cells in the lymph nodes increased. Conclusion: The combination of seasonal derived clinical data and immunological parameters supports the notion of a long-lasting effect of ILIT. These data support the concept of ILIT as a good alternative to traditional AIT in pollen-induced allergic rhinitis.
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| 16. |
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| 17. |
- Sandqvist, Aage, et al.
(författare)
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Herschel and Odin observations of H 2 O, CO, CH, CH + , and [N» II] in the barred spiral galaxy NGC 1365: Bar-induced activity in the outer and inner circumnuclear tori
- 2021
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 647
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Tidskriftsartikel (refereegranskat)abstract
- Context. The Odin satellite is now into its twentieth year of operation, much surpassing its design life of two years. One of its major astronomical pursuits was the search for and study of water vapor in diverse regions of the Solar System and the Milky Way galaxy. The Herschel space observatory was needed to detect water vapor in external galaxies. Aims. Our goal is to study the distribution and excitation of water vapor and other molecules in the barred spiral galaxy NGC 1365. Methods. Herschel has observed the central region of NGC 1365 in two positions, and both its SPIRE and PACS observations are available in the Herschel Science Archive. Herschel PACS images have been produced of the 70 and 160 μm infrared emission from the whole galaxy, and also of the cold dust distribution as obtained from the ratio of the 160 to 70 μm images. The Herschel SPIRE observations have been used to produce simultaneously observed maps of the 557 GHz o-H2O, 752 GHz p-H2O, 691 GHz CO(6-5), 1037 GHz CO(9-8), 537 GHz CH, 835 GHz CH+, and the 1461 GHz [N» II] lines (efficiently probing the warm ionized medium) in the inner bar and circumnuclear torus region;-however, these observations have no effective velocity resolution. For this reason Odin has recently observed the 557 GHz ortho-H2O ground state line in the central region with high (5 km s-1) spectral resolution. Results. The emission and absorption of H2O at 557 GHz, with a velocity resolution of 5 km s-1, has been marginally detected in NGC 1365 with Odin. The water vapor is predominantly located in a shocked 15″ (1.3 kpc) region near some central compact radio sources and hot-spot H» II regions, close to the northeast component of the molecular torus surrounding the nucleus. An analysis of the H2O line intensities and velocities indicates that a shock-region is located here. This is corroborated by a statistical image deconvolution of our SEST CO(3-2) observations, yielding 5″ resolution, and a study of our Very Large Array H» I absorption observations, as well as comparisons with published interferometric CO observations. Additionally, an enticing 20″ H» I ridge is found to extend south-southeast from the nucleus, coinciding in position with the southern edge of an O» III outflow cone, emanating from the nucleus. The molecular chemistry of the shocked central region of NGC 1365 is analyzed with special emphasis on the CO, H2O and CH, CH+ results. Conclusions. The dominating activity near the northeast (NE) torus component may have been triggered by the rapid bar-driven inflow into the circumnuclear torus causing cloud-cloud collisions and shocks, leading to the formation of stellar superclusters and, hence, also to more efficient PDR chemistry, which, here, may also benefit from cosmic ray focusing caused by the observed aligned magnetic field. The very high activity near the NE torus component may reflect the fact that the eastern bar-driven gas inflow into the NE region is much more massive than the corresponding western gas inflow into the southwest region. The H2O and CH+ emissions peak in the NE torus region, but the CO and CH emissions are more evenly distributed across the whole circumnuclear torus. The higher energy CO spectral line energy distribution (SLED) is nicely modeled by a low velocity (10 km s-1) shock, which may as well explain the required CH excitation and its high abundance in denser gas. The higher velocity (40 km s-1) shock required to model the H2O SLED in the NE torus region, paired with the intense UV radiation from the observed massive young stellar superclusters, may also explain the high abundance of CH+ in this region. The nuclear H» I ridge may have been created by the action of outflow-driving X-ray photons colliding with ice-covered dust grains. A precessing nuclear engine, as is suggested by the tilted massive inner gas torus, may be necessary to explain the various nuclear outflows encountered.
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