#nuclear reaction

[saraichinwag]

What Happens When Plutonium Reacts with Uranium?

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[studychemistrytopics]

Nuclear Reaction - Definition, Types and Examples - Chemistry

Nuclear reaction in physics and chemistry, examples formula, equations of artificial transmutation of elements, nuclear fission or fusion types of reactions

[studychemistrytopics]

Nuclear Fission - Process, Definition, History, Uses, Examples

Nuclear fission definition, history, examples in nucluear reactor, atomic bomb, uses of fission of heavy nucleus and fusion reaction in chemistry

[studychemistrytopics]

Nuclear Fusion - Facts, Definition, Uses, Equation, Energy

Nuclear fusion definition, facts, uses, equation and working process, fusion energy from mass defect, source of steller energy in sun or star

[studychemistrytopics]

Nuclear Reaction - Definition, Types and Examples - Chemistry

Nuclear reaction in physics and chemistry, examples formula, equations of artificial transmutation of elements, nuclear fission or fusion types of reactions

[kazuyuki-sekizawa]

Measuring Zeptoseconds: a Milestone Toward the Synthesis of Unknown Elements

A world-wide collaboration of experimental and theoretical nuclear physicists deduced interaction times of two colliding atomic nuclei, which contain crucial information for the synthesis of the yet-unknown element, No. 120. Discovering a new element has significant meaning, not only as a fundamental science of nuclear physics and chemistry, as it results in the naming right, which will be coined on the Periodic Table forever. So far, researchers have successfully synthesized so-called super-heavy elements (SHEs) up to atomic No. 118, oganesson, by colliding (and “merging”) a calcium isotope, 48Ca, with an actinide nucleus, known as “hot fusion” reaction. In order to synthesize the yet-unknown elements, 119, 120, and beyond, the use of a heavier projectile than 48Ca is unavoidable. However, little was known about to what extent the reaction is altered by the change of the projectile nucleus. In the Letter, researchers put a great step forward. Two experimental campaigns were carried out at the Heavy Ion Accelerator Facility operated by the Australian National University in Canberra, Australia, where a counterpart of fusion, i.e., re-separated fragments, was studied in great detail. Fragments’ mass and angle distributions were measured, for the first time, for four SHE-formation reactions with a wide angular coverage. From the analysis of rotation angles, the researchers deduced how long two nuclei play “tango”―it lasts only over a thousandth of a billionth of a billionth of seconds (zeptoseconds)! Among the four systems examined, it is found that a collision of titanium and californium isotopes, 50Ti+249Cf, exhibits longest sticking time and is the most promising reaction for the synthesis of the element 120.

This is an outreach summary to our article: Zeptosecond contact times for element Z=120 synthesis Phys. Lett. B 808, 135626 (2020) by H.M. Albers, J. Khuyagbaatar, D.J. Hinde, I.P. Carter, K.J. Cook, M. Dasgupta, Ch.E. Düllmann, K. Eberhardt, D.Y. Jeung, S. Kalkal, B. Kindler, N.R. Lobanov, B. Lommel, C. Mokry, E. Prasad, D.C. Rafferty, J. Runke, K. Sekizawa, C. Sengupta, C. Simenel, E.C. Simpson, J.F. Smith, P. Thörle-Pospiech, N. Trautmann, K. Vo-Phuoc, J. Walshe, E. Williams, and A. Yakushev

DOI: 10.1016/j.physletb.2020.135626

[kazuyuki-sekizawa]

Bright Future Ahead: Achievement in Nuclear Reaction Theory

A newly developed theory explains the production mechanism of a whole set of abundant isotopes in collisions of two atomic nuclei. Production of yet-unknown, unstable nuclei is of paramount importance to answer fundamental questions: Do existing models properly describe physics of extremely unstable nuclei? How were the elements heavier than iron produced in the Universe? What is the heaviest element in nature? However, the production at laboratories is not easy and obvious, and a reliable theoretical prediction is mandatory. In the paper, researchers put a great step forward. They have newly developed a theoretical framework that combines 1) a state-of-the-art quantum many-body theory that incorporates with quantal fluctuations, called Stochastic Mean Field (SMF) theory, with 2) an elaborated statistical model that describes secondary decays (particle evaporation and fission) of produced “hot” fragments. With the hybrid theory it is shown that a complete set of experimental data for collisions of nickel and lead nuclei can be reproduced non-empirically, without adjustable parameters―it makes the theory distinctive and special as compared to many other phenomenological models on the market. The predictive theory will lead us to terra incognita―bright future ahead for nuclear experiments.

Movie: Real-time density evolution in the reaction plane for a collision of Nickel-64 with Lead-208 at Ecm=268 MeV with L=50 hbar.

Figure: Comparison of secondary production cross sections between experimental data (red points) and the new (blue line) and previous (red line) theories.

This article is an outreach summary of our paper: K. Sekizawa and S. Ayik, Quantal diffusion approach for multinucleon transfer processes in the 58,64Ni+208Pb reactions: Toward the production of unknown neutron-rich nuclei, Phys. Rev. C 102, 014620 (2020).

DOI: 10.1103/PhysRevC.102.014620

arXiv:2003.07786 [nucl-th] (https://arxiv.org/abs/2003.07786)

Supplemental Movies (Link to a YouTube Playlist)