In astrophysics and nuclear physics, nuclear pasta is a theoretical type of degenerate matter that is postulated to exist within the crusts of neutron stars. If it exists, nuclear pasta would be the strongest material in the universe.[1] Between the surface of a neutron star and the quark–gluon plasma at the core, at matter densities of 1014 g/cm3, nuclear attraction and Coulomb repulsion forces are of comparable magnitude. The competition between the forces leads to the formation of a variety of complex structures assembled from neutrons and protons. Astrophysicists call these types of structures nuclear pasta because the geometry of the structures resembles various types of pasta.[2][3]
Neutron stars form as remnants of massive stars after a supernova event. Unlike their progenitor star, neutron stars do not consist of a gaseous plasma. Rather, the intense gravitational attraction of the compact mass overcomes the electron degeneracy pressure and causes electron capture to occur within the star. The result is a compact ball of nearly pure neutron matter with sparse protons and electrons interspersed, filling a space several thousand times smaller than the progenitor star.[4]
At the surface, the pressure is low enough that conventional nuclei, such as helium and iron, can exist independently of one another and are not crushed together due to the mutual Coulomb repulsion of their nuclei.[5] At the core, the pressure is so great that this Coulomb repulsion cannot support individual nuclei, and some form of ultra-dense matter, such as the theorized quark–gluon plasma, should exist.[citation needed]
The presence of a small population of protons is essential to the formation of nuclear pasta. The nuclear attraction between protons and neutrons is greater than the nuclear attraction of two protons or two neutrons. Similar to how neutrons act to stabilize heavy nuclei of conventional atoms against the electric repulsion of the protons, the protons act to stabilize the pasta phases. The competition between the electric repulsion of the protons, the attractive force between nuclei, and the pressure at different depths in the star lead to the formation of nuclear pasta.[6]
Phasesedit
While nuclear pasta has not been observed in a neutron star, its phases are theorized to exist in the inner crust of neutron stars, forming a transition region between the conventional matter at the surface and the ultra-dense matter at the core. All phases are expected to be amorphous, with a heterogeneous charge distribution.[2] Towards the top of this transition region, the pressure is great enough that conventional nuclei will be condensed into much more massive semi-spherical collections. These formations would be unstable outside the star, due to their high neutron content and size, which can vary between tens and hundreds of nucleons. This semispherical phase is known as the gnocchi phase.[7]
When the gnocchi phase is compressed, as would be expected in deeper layers of the crust, the electric repulsion of the protons in the gnocchi is not fully sufficient to support the existence of the individual spheres, and they are crushed into long rods, which, depending on their length, can contain many thousands of nucleons. These rods are known as the spaghetti phase. Further compression causes the spaghetti phase rods to fuse and form sheets of nuclear matter called the lasagna phase. Further compression of the lasagna phase yields the uniform nuclear matter of the outer core. Progressing deeper into the inner crust, those holes in the nuclear pasta change from being cylindrical, called by some the bucatini phase or antispaghetti phase, into scattered spherical holes, which can be called the Swiss cheese phase.[6] The nuclei disappear at the crust–core interface, transitioning into the liquid neutron core of the star.
The pasta phases also have interesting topological properties characterized by homology groups.[8]
For a typical neutron star of 1.4 solar masses (M☉) and 12 km radius, the nuclear pasta layer in the crust can be about 100 m thick and have a mass of about 0.01 M☉. In terms of mass, this is a significant portion of the crust of a neutron star.[9][10]
Look up nuclear pasta in Wiktionary, the free dictionary.
Referencesedit
^Caplan, M. E.; Schneider, A. S.; Horowitz, C. J. (24 September 2018). "Elasticity of Nuclear Pasta". Physical Review Letters. 121 (13): 132701. arXiv:1807.02557. Bibcode:2018PhRvL.121m2701C. doi:10.1103/PhysRevLett.121.132701. PMID 30312063. S2CID 206317364. Retrieved 26 August 2021.
^ abPons, José A.; Viganò, Daniele; Rea, Nanda (2013). "Too much "pasta" for pulsars to spin down". Nature Physics. 9 (7): 431–434. arXiv:1304.6546. Bibcode:2013NatPh...9..431P. doi:10.1038/nphys2640. S2CID 119253979.
