Stars fusion reactions

Helium, plentiful in the cosmos, is a product of the nuclear fusion reactions that are the prime source of stellar energy. The other members of the hehum-group gases are thought to have been created like other heavier elements by further nuclear condensation reactions occurring at the extreme temperatures and densities found deep within stars and in supernovas. 

Other fusion reactions such as D plus "He" and D plus D (not to mention the II plus II of stars) require far more difficult physical conditions than D plus T, but offer potential advantages in reduced neutron production, and even larger reseiwes of potential energy in the case of D-D. 

The sun and all other stars produce energy at a huge rate from sustained nuclear fusion. Over time, stars evolve through several stages, including stellar explosions. The products of a stellar explosion can form stars of more complex composition. Three distinct generations of stars have been identified, each fueled by a different set of fusion reactions. 

Mg+, He As a result of these and other fusion reactions, the star eventually contains... 

An a particle can abstract two electrons from some other atom or molecule (and given the extremely high ionization potential of helium, the highest of any atom, it would be difficult to prevent it) to become a helium atom. Helium also is a constituent in stars as a result of the fusion reaction... 

When helium fusion begins, the core of the star is stabilised and a new spherical equilibrium is set up. Gravitational contraction is balanced by the expansive pressure of heat levels maintained by nuclear fusion reactions. Oxygen is produced to the detriment of carbon via the reaction... 

The nuclear reactions in which tighter nuclei fuse together to form a heavier nuclear are called nuclear fusion reactions. Such reactions, occur at very high temperature (of the order of > 10 K) which exist only in the sun or interior of stars therefore, such reactions are also called thermonuclear reactions. 

Fusion reactions signify the formation of a true star. The fusion reactions balance the gravitational contraction and an equilibrium... 

Once a star s core temperature has reached about three billion degrees, fusion processes generate iron. And here they stop, because iron is the most stable nucleus of all. There is no energy to be gained by fusing iron nuclei. Yet heavier elements clearly do exist. They are created in the outer regions of the star, where neutrons emitted by fusion reactions are captured by nuclei to build all the elements up to bismuth (atomic number 73). 

Eventually, the helium of the star will be exhausted, leading to further gravitational collapse with a temperature increase to 6 x 108-2 x 109 K (kT 100-200 keV). At this point the fusion reactions of the a-cluster nuclei are possible. For example,... 

Fusion is what powers the Sun and stars. One type of fusion reaction involves the combination of two "heavy" isotopes of hydrogen. Isotopes of an element have the same number of protons, but a different number of neutrons. For example, hydrogen and its isotopes—deuterium and tritium—all have one proton in their nuclei. Remember that the number of protons plus the number of neutrons make up the mass of an atom. Because they have different numbers of neutrons, hydrogen, deuterium, and tritium have different masses. Deuterium has one proton and one neutron. It has a mass of 2 atomic mass units (amu). Deuterium can also be written as hydrogen-2. The number following the element s name is the isotope s mass. Tritium has one proton and two neutrons. So, tritium has a mass of 3 amu. Tritium can be written as hydrogen-3. 

Fusion reactions, or thermonuclear reactions, release amazing amounts of energy. Inside stars and the Sun, hydrogen atoms are constantly undergoing fusion reactions and giving off energy that we see as light and feel as heat. 

In the stable cores of the most massive stars, 42He2+ and other elements may fuse to produce heavier elements up to nonradioactive 5226Fe26+ (Faure, 1998, 13-18 Wallerstein et al 1997 Burbidge et al., 1957 Delsemme, 1998, 44). Radioactive 5628Ni28+ can form through the following helium fusion reaction ... 

Another source of radiation is space. As we know the energy of our sun and all other stars form nuclear fusion reactions. Not only heat and light but also nuclear radiation come to the Earth from space. This nuclear radiation is called cosmic rays or cosmic radiations . The earth s ozone layer usually absorbs these types of radiations. However, a very small quantity of cosmic rays reaches the Earth s surface. Briefly, it is not possible to get rid of radiation. 

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