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Cold Fission
Cold fission or cold nuclear fission is defined as involving fission events for which fission fragments have such low excitation energy that no neutrons or gammas are emitted. Cold fission events have so low a probability of occurrence that it is necessary to use a high-flux nuclear reactor to study them. According to research first published in 1981, the first observation of cold fission events was in experiments on fission induced by thermal neutrons of uranium 233, uranium 235, and plutonium 239 using the High Flux Reactor at the Institut Laue-Langevin in Grenoble, France. Other experiments on cold fission were also done involving 248Cm and 252Cf. A unified approach of cluster decay, alpha decay and cold fission was developed by Dorin N. Poenaru et al. A phenomenological interpretation was proposed by Gönnenwein and Duarte ''et al.'' The importance of cold fission phenomena lies in the fact that fragments reaching detectors have the same mass that they obtained at the "sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fission
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay. Nuclear fission of heavy elements was discovered on Monday 19 December 1938, by German chemist Otto Hahn and his assistant Fritz Strassmann in cooperation with Austrian-Swedish physicist Lise Meitner. Hahn understood that a "burst" of the atomic nuclei had occurred. Meitner explained it theoretically in January 1939 along with her nephew Otto Robert Frisch. Frisch named the process by analogy with biological fission of living cells. For heavy nuclides, it is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). Like nuclear fusion, for fission to produce energy, the total binding energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Decay
Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a different atomic nucleus, with a mass number that is reduced by four and an atomic number that is reduced by two. An alpha particle is identical to the nucleus of a helium-4 atom, which consists of two protons and two neutrons. It has a charge of and a mass of . For example, uranium-238 decays to form thorium-234. While alpha particles have a charge , this is not usually shown because a nuclear equation describes a nuclear reaction without considering the electrons – a convention that does not imply that the nuclei necessarily occur in neutral atoms. Alpha decay typically occurs in the heaviest nuclides. Theoretically, it can occur only in nuclei somewhat heavier than nickel (element 28), where the overall binding energy per nucleon is no longer a maximum and the nuclides are therefore unstable toward spontaneou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Chemistry
Nuclear chemistry is the sub-field of chemistry dealing with radioactivity, nuclear processes, and transformations in the nuclei of atoms, such as nuclear transmutation and nuclear properties. It is the chemistry of radioactive elements such as the actinides, radium and radon together with the chemistry associated with equipment (such as nuclear reactors) which are designed to perform nuclear processes. This includes the corrosion of surfaces and the behavior under conditions of both normal and abnormal operation (such as during an nuclear accidents, accident). An important area is the behavior of objects and materials after being placed into a nuclear waste storage or disposal site. It includes the study of the chemical effects resulting from the absorption of radiation within living animals, plants, and other materials. The radiation chemistry controls much of radiation biology as radiation has an effect on living things at the molecular scale. To explain it another way, the rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Fusion
Cold fusion is a hypothesized type of nuclear reaction that would occur at, or near, room temperature. It would contrast starkly with the "hot" fusion that is known to take place naturally within stars and artificially in hydrogen bombs and prototype fusion reactors under immense pressure and at temperatures of millions of degrees, and be distinguished from muon-catalyzed fusion. There is currently no accepted theoretical model that would allow cold fusion to occur. In 1989, two electrochemists, Martin Fleischmann and Stanley Pons, reported that their apparatus had produced anomalous heat ("excess heat") of a magnitude they asserted would defy explanation except in terms of nuclear processes. They further reported measuring small amounts of nuclear reaction byproducts, including neutrons and tritium. ("It is inconceivable that this mount of heatcould be due to anything but nuclear processes... We realise that the results reported here raise more questions than they provide a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleon Pair Breaking
