Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: barrier penetration, evanescent waves



"For example, how often [do] two
protons and two neutrons happen to be bound into
an alpha particle inside a nucleus? Similar questions
can be asked for other clusters."

I think He-4 is doubly magic, therefore, they are likely to be the
particles that leave non-spherical nuclei (liquid drop?)

the below page does this at the kinder. level (without my high-falutin
phraseology)

http://www.colorado.edu/physics/2000/isotopes/alpha_decay.html

bc whose high energy career ended before 1964


Ludwik Kowalski wrote:

I see that JohnD changed the name of the thread. This
indicates that we are no longer addressing the issue of
how to introduce fission in an elementary physics course.
That is a different context.

My recollection is that in order to perform tunneling
calculations, either for alpha particles, or for other
nuclear chunks, one must know nuclear potential. This
used to be done semi-empirically, that is by using the
QM theory but choosing the nuclear well parameters
to match real experimental data.

It is true, as John keeps reminding us, that well
parameters chosen for alphas gave wrong lambda
for fission, and vice versa. But there were other
complications as well. For example, how often two
protons and two neutrons happen to be bound into
an alpha particle inside a nucleus? Similar questions
can be asked for other clusters.

That was the situation in late 1960's when I was
actively involved in fission physics research. Did
the situation really change since my "days of glory?"
Please share what you know.
Ludwik Kowalski