^Reagan, David. . Advanced Visualization Lab, Research Technologies, Indiana University. Archived from the original on April 4, 2020. Retrieved 28 June 2013.
^Nuclear Physics Panel; Physics Survey Committee; Board on Physics and Astronomy; Commission on Physical Sciences, Mathematics, and Applications, Division on Engineering and Physical Sciences (1 January 1986). Nuclear Physics. National Academies Press. pp. 111–. ISBN978-0-309-03547-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
^ abSchneider, A. S.; Horowitz, C. J.; Hughto, J.; Berry, D. K. (2013-12-20). "Nuclear Pasta Formation". Physical Review C. 88 (6): 065807. arXiv:1307.1678. doi:10.1103/PhysRevC.88.065807. ISSN 0556-2813.
^Kycia, Radosław A.; Kubis, Sebastian; Wójcik, Włodzimierz (2017-08-14). "Topological analysis of nuclear pasta phases". Physical Review C. 96 (2): 025803. arXiv:1709.07521. Bibcode:2017PhRvC..96b5803K. doi:10.1103/PhysRevC.96.025803. ISSN 2469-9985. S2CID 119352018.
^Kycia, Radosław A.; Kubis, Sebastian; Wójcik, Włodzimierz (2017-08-14). "Topological analysis of nuclear pasta phases". Physical Review C. 96 (2): 025803. arXiv:1709.07521. Bibcode:2017PhRvC..96b5803K. doi:10.1103/PhysRevC.96.025803. ISSN 2469-9985. S2CID 119352018.
^Peter Höflich; Pawan Kumar; J. Craig Wheeler (16 December 2004). Cosmic Explosions in Three Dimensions: Asymmetries in Supernovae and Gamma-Ray Bursts. Cambridge University Press. pp. 288–. ISBN978-1-139-45661-6.
^Yakovlev, D. G. (2015). "Electron transport through nuclear pasta in magnetized neutron stars". Monthly Notices of the Royal Astronomical Society. 453 (1): 581–590. arXiv:1508.02603. Bibcode:2015MNRAS.453..581Y. doi:10.1093/mnras/stv1642.
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In astrophysics and nuclear physics nuclear pasta is a theoretical type of degenerate matter that is postulated to exist within the crusts of neutron stars If it exists nuclear pasta would be the strongest material in the universe 1 Between the surface of a neutron star and the quark gluon plasma at the core at matter densities of 1014 g cm3 nuclear attraction and Coulomb repulsion forces are of comparable magnitude The competition between the forces leads to the formation of a variety of complex structures assembled from neutrons and protons Astrophysicists call these types of structures nuclear pasta because the geometry of the structures resembles various types of pasta 2 3 Cross section of neutron star Contents 1 Formation 1 1 Phases 2 See also 3 ReferencesFormation editNeutron stars form as remnants of massive stars after a supernova event Unlike their progenitor star neutron stars do not consist of a gaseous plasma Rather the intense gravitational attraction of the compact mass overcomes the electron degeneracy pressure and causes electron capture to occur within the star The result is a compact ball of nearly pure neutron matter with sparse protons and electrons interspersed filling a space several thousand times smaller than the progenitor star 4 At the surface the pressure is low enough that conventional nuclei such as helium and iron can exist independently of one another and are not crushed together due to the mutual Coulomb repulsion of their nuclei 5 At the core the pressure is so great that this Coulomb repulsion cannot support individual nuclei and some form of ultra dense matter such as the theorized quark gluon plasma should exist citation needed The presence of a small population of protons is essential to the formation of nuclear pasta The nuclear attraction between protons and neutrons is greater than the nuclear attraction of two protons or two neutrons Similar to how neutrons act to stabilize heavy nuclei of conventional atoms against the electric repulsion of the protons the protons act to stabilize the pasta phases The competition between the electric repulsion of the protons the attractive force between nuclei and the pressure at different depths in the star lead to the formation of nuclear pasta 6 Phases edit While nuclear pasta has not been observed in a neutron star its phases are theorized to exist in the inner crust of neutron stars forming a transition region between the conventional matter at the surface and the ultra dense matter at the