Nukleosintesis: Perbedaan antara revisi

 

Nukleosintesis eksplosif melibatkan [[nukleosintesis supernova]], dan menghasilkan unsur-unsur yang lebih berat daripada besi oleh suatu hamburan reaksi nuklir yang intensif yang biasanya berlangsung hanya dalam beberapa detik pada peristiwa ledakan inti supernova. Di dalam lingkungan supernova yang penuh ledakan, unsur-unsur antara [[silikon]] dan nikel disintesis oleh fusi yang cepat. Juga di dalam [[supernova]], proses lanjut nukleosintesis dapat terjadi, seperti [[proses r]], di mana isotop-isotop yang paling banyak neutronnya dari unsur-unsur yang lebih berat daripada nikel dihasilkan oleh penyerapan yang cepat dari [[neutron]] bebas yang dilepaskan ketika ledakan terjadi. Kejadian ini bertanggung jawab atas gugus alami unsur-unsur radioaktif, seperti [[uranium]] dan [[torium]], juga isotop-isotop yang paling banyak neutronnya dari unsur-unsur berat.

 

Explosive nucleosynthesis occurs too rapidly for radioactive decay to increase the number of neutrons, so that many abundant isotopes having equal even numbers of protons and neutrons are synthesized by the [[alpha process]] to produce nuclides which consist of whole numbers of helium nuclei, up to 16 (representing ⁶⁴Ge). Such nuclides are stable up to ⁴⁰Ca (made of 10 helium nuclei), but heavier nuclei with equal numbers of protons and neutrons are radioactive. However, the alpha process continues to influence production of [[isobar]]s of these nuclides, including at least the radioactive nuclides ⁴⁴Ti , ⁴⁸Cr , ⁵²Fe , ⁵⁶Ni , ⁶⁰Zn, and ⁶⁴Ge, most of which (save ⁴⁴Ti and ⁶⁰Zn) are created in such abundance as to decay after the explosion to create the most abundant stable isotope of the corresponding element at each atomic weight. Thus, the corresponding most common (abundant) isotopes of elements produced in this way are ⁴⁸Ti , ⁵²Cr , ⁵⁶Fe , and ⁶⁴Zn. Many such decays are accompanied by emission of gamma-ray lines capable of identifying the isotope that has just been created in the explosion.