Triple alpha mechanism

This impasse was partly surmounted in 1952 by Edwin Saltpeter at Cornell University. His suggestion was that a triple alpha mechanism could provide a means of building nuclei beyond mass number 4, as summarized in the following equation ... 

Becausethe4He nucleus does not bind to either proton or neutron, it cannot be destroyed by interacting uuth either in stars. Another mechanism, theso-called triple alpha reaction alloius 4He to/use sloiuly into12 C at the cores 0/ red-giant stars. 

As shown by Equations (2.25) and (2.26), two He nuclei can fuse together to form Be, which in turn can fuse with another He nucleus to make a nuclide. Because the net reaction involves the fusion of three alpha particles, the first two steps in this mechanism are often called the triple alpha process (Figure 2.16). Because this is a three-body process, the reaction is slow, allowing Red Giant stars to continue to burn for 10 -10 years. Our sun will eventually become a Red Giant, swelling in size to engulf all of the inner planets. 

Saltpeter also suggested that the formed by both mechanisms (triple alpha and double alpha) could then go on to capture some further alpha particles to yield and °Ne in accordance with the observed higher abundances of these two particular isotopes. However, Saltpeter did not have much to say on the nature of what he labeled as and his theory created httle impression in the astrophysi-cal community. 

Owing to the last experimental and theoretical works in the study of the Orito reaction some insight in the mechanism of the reaction has been gained but full understanding has not yet been achieved. Therefore much more effort is needed in the future, especially in studying the role of the nature of the metal catalysts and the effects of triple intermediate complexes, [Metal-Modifier-Reactant], in enantioselectivity as shown in the case of the enantioselective hydrogenation of alpha-keio esters on tartaric acid modified Ni, Cu, and Co eatalysts... 

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