core All phases are expected to be amorphous with a heterogeneous charge distribution 2 Towards the top of this transition region the pressure is great enough that conventional nuclei will be condensed into much more massive semi spherical collections These formations would be unstable outside the star due to their high neutron content and size which can vary between tens and hundreds of nucleons This semispherical phase is known as the gnocchi phase 7 When the gnocchi phase is compressed as would be expected in deeper layers of the crust the electric repulsion of the protons in the gnocchi is not fully sufficient to support the existence of the individual spheres and they are crushed into long rods which depending on their length can contain many thousands of nucleons These rods are known as the spaghetti phase Further compression causes the spaghetti phase rods to fuse and form sheets of nuclear matter called the lasagna phase Further compression of the lasagna phase yields the uniform nuclear matter of the outer core Progressing deeper into the inner crust those holes in the nuclear pasta change from being cylindrical called by some the bucatini phase or antispaghetti phase into scattered spherical holes which can be called the Swiss cheese phase 6 The nuclei disappear at the crust core interface transitioning into the liquid neutron core of the star The pasta phases also have interesting topological properties characterized by homology groups 8 For a typical neutron star of 1 4 solar masses M and 12 km radius the nuclear pasta layer in the crust can be about 100 m thick and have a mass of about 0 01 M In terms of mass this is a significant portion of the crust of a neutron star 9 10 See also editNeutron star merger nbsp Look up nuclear pasta in Wiktionary the free dictionary References edit Caplan M E Schneider A S Horowitz C J 24 September 2018 Elasticity of Nuclear Pasta Physical Review Letters 121 13 132701 arXiv 1807 02557 Bibcode 2018PhRvL 121m2701C doi 10 1103 PhysRevLett 121 132701 PMID 30312063 S2CID 206317364 Retrieved 26 August 2021 a b Pons Jose A Vigano Daniele Rea Nanda 2013 Too much pasta for pulsars to spin down Nature Physics 9 7 431 434 arXiv 1304 6546 Bibcode 2013NatPh 9 431P doi 10 1038 nphys2640 S2CID 119253979 Reagan David Visualizations of Nuclear Pasta Advanced Visualization Lab Research Technologies Indiana University Archived from the original on April 4 2020 Retrieved 28 June 2013 Nuclear Physics Panel Physics Survey Committee Board on Physics and Astronomy Commission on Physical Sciences Mathematics and Applications Division on Engineering and Physical Sciences 1 January 1986 Nuclear Physics National Academies Press pp 111 ISBN 978 0 309 03547 7 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Beskin Vasilii S 1999 Radio pulsars Physics Uspekhi 42 11 1173 1174 Bibcode 1999PhyU 42 1071B doi 10 1070 pu1999v042n11ABEH000665 S2CID 250831196 a b Schneider A S Horowitz C J Hughto J Berry D K 2013 12 20 Nuclear Pasta Formation Physical Review C 88 6 065807 arXiv 1307 1678 doi 10 1103 PhysRevC 88 065807 ISSN 0556 2813 Kycia Radoslaw A Kubis Sebastian Wojcik Wlodzimierz 2017 08 14 Topological analysis of nuclear pasta phases Physical Review C 96 2 025803 arXiv 1709 07521 Bibcode 2017PhRvC 96b5803K doi 10 1103 PhysRevC 96 025803 ISSN 2469 9985 S2CID 119352018 Kycia Radoslaw A Kubis Sebastian Wojcik Wlodzimierz 2017 08 14 Topological analysis of nuclear pasta phases Physical Review C 96 2 025803 arXiv 1709 07521 Bibcode 2017PhRvC 96b5803K doi 10 1103 PhysRevC 96 025803 ISSN 2469 9985 S2CID 119352018 Peter Hoflich Pawan Kumar J Craig Wheeler 16 December 2004 Cosmic Explosions in Three Dimensions Asymmetries in Supernovae and Gamma Ray Bursts Cambridge University Press pp 288 ISBN 978 1 139 45661 6 Yakovlev D G 2015 Electron transport through nuclear pasta in magnetized neutron stars Monthly Notices of the Royal Astronomical Society 453 1 581 590 arXiv 1508 02603 Bibcode 2015MNRAS 453 581Y doi 10 1093 mnras stv1642 Portals nbsp Physics nbsp Astronomy nbsp Stars nbsp Spaceflight nbsp Outer space nbsp Solar System nbsp Science Retrieved from https en wikipedia org w index php title Nuclear pasta amp oldid 1189578700, wikipedia, wiki, book, books, library,
