Re: radioactivity

[Jerry Lisantti <lisantti@PHYSICS.CENTENARY.EDU>]

There is indeed a relationship between the emitted alpha and the decay
constant lamba.  From Krane's Modern physics book:

lamba = v/(2R)*Exp[-2kL]

v = speed of alpha in the nucleus
R = radius of the nucleus
L = thickness of the barrier
k = Sqrt[(2mhbar)(u0-E)]
u0 = barrier height
E = energy of the particle

This assumes a rectangular energy barrier to tunnel through of length L
height u0.

Jerry Lisantti                              lisantti@physics.centenary.edu
Dept. of Physics and Biophysics            http://alpha.centenary.edu
Centenary College of Louisiana
Shreveport, LA  71134
318.869.5219

On Thu, 26 Oct 2000, Bernard G. Cleyet & Nancy Ann Seese wrote:

> Is there not a functional relationship between the decay constant and the energy
> of the emitted alpha?
>
> Are not all alphas mono-energetic?
>
> If the above is true, would not one be able to predict the decay constant
> knowing the dimensions of the energy barrier and the alpha energy?
>
> bc
>
>
> Leigh Palmer wrote:
>
> > The strong force is sufficiently strong to stabilize the uranium
> > nucleus against decay. However, if a couple of protons team up with
> > a couple of neutrons to form a helium nucleus inside the uranium
> > nucleus (in a picture popularized by George Gamow, author of the
> > Mr. Tompkins books) they would have enough energy to escape to
> > infinity. The strong force still poses a barrier to their escape,
> > but after many tries and billions of years, on average, the helium
> > nucleus escapes by quantum mechanical tunneling, the same mechanism
> > that allows a car to leave a garage without opening the door in the
> > Mr. Tompkins books.
> >
> > Leigh