scholarly journals ASCERTAINING THE CORE COLLAPSE SUPERNOVA MECHANISM: The State of the Art and the Road Ahead

2005 ◽  
Vol 55 (1) ◽  
pp. 467-515 ◽  
Author(s):  
Anthony Mezzacappa
Keyword(s):  
State Of The Art ◽  
The State ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Road ◽  
The Core

scholarly journals Thoughts on Core-Collapse Supernova Theory

2007 ◽  
Vol 3 (S250) ◽  
pp. 185-192 ◽  
Author(s):  
Adam Burrows ◽  
Luc Dessart ◽  
Christian D. Ott ◽  
Eli Livne ◽  
Jeremiah Murphy
Keyword(s):  
Spherical Symmetry ◽  
State Of The Art ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Core ◽  
Heating Mechanism ◽  
Numerical Tools ◽  
Computational Resources ◽  
Do So

AbstractAn emerging conclusion of theoretical supernova research is that the breaking of spherical symmetry may be the key to the elusive mechanism of explosion. Such explorations require state-of-the-art multi-dimensional numerical tools and significant computational resources. Despite the thousands of man-years and thousands of CPU-years devoted to date to studying the supernova mystery, both require further evolution. There are many computationally-challenging instabilities in the core, before, during, and after the launch of the shock, and a variety of multi-dimensional mechanisms are now being actively explored. These include the neutrino heating mechanism, the MHD jet mechanism, and an acoustic mechanism. The latter is the most controversial, and, as with all the contenders, requires detailed testing and scrutiny. In this paper, we analyze recent attempts to do so, and suggests methods to improve them.

scholarly journals Towards an understanding of the resolution dependence of Core-Collapse Supernova simulations

2019 ◽  
Vol 490 (4) ◽  
pp. 4622-4637 ◽  
Author(s):  
Hiroki Nagakura ◽  
Adam Burrows ◽  
David Radice ◽  
David Vartanyan
Keyword(s):  
Spatial Resolution ◽  
State Of The Art ◽  
Three Dimensional ◽  
Core Collapse ◽  
Turbulent Stress ◽  
Critical Aspect ◽  
Core Collapse Supernova ◽  
Nuclear Equation Of State ◽  
Turbulent Eddies ◽  
Polar Grid

ABSTRACT Using our new state-of-the-art core-collapse supernova (CCSN) code Fornax, we explore the dependence upon spatial resolution of the outcome and character of three-dimensional (3D) supernova simulations. For the same 19 M⊙ progenitor star, energy and radial binning, neutrino microphysics, and nuclear equation of state, changing only the number of angular bins in the θ and ϕ directions, we witness that our lowest resolution 3D simulation does not explode. However, when jumping progressively up in resolution by factors of two in each angular direction on our spherical-polar grid, models then explode, and explode slightly more vigorously with increasing resolution. This suggests that there can be a qualitative dependence of the outcome of 3D CCSN simulations upon spatial resolution. The critical aspect of higher spatial resolution is the adequate capturing of the physics of neutrino-driven turbulence, in particular its Reynolds stress. The greater numerical viscosity of lower resolution simulations results in greater drag on the turbulent eddies that embody turbulent stress, and, hence, in a diminution of their vigor. Turbulent stress not only pushes the temporarily stalled shock further out, but bootstraps a concomitant increase in the deposited neutrino power. Both effects together lie at the core of the resolution dependence we observe.

Ex-Vessel Coolability Analysis for a Belgian NPP

2009 ◽  
Author(s):  
Jarne R. Verpoorten ◽  
Miche`le Auglaire ◽  
Frank Bertels
Keyword(s):  
State Of The Art ◽  
The State ◽  
Severe Accident ◽  
Research Projects ◽  
Specific Data ◽  
The Core ◽  
Core Damage ◽  
Accident Management ◽  
Lower Head ◽  
Core Cooling

During a hypothetical Severe Accident (SA), core damage is to be expected due to insufficient core cooling. If the lack of core cooling persists, the degradation of the core can continue and could lead to the presence of corium in the lower plenum. There, the thermo-mechanical attack of the lower head by the corium could eventually lead to vessel failure and corium release to the reactor cavity pit. In this paper, it is described how the international state-of-the-art knowledge has been applied in combination with plant-specific data in order to obtain a custom Severe Accident Management (SAM) approach and hardware adaptations for existing NPPs. Also the interest of Tractebel Engineering in future SA research projects related to this topic will be addressed from the viewpoint of keeping the analysis up-to-date with the state-of-the art knowledge.

