| 1. |
- Murari, A., et al.
(författare)
-
A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
-
Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
-
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.
|
|
| 2. |
- Joffrin, E., et al.
(författare)
-
Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
-
Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Asztalos, S J, et al.
(författare)
-
Spin yields of neutron-rich nuclei from deep inelastic reactions
- 1999
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 60:4
-
Tidskriftsartikel (refereegranskat)abstract
- The potential for using deep inelastic reactions to populate high-spin states in neutron-rich nuclei is studied in a series of experiments using GAMMASPHERE for gamma-ray detection and a silicon strip detector for measuring the angles of projectilelike and targetlike fragments. In three experiments 61 new transitions up to a maximum spin of 22 (h) over bar in 12 neutron-rich rare-earth nuclei were found. We observe that gamma-ray yields as a function of spin are flatter for all neutron transfer products than for inelastic excitation of either the projectile or target nucleus. Calculations are presented which indicate that this difference cannot be accounted for by quasielastic processes, but more likely are the result of larger energy loss processes, such as deep inelastic reactions. [S0556-2813(99)06009-4].
|
|
| 7. |
- Clark, R M, et al.
(författare)
-
Superdeformation in bismuth
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:1, s. 117-123
-
Tidskriftsartikel (refereegranskat)abstract
- High angular momentum states in Bi-195-197 are populated in two reactions: W-183(F-19,xn)Bi-202-x and Ta-181(Ne-20,xn)Bi-201-x at beam energies of 108 and 123 MeV, respectively. Gamma rays were detected using the Gammasphere array. Three weakly populated rotational sequences have been found. They each have properties characteristic of other superdeformed bands in this mass region. On the basis of cross-bombardment information we believe that one band belongs to each of Bi-195, Bi-196, and Bi-197. The properties of the bands in the odd-Bi nuclei are best reproduced if the odd proton occupies the favored signature of the [651]1/2 orbital, while the band in Bi-196 has this same proton configuration coupled to an additional N=7 (j(15/2)) neutron. The relative behavior of the J((2)) moments of inertia can be qualitatively understood in terms of Pauli-blocking effects.
|
|
| 8. |
- Joss, D T, et al.
(författare)
-
Lifetime measurements of a triaxial band in Ce-133
- 1998
-
Ingår i: Acta Physica Hungarica A. - 1219-7580 .- 1588-2675. ; 7:1, s. 111-112
-
Tidskriftsartikel (refereegranskat)abstract
- The Doppler shift attenuation method has been used to determine the transition quadrupole moment of a triaxial band belonging to the gamma-soft nucleus, Ce-133. Doppler broadened lineshape (DBLS) analysis has revealed the magnitude of the Q(t) value to be similar to 2.4 eb. This contribution provides new information of (i) the transition quadrupole moment of this band (ii) the lifetimes of in-band and sidefeeding transitions and (iii) the relative deformations of coexisting nuclear shapes.
|
|
| 9. |
- Joss, D T, et al.
(författare)
-
Lifetime measurements of a triaxial band in Ce-133
- 1998
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 58:6, s. 3219-3222
-
Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of states within a triaxial band belonging to;the gamma-soft nucleus Ce-133 have been determined through a Doppler-broadened line shape analysis. A value, Q(t)approximate to 2.2 eb, has been found for the transition quadrupole moment which is considerably smaller than that of superdeformed structures (Q(t)approximate to 7.4 e b) in this mass region. The results are discussed in terms of deformation self-consistent calculations based on the total Routhian surface formalism. [S0556-2813(98)01912-8].
|
|
| 10. |
- McNabb, D P, et al.
(författare)
-
Superdeformation in Po-198
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:2, s. R541-R543
-
Tidskriftsartikel (refereegranskat)abstract
- The Yb-174(Si-29,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in Po-198. Resulting gamma rays were observed with Gammasphere. A weakly populated superdeformed band of 10 gamma-ray transitions was found and has been assigned to Po-198. This is the first observation of an SD band in the A approximate to 190 region in a nucleus with Z > 83. The J((2))) of the new band is very similar to those of the yrast SD bands in Hg-194 and Pb-196. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.
|
|
| 11. |
- Asztalos, S. J., et al.
(författare)
-
Isotopic yields of neutron-rich nuclei from deep-inelastic reactions
- 2000
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 6101:1
-
Tidskriftsartikel (refereegranskat)abstract
- We follow up on our earlier work involving a light projectile (Ca-48) to populate high spin states in neutron-rich nuclei with results from experiments involving a heavier projectile (Sm-154) fur the purposes of studying isotopic yields. These yields, which in some cases were mensurable down to a level of 0.1 of the total reaction cross section, are presented from three separate reactions. A trend in the isotopic yields towards N/Z equilibration is observed in one experiment having a large disparity in N/Z ratios between the projectile and target. In the two other reactions, where the N/Z driving force is less pronounced, the yields are instead clustered around the projectile and target nuclei. We present correlated projectilelike and targetlike fragment isotopic yields derived from gamma-gamma coincidences, a technique that enables one to partition the yield of an isotope according to the amount of neutron evaporation. Using this method we find that for the zero-neutron evaporation channel transfer occurs predominantly into the light fragment, consistent with the nature of the deep-inelastic mechanism. We further find that multiple-neutron evaporation contributes substantially to the yields of the isotopes.
|
|
| 12. |
- Lee, I Y, et al.
