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Specialty Chemistry Forums => Nuclear Chemistry and Radiochemistry Forum => Topic started by: Mitch on November 06, 2006, 09:41:37 PM

Title: Calculating the Bass Interaction Barrier
Post by: Mitch on November 06, 2006, 09:41:37 PM

So we talked about Interaction Barriers previously, but I didn't really mention how one would go about and calculate it. I won't go in details on how it is done, but I'll show you all the equations you'll need to calculate them yourself. The formula I'm using is called the Bass Interaction Formula and is taken mainly from Nuclear Physics A231 (1974) 45-46 (http://dx.doi.org/10.1016/0375-9474(74)90292-9).

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fblog.chemicalforums.com%2Fblog-bassbint.png&hash=ef8ed1c65465ac090682e0338dc3583c964ed919)

Where Z_t and Z_p are the number of protons in the target and projectile respectively. e2 is the familiar e² which equals 1.44 MeV*fm. d (range parameter) is 1.35fm and D_int (interaction distance) is 2.70fm, but these 2 values are the adjustable parameters. r₁₂ is given as (https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fblog.chemicalforums.com%2Fblog-bassr0.png&hash=59e019d806c26323997b8f5fc1b3ff8aa127e240), where A_p and A_t are the mass numbers of the projectile and target nucleus respectively, and where r₀ is 1.07fm. Finally x is the ratio of the coulomb force with the nuclear force and is calculated in the equation below.

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fblog.chemicalforums.com%2Fblog-bassx.png&hash=dcb767295f51cfd2e226aff40a56de9f5a186735)
Where as is the surface constant from the semi empirical mass equation and is taken as 17.0 MeV.

Bass also has an other equation named after him often referred to as the Bass Fusion Barrier Equation and we'll get to that in the next couple of days. Hope this is useful to someone out there.

Note1: Using a calculator, the calculated barriers seem to vary from 0.1MeV for light projectiles to 0.8MeV for Krypton. When I only use 3 significant figures in the calculation it did a much better job replicating his calculated barriers in the paper.

Mitch