Question

Please answer both parts

Q.1

a) What is triple alpha process ? (50 words)

b) why is a temperature of 10^8 K is required for the initiation of the triple alpha process . Especially the first two steps , explain briefely with equations and values in 150-200 words. (10 marks )

Answer 1

1) Simply triple alpha process is a set of nuclear fusion reactions by which three He_4 nuclei are transformed into carbon.

2) In star the He nuclei occupied the core then the proton-proton chain reaction and the carbon nitrogen oxygen cycle will form.That the reaction will occur with He nuclei with hydrogen or other alpha particles. Heir these two particles are highly unstable and decay almost suddenly back into smaller. But the third one is fuses with a beryllium_8 nucleus before time to produce a stable carbon 12 nucleus. When a star run out of hydrogen to fuse in its core ,it begins to contract and heat up .If the central temperature is rise into 10^8K ,six times hotter than sun's core ,and the alpha particles can fuse fast enough to produce significant amounts of carbon.

(-0.0918 Me V)

+2Y (+7.367 MeV)

And the net energy releases of the process is7.275 MeV