(författare)
-
Study of neutron-rich nuclei using deep-inelastic reactions
- 1997
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 56:2, s. 753-759
-
Tidskriftsartikel (refereegranskat)abstract
- We have used the Ca-48+Yb-176 reaction to study the population of high-spin states in neutron-rich nuclei by deep-inelastic reactions. Using Gammasphere, we observed gamma transitions from nuclei several neutrons richer than the target. Yrast states with spin up to 20 were populated in this reaction. High-spin states in Yb-175,Yb-177,Yb-178 were observed. In this region of reduced pairing, a reference based on experimental data was used to derive experimental Routhians. Systematics of experimental Routhians in neutron-rich Yb nuclei compare well with cranked shell-model calculations.
|
|
| 13. |
- Clark, R M, et al.
(författare)
-
Relative deformations of superdeformed bands in Ce-131,Ce-132
- 1996
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 76:19, s. 3510-3513
-
Tidskriftsartikel (refereegranskat)abstract
- The quadrupole moments Q(0) of five superdeformed bands in Ce-131,Ce-132 have been established using the Doppler-shift attenuation method; for the first time, we can compare relative deformations of yrast and excited bands in different nuclei to an accuracy of similar or equal to(5-7)%. Four of the five bands have very similar deformations, while the excited band in Ce-131 has a somewhat larger quadrupole moment. Important new information is presented on the shape-driving force of the vi(13/2) orbital, the stability of the second minimum with respect to particle excitations, the relative deformations of identical bands, the nature of the sidefeeding, and the time scale of the decay process.
|
|
| 14. |
- CLARK, RM, et al.
(författare)
-
SUPERDEFORMATION IN THE BISMUTH NUCLEI
- 1995
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 51:3, s. R1052-R1056
-
Tidskriftsartikel (refereegranskat)
|
|
| 15. |
- Klamra, Wlodzimierz, et al.
(författare)
-
High-spin multiparticle-hole excitations in Eu-148
- 2001
-
Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 10:1, s. 11-12
-
Tidskriftsartikel (refereegranskat)abstract
- Studies by means of 155 MeV Al-27 bombardment on a Te-130 target revealed in Eu-148 high-spin structures up to spin 31 (n) over tilde, in addition to a cascade extended to the 11088.1 keV excitation. The observed levels are tentatively assigned as complex multiparticle-hole proton and neutron configurations.
|
|
| 16. |
- LaFosse, D R, et al.
(författare)
-
Search for hyperdeformation in Gd-146,Gd-147
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 54:4, s. 1585-1588
-
Tidskriftsartikel (refereegranskat)abstract
- A search was undertaken to look for evidence of hyperdeformation in Gd-146,Gd-147. Three experiments employing Gammasphere for gamma-ray detection coupled with the Microball for channel selection via charged particle detection were carried out with increasing detection sensitivity and statistics. No definitive evidence for band structures that could be assigned to hyperdeformation could be found. Candidates previously reported are shown not to have properties consistent with a band structure.
|
|
| 17. |
- Olsson, NC, et al.
(författare)
-
Social skills group training in high-functioning autism: A qualitative responder study
- 2016
-
Ingår i: Autism : the international journal of research and practice. - : SAGE Publications. - 1461-7005. ; 20:8, s. 995-1010
-
Tidskriftsartikel (refereegranskat)abstract
- Systematic reviews show some evidence for the efficacy of group-based social skills group training in children and adolescents with autism spectrum disorder, but more rigorous research is needed to endorse generalizability. In addition, little is known about the perspectives of autistic individuals participating in social skills group training. Using a qualitative approach, the objective of this study was to examine experiences and opinions about social skills group training of children and adolescents with higher functioning autism spectrum disorder and their parents following participation in a manualized social skills group training (“KONTAKT”). Within an ongoing randomized controlled clinical trial (NCT01854346) and based on outcome data from the Social Responsiveness Scale, six high responders and five low-to-non-responders to social skills group training and one parent of each child (N = 22) were deep interviewed. Interestingly, both high responders and low-to-non-responders (and their parents) reported improvements in social communication and related skills (e.g. awareness of own difficulties, self-confidence, independence in everyday life) and overall treatment satisfaction, although more positive intervention experiences were expressed by responders. These findings highlight the added value of collecting verbal data in addition to quantitative data in a comprehensive evaluation of social skills group training.
|
|
| 18. |
- Senfter, S., et al.
(författare)
-
Flood forecasting for the river inn
- 2009
-
Ingår i: Sustainable Natural Hazard Management in Alpine Environments. - Berlin : Springer Berlin/Heidelberg. - 9783642032288 ; , s. 35-67
-
Bokkapitel (refereegranskat)abstract
- The river Inn as the main river in Tyrol moulds the settlement and economic area in Northern Tyrol in a considerable way. 66 % of the area drains into the Inn, whereas the remaining 34% drain into the Lech, the Grossache and the Drau in East Tyrol. The Inn flows through Tyrol for about 200∈km, from the Swiss border at Martinsbruck to Kufstein, where it leaves Tyrol and flows into Bavaria/Germany (Fig. 2.1).
|
|
