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Hasil Pencarian

Ditemukan 2 dokumen yang sesuai dengan query
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Riza Ibnu Adam
"[ABSTRAK
Di permukaan bintang neutron, perubahan kerapatan partikel yang signi kan dapat
menghasilkan separasi muatan dalam bentuk lapisan dipol listrik. Pada penelitian
ini dipelajari efek medan listrik akibat lapisan tersebut terhadap properti dari bintang
neutron. Untuk memodelkan kerapatan lapisan dipol listrik, kami menggunakan
dua fungsi Gaussian. Pada perhitungan ini kami gunakan dua model dengan
asumsi berbeda, yakni: model dengan asumsi bahwa bintang neutron hanya tersusun
atas p, n, e dan  serta model dengan asumsi bintang neutron tersusun dari p, n, e,
 dan hyperon. Hasil yang diperoleh menunjukkan bahwa massa maksimum tidak
sensitif terhadap medan listrik di permukaan, tetapi radius bintang dengan massa
kanonik 1:4Mb cukup sensitif terhadap medan listrik. Bintang neutron dengan
hyperon bersifat lebih soft dibandingkan bintang neutron tanpa hyperon

ABSTRACT
On the surface of a neutron star, a signi cant particle density changes can produce
charge separation in the form electric dipole layer. This research studied electric
eld e ect from the dipole layer on the properties of neutron star. For modeling
electric dipole layer density, we use two Gaussian functions. We use two models
with di erent assumptions: namely a model which assumes the neutron star is only
composed of p, n, e and  and a model which assumes the neutron star is composed of
p, n, e,  and hyperon. The result showes that the maximum mass is not sensitive to
the electric elds on the surface, but the radius of star with canonical mass 1:4Mb
is quite sensitive to electric elds. The neutron star with hyperon is softer than
without hyperon;On the surface of a neutron star, a signi cant particle density changes can produce
charge separation in the form electric dipole layer. This research studied electric
eld e ect from the dipole layer on the properties of neutron star. For modeling
electric dipole layer density, we use two Gaussian functions. We use two models
with di erent assumptions: namely a model which assumes the neutron star is only
composed of p, n, e and  and a model which assumes the neutron star is composed of
p, n, e,  and hyperon. The result showes that the maximum mass is not sensitive to
the electric elds on the surface, but the radius of star with canonical mass 1:4Mb
is quite sensitive to electric elds. The neutron star with hyperon is softer than
without hyperon, On the surface of a neutron star, a signi cant particle density changes can produce
charge separation in the form electric dipole layer. This research studied electric
eld e ect from the dipole layer on the properties of neutron star. For modeling
electric dipole layer density, we use two Gaussian functions. We use two models
with di erent assumptions: namely a model which assumes the neutron star is only
composed of p, n, e and  and a model which assumes the neutron star is composed of
p, n, e,  and hyperon. The result showes that the maximum mass is not sensitive to
the electric elds on the surface, but the radius of star with canonical mass 1:4Mb
is quite sensitive to electric elds. The neutron star with hyperon is softer than
without hyperon]"
2015
T43805
UI - Tesis Membership  Universitas Indonesia Library
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Alpi Mahisha Nugraha
"Fenomena halo neutron dalam nuklir digambarkan adanya kemunculan ’ekor’ dan adanya ’ruang kosong’ antara core dan ekor pada distribusi neutron akibat energi ikat yang lemah. Metode analisa halo yang dikembangkan oleh V. Rotival dkk [Phys. Rev. C79, 054308 (2009)] untuk menghitung besaran-besaran halo berdasarkan model Hartree-Fock-Bogoulibov (HFB) pada isotop Cr dan isotop Sn menjadi salah satu alternatif untuk mempelajari fenomena halo. Berbeda dengan Rotival dkk, kami menggunakan model Relativistic Mean Field (RMF) pada penelitian ini. Berbeda dengan hasil perhitungan berdasarkan model HFB, kami fokus mengamati perilaku spektrum single particle energy level 1g9~2 terhadap kemunculan halo pada isotop Cr. Selain itu, pada penelitian ini kami juga memperlajari dampak dari suku cross coupling meson ω − ρ, suku-suku tensor dan suku pertukaran elektromagnetik pada model RMF terhadap kemunculan halo pada isotop Cr dan isotop Sn. Hasil perhitungan prediksi kemunculan halo berdasarkan model RMF lebih besar dibandingkan dengan hasil perhitungan berdasarkan model HFB (⟨Nhalo⟩RMF > ⟨Nhalo⟩HFB).

In neutron halo phenomenon, the neutron density displays an unusually extended ’tail’ and ’empty space’ between the core and the tail due to weak binding energy. New analysis method of the halo was developed by V. Rotival, et al.[Phys. Rev. C79, 054308 (2009)] in Cr-isotopes and Sn-isotopes, its usually applied with Hartree-Fock-Bogoliubov (HFB) model. Unlike them, we use the model of the Relativistic Mean Field (RMF) in this research. We observed different behavior at the level 1g9~2 in line with appearance of halo in Cr-isotopes. Moreover, in this research we also studied the effects of cross coupling meson ω − ρ, tensor, and electromagnetic exchange in RMF model appearance of halo in Cr-isotopes and Sn-isotopes. The prediction of the existence of halo based on RMF model is greater than the prediction based on HFB model (⟨Nhalo⟩RMF > ⟨Nhalo⟩HFB).
"
Depok: Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2015
T43785
UI - Tesis Membership  Universitas Indonesia Library