In fusion terminology, what does it imply by taking orientational average of the fusion cross section when one of the nuclei has some static deformation/orientation? How is this average taken?

Question

Braxton Gallagher · Accepted Answer

It means that you&#039;re accounting for the fact that the spins of the nuclei in the fusion interaction aren&#039;t (or are, perhaps) oriented in a particular way. For instance, consider the D-T fusion reaction          2    H  +              3    H  →              4    H  e  +  n  +  18    M  e  VThe deuteron           2    H (or d) has nuclear spin   ℏ, while the triton           3    H (or t) has nuclear spin       1    2    ℏ. But the final state,           4    H  e  +  n, has spin       1    2    ℏ. If the deuteron and the triton happen to interact with their spins aligned, the minimum angular momentum in the system is       3    2    ℏ, and the final state can&#039;t occur unless there&#039;s some orbital angular momentum to it. Most of the fusion will occur from collisions where the d and t spins happen to be anti-aligned with each other. Neglecting to account the times when the d and t are aligned parallel, and the fusion coefficient is much smaller, would overestimate the cross section by a factor of       2    3  , or thereabouts.

In fusion terminology, what does it imply by taking orientational

Answered question

Answer & Explanation

New Questions in Nuclear physics