Re: [Phys-l] Alpha decay intensity against distance

[Bernard Cleyet <bernardcleyet@redshift.com>]

This is where using e-chem. deposition is useful.

For a research project I deposited polonium on to silver foil from a  
radium D solution (Pb-210) -- this results in only self absorption  
and back scatter as the only complications.

For inverse square expts.  one may deposit Ag on to the head of a pin  
to obtain a "point" source and then do the electrolytic displacement.


Now I have a question for Dr. Edmiston.  In your experiment you use a  
dead time, for your corrections, of ~ three to four microseconds.   
[Unless I improperly calculated.]   These are remarkably short DTs,  
at least in my experience, where DTs are ~ tens to hundreds of  
microsecs.  How did you obtain your DT, and at what counting rate?   
This last is important as Lidwik knows from the thread which he  
initiated years ago, and was my first participation upon joining this  
list.

bc very puzzled.


On 2009, Sep 21, , at 10:39, ludwik kowalski wrote:

> 2) I would like to see the energy spectrum of alpha particles from a
> smoke detector source. Such sources are probably coated with thick
> layers of something (to prevent contamination and to maximize the
> ionization density). My guess is that the initial energy of 5.5 MeV is
> reduced to something like 4 or 3 MeV. Unfortunately, I do not have an
> energy calibration system.  What do you know about the energy spectrum
> of alphas from a smoke detector?