scholarly journals A Biscriptual Morphological Transducer for Crimean Tatar

2019 ◽  
Author(s):  
Francis M. Tyers ◽  
Jonathan N. Washington ◽  
Darya Kavitskaya ◽  
Memduh Gökırmak
Keyword(s):  
Computational Linguistics ◽  
Morphological Analysis ◽  
State Of The Art ◽  
Full Range ◽  
The State ◽  
Loan Words ◽  
The Core ◽  
Finite State ◽  
Morphological Modelling ◽  
Crimean Tatar

This paper describes a weighted finite-state morphological transducer for Crimean Tatar able to analyse and generate in both Latin and Cyrillic orthographies. This transducer was developed by a team including a community member and language expert, a field linguist who works with the community, a Turkologist with computational linguistics expertise, and an experienced computational linguist with Turkic expertise. Dealing with two orthographic systems in the same transducer is challenging as they employ different strategies to deal with the spelling of loan words and encode the full range of the language's phonemes and their interaction. We develop the core transducer using the Latin orthography and then design a separate transliteration transducer to map the surface forms to Cyrillic. To help control the non-determinism in the orthographic mapping, we use weights to prioritise forms seen in the corpus. We perform an evaluation of all components of the system, finding an accuracy above 90% for morphological analysis and near 90% for orthographic conversion. This comprises the state of the art for Crimean Tatar morphological modelling, and, to our knowledge, is the first biscriptual single morphological transducer for any language.

scholarly journals The core collapse supernova rate from 24 years of data of the Large Volume Detector

2017 ◽  
Vol 888 ◽  
pp. 012256 ◽  
Author(s):  
G. Bruno ◽  
W. Fulgione ◽  
A. Molinario ◽  
C. Vigorito ◽  
Keyword(s):  
Large Volume ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Core ◽  
Large Volume Detector

scholarly journals THE CORE COLLAPSE SUPERNOVA RATE FROM THE SDSS-II SUPERNOVA SURVEY

2014 ◽  
Vol 792 (2) ◽  
pp. 135 ◽  
Author(s):  
Matt Taylor ◽  
David Cinabro ◽  
Ben Dilday ◽  
Lluis Galbany ◽  
Ravi R. Gupta ◽  
...  
Keyword(s):  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Core

scholarly journals Three-dimensional models of core-collapse supernovae from low-mass progenitors with implications for Crab

2020 ◽  
Vol 496 (2) ◽  
pp. 2039-2084 ◽  
Author(s):  
G Stockinger ◽  
H-T Janka ◽  
D Kresse ◽  
T Melson ◽  
T Ertl ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Iron Core ◽  
Core Collapse ◽  
Crab Pulsar ◽  
Core Collapse Supernova ◽  
Spin Period ◽  
The Core ◽  
Low Mass ◽  
Catch Up ◽  
Three Dimensional Models

ABSTRACT We present 3D full-sphere supernova simulations of non-rotating low-mass (∼9 M⊙) progenitors, covering the entire evolution from core collapse through bounce and shock revival, through shock breakout from the stellar surface, until fallback is completed several days later. We obtain low-energy explosions (∼0.5–1.0 × 1050 erg) of iron-core progenitors at the low-mass end of the core-collapse supernova (LMCCSN) domain and compare to a super-AGB (sAGB) progenitor with an oxygen–neon–magnesium core that collapses and explodes as electron-capture supernova (ECSN). The onset of the explosion in the LMCCSN models is modelled self-consistently using the vertex-prometheus code, whereas the ECSN explosion is modelled using parametric neutrino transport in the prometheus-HOTB code, choosing different explosion energies in the range of previous self-consistent models. The sAGB and LMCCSN progenitors that share structural similarities have almost spherical explosions with little metal mixing into the hydrogen envelope. A LMCCSN with less second dredge-up results in a highly asymmetric explosion. It shows efficient mixing and dramatic shock deceleration in the extended hydrogen envelope. Both properties allow fast nickel plumes to catch up with the shock, leading to extreme shock deformation and aspherical shock breakout. Fallback masses of $\mathord {\lesssim }\, 5\, \mathord {\times }\, 10^{-3}$ M⊙ have no significant effects on the neutron star (NS) masses and kicks. The anisotropic fallback carries considerable angular momentum, however, and determines the spin of the newly born NS. The LMCCSN model with less second dredge-up results in a hydrodynamic and neutrino-induced NS kick of >40 km s−1 and a NS spin period of ∼30 ms, both not largely different from those of the Crab pulsar at birth.

The possibility of r-process in the core-collapse supernova of an ONeMg core

2003 ◽  
Vol 718 ◽  
pp. 638-640 ◽  
Author(s):  
M. Tamamura ◽  
S. Wanajo ◽  
N. Itoh ◽  
K. Nomoto ◽  
S. Nozawa
Keyword(s):  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Core ◽  
R Process
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