Triple alpha process

Triple-alpha process The nuclear process resulting in the fusion of three He nuclei or alpha particles to form 12C. 

Figure 3.2 In the triple alpha process, three helium nuclei collide to eventually produce carbon. This process occurs in extremely hot stars.

Because three a-particles combine to form 12C, this process is known as the triple-alpha process. Oxygen-16 is also produced during helium burning through the reaction 12C(a,y)160. 

The triple-alpha process is possible in the dense cores of massive stars. The process involves the essentially simultaneous fusion of three 42He2+ to form 126C6+ (Faure, 1998, 17-18). As the first step ... 

Triple-alpha process The formation of a carbon-12 nucleus in the interior of a massive star through the essentially simultaneous fusion of three helium nuclei. 

Helium normally has two protons, two neutrons, and two electrons. An alpha particle is another name for the positively charged nucleus of the helium-4 atom. Alpha particles are emitted by some radioactive substances. But let me clarify why the triple-alpha process is so difficult and so wonderful. Triple-alpha process says Miss Muxdroozol. 

But there s some bad news. The speed of the two-step triple-alpha process to produce carbon depends on how much beryllium-8 resides in a star to be slammed into. And, we know that there is only one nucleus of beryllium-8 for every billion nuclei of helium. A very tiny amount According to astronomers ... 

This is what they thought at first. I m giving you a bit of history here. The reaction of beryllium-8 and helium-4 seemed too slow. There was one chance that the reaction speed could be boosted—if carbon-12 had a very special property an energy almost exactly equal to the combined energy of beryllium-8 and helium-4 at temperatures in a red giant. Chemists called this kind of facilitated nuclear reaction resonant. If by some miracle this were true, then the triple-alpha process could work. ... 

Okay, I ve showed you how a fortuitous two-step triple-alpha process can create carbon-12. But what happens if another helium-4 slams into the carbon-12 No answer, Mr. Plex Okay, I ll tell you. The carbon-12 is converted to oxygen-16. ... 

This book is dedicated to the triple alpha process and the number 7.6549 the reasons we are alive today, and smiling, on Earth. 

Primary nucleosynthesis Some astronomical evidence suggests that 13C nucleosynthesis has a primary component that is, a production rate in stars that does not rely on the prior presence of carbon in the interstellar gas from which the stars formed (see below). This is attested to by nitrogen also having a primary component (see 14N). This can occur in a red AGB star, which is creating new 12C by the triple-alpha process in a helium-burning shell beneath its H-containing envelope. Such stars undergo... 

H.Oberhummer, A. Csoto and H. Schlattl. Fine tuning the basic forces of nature through the triple alpha process in red giant stars. Science, 289, 88 (2000). 

Fig. 11. Triple alpha process of 12C synthesis. In the first step a small amount of sBe nuclei builds up in equilibrium with its decay products (forward and backward reactions involve alpha particles). The second step involves a capture of another alpha particle by the unstable sBe nucleus which proceeds via an s-wave resonance state in the product nucleus 12 C located close to the Gamow energy window for temperatures indicated schematically by the three-way arrows on the right...

The beryllium 8 isotope is produced in the collapse of massive red-giant stars via the triple-alpha process. Initially two helium nuclei—or alpha particles—fuse to form an unstable and very short-lived state of beryllium, as expressed by the following reaction ... 

A less el3 dent, but more reliable source of interstellar oxygen originates in the red-giant phase of stars, which occurs after the useable hydrogen has fused to helium in the core (see chapter 2). In this stage, the so-called triple-alpha process produces but a side effect is that the carbon can interact with the available helium nuclei, so that... 

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. 

Schematic diagram illustrating the triple alpha process that occurs during stellar nucleosynthesis. [Attributed to Borb, reproduced from https //en.

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