Nucleon pair breaking in fission has been an important topic in nuclear physics for decades. "Nucleon pair" refers to nucleon pairing effects which strongly influence the nuclear properties of a nuclide. The most measured quantities in research on nuclear fission are the charge and mass fragments yields for uranium-235 and other fissile nuclides. In this sense, experimental results on charge distribution for low-energy fission of actinides present a preference to an even ''Z'' fragment, which is called odd-even effect on charge yield. The importance of these distributions is because they are the result of rearrangement of nucleons on the fission process due to the interplay between collective variables and individual particle levels; therefore they permit to understand several aspects of dynamics of fission process. The process from saddle (when nucleus begins its irreversible evolution to fragmentation) to scission point (when fragments are formed and nuclear interaction betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coulomb Interaction
Coulomb's inverse-square law, or simply Coulomb's law, is an experimental law of physics that quantifies the amount of force between two stationary, electrically charged particles. The electric force between charged bodies at rest is conventionally called ''electrostatic force'' or Coulomb force. Although the law was known earlier, it was first published in 1785 by French physicist Charles-Augustin de Coulomb, hence the name. Coulomb's law was essential to the development of the theory of electromagnetism, maybe even its starting point, as it made it possible to discuss the quantity of electric charge in a meaningful way. The law states that the magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them. Coulomb studied the repulsive force between bodies having electrical charges of the same sign: Coulomb also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Greiner
Walter Greiner (29 October 1935 – 6 October 2016) was a German theoretical physicist. His research interests lay in atomic physics, heavy ion physics, nuclear physics, elementary particle physics (particularly in quantum electrodynamics and quantum chromodynamics). He is known for his series of books in theoretical physics, particularly in Germany but also around the world. Biography Greiner was born on 29 October 1935, in Neuenbau, Sonnenberg, Germany. He studied physics at the University of Frankfurt (Goethe University Frankfurt), receiving a BSci in physics, a master's degree in 1960 with a thesis on Plasma-reactors, and a PhD in 1961 at the University of Freiburg under , with a thesis on the nuclear polarization in μ-mesic atoms. From 1962 to 1964, he was assistant professor at the University of Maryland, followed by a Research Associate position at the University of Freiburg in 1964. Starting in 1965, he became a full professor at the Institute for Theoretical Physics at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorin N Poenaru
Dorin Mircea Stelian Poenaru (born April 9, 1936, Suiug, Bihor County) is a Romanian nuclear physicist and engineer. He contributed to the theory of heavy particle radioactivity ( cluster decay). Education Poenaru completed his higher education at the Emanuil Gojdu National College in Oradea where in 1953 he received a diploma of merit. After passing the entrance examination, he studied at the Faculty of Electronics and Telecommunication of Politehnica University of Bucharest from which he graduated in 1958. In 1971, he received a B.A. in theoretical physics from the University of Bucharest while working in electronic engineering at the Institute of Atomic Physics (IFA) of the Romanian Academy in Măgurele, near Bucharest. He received his Ph.D. in Nuclear Electronics, from Politehnica University in 1968. He received a second Ph.D. in Theoretical Physics from the Central Institute of Physics, Bucharest in 1980. Academic career *1958–1962 Electronic engineer, Institu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorin N
Dorin may refer to: ; Romanian masculine given name *Dorin Chirtoacă *Dorin Dănilă *Dorin DrăguÈ›anu *Dorin Goian *Dorin Recean *Dorin Rotariu *Dorin Tudoran ; Surname *Françoise Dorin (1928–2018), French actor, comedian, novelist, playwright and songwriter; daughter of René *René Dorin René Dorin (13 November 1891,Luc Antonini, ÂFrançoise Dorin, de la chanson au roman», ''Généalogie Magazine n° 301'', March 2010. La Rochelle – 25 July 1969, Noisy-le-Grand) was a 20th-century French chansonnier, screenwriter and playwrigh ... (1891-1969), French chansonnier, screenwriter and playwright {{given name, type=both Romanian masculine given names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cluster Decay
Cluster decay, also named heavy particle radioactivity or heavy ion radioactivity, is a rare type of nuclear decay in which an atomic nucleus emits a small "cluster" of neutrons and protons, more than in an alpha particle, but less than a typical binary fission fragment. Ternary fission into three fragments also produces products in the cluster size. The loss of protons from the parent nucleus changes it to the nucleus of a different element, the daughter, with a mass number ''A''d = ''A'' − ''A''e and atomic number ''Z''d = ''Z'' − ''Z''e, where ''A''e = ''N''e + ''Z''e. For example: : → + This type of rare decay mode was observed in radioisotopes that decay predominantly by alpha emission, and it occurs only in a small percentage of the decays for all such isotopes. The branching ratio with respect to alpha decay is rather small (see the Table below). :B = T_a / T_c Ta and Tc are the half-lives of the parent nucleus relative to alpha decay and cluster radioactivity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
