Thorium transmutation

R. R. Liversage, Third-party verification of Cincinnati group s thorium transmutation process, Infinite Energy, 13-14 (Special Double Issue) (March-June 1997). 

Each of the elements has a number of isotopes (2,4), all radioactive and some of which can be obtained in isotopicaHy pure form. More than 200 in number and mosdy synthetic in origin, they are produced by neutron or charged-particle induced transmutations (2,4). The known radioactive isotopes are distributed among the 15 elements approximately as follows actinium and thorium, 25 each protactinium, 20 uranium, neptunium, plutonium, americium, curium, californium, einsteinium, and fermium, 15 each herkelium, mendelevium, nobehum, and lawrencium, 10 each. There is frequently a need for values to be assigned for the atomic weights of the actinide elements. Any precise experimental work would require a value for the isotope or isotopic mixture being used, but where there is a purely formal demand for atomic weights, mass numbers that are chosen on the basis of half-life and availabiUty have customarily been used. A Hst of these is provided in Table 1. 

Radon is the heaviest of the noble gases and is the only one that is radioactive. It is the decay product of radium, thorium, and uranium ores and rocks found underground. As it decays, it emits alpha particles (hehum nuclei) and is then transmuted to polonium and finally lead. The Earth s atmosphere is just 0.0000000000000000001% radon, but because radon is 7.5 times heavier than air, it can collect in basements and low places in buildings and homes. 

Radon s source is a step in the transmutation of several elements uranium —> thorium — radium —> radon —> polonium —> lead. (There are a number of intermediate decay products and steps involved in this process.) Radon-222 forms and collects just a few inches below the surface of the ground and is often found in trapped pockets of air. It escapes through porous soils and crevices. 

While studying radium, Friedrich Ernst Dorn (1848—1916) found that it gave off a radioactive gas that, when studied in more detail, proved to be the sixth noble gas. Dorn was given credit for its discovery in 1900. He called it radon, a variation of the word radium. Sir Wdham Ramsay and R. W. Whytlaw-Gray, who also investigated the properties of radon, called it niton from the Latin word nitens, which means shining. Several other scientists who worked with radon named it thoron because of the transmutation of radon-220 from the decay of thorium. However, since 1923, the gas has been known as radon because it is the radioactive decay gas of the element radium. The name is derived from the Latin word radius, which means ray. ... 

Twentieth Century Demargay discovers europium. Rutherford and Soddy discover thorium X. B. B. Boltwood, H. N. McCoy, and J. W. Strutt prove independently that radium is produced by spontaneous transmutation of uranium. 

III hen a radioactive nucleus emits an alpha or beta particle, the identity UU of the nucleus is changed because there is a change in atomic number. The changing of one element to another is called transmutation. Consider a uranium-238 nucleus, which contains 92 protons and 146 neutrons. When an alpha particle is ejected, the nucleus loses 2 protons and 2 neutrons. Because an element is defined by the number of protons in its nucleus, the 90 protons and 144 neutrons left behind are no longer identified as being uranium. What we have now is a nucleus of a different element—thorium. 

This equation shows that transmutes to the two elements written to the right of the arrow. When this transmutation happens, energy is released, partly in the form of gamma radiation and partly in the form of kinetic energy in the alpha particle (2He) and the thorium atom. In this and all other nuclear equations, the mass numbers balance (238 = 234 + 4) and the atomic numbers also balance (92 = 90 + 2). 

Recently much attention has been given to the accelerator driven systems, burning in inert matrices, and the use of thorium to burn plutonium. The concept of a closed nuclear fuel cycle was traditionally considered as transmutation (burning) of only plutonium and recycled uranium, with minor actinides (neptunium, americium, curium) destined for final geological disposal. But as time goes on, a new understanding is emerging reduction of the quantity of actinides would ease requirements for final repositories and make them relatively less expensive. 

Another fertile isotope is 90 Th. Upon capturing slow neutrons, thorium is transmuted to uranium-233, which, like uranium-235, is a fissionable isotope ... 

Radon was discovered in 1899 by the McGill University professors Ernest Rutherford and Robert Owens, who found that radioactive thorium produced radioactive gas. They named this gaseous substance thorium emanation, later to become thoron. It was found that radium gave off a similar emanation (radon), as did actinium (actinon), in 1900 and 1904, respectively. Once the structure of the atom and the elemental transmutation process became better understood, it was determined that thoron, radon, and actinon were different isotopes of the same element (radon)— °Rn, Rn, and Rn, respectively. 

Ironically, nuclear transmutations were taking place virtually under the noses of the alchemists (or nnder their feet), bnt they had neither the methods to detect nor the knowledge to use these happenings. The discovery of the nuclear transmutation process was closely linked to the discovery of radioactivity by Henri Becqnerel in 1896. Nnclear transmutations occnr dnring the spontaneous radioactive decay of naturally occurring thorium and uranium (atomic numbers 90 and 92, respectively) and the radioactive... 

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