Re: [Phys-l] pinhole camera

[Joseph Bellina <jbellina@saintmarys.edu>]

Aha,
The emission is probably isotropic so the pin hole camera works, but  
if the x-rays results from the reflection of an incident plane wave  
of x-rays...I was thinking of reflection rather than emission...then  
the reflected rays are generally not isotropic.

sorry for the confusion.

joe

Joseph J. Bellina, Jr. Ph.D.
Professor of Physics
Saint Mary's College
Notre Dame, IN 46556

On Apr 16, 2007, at 9:15 AM, Ludwik Kowalski wrote:

> On Apr 16, 2007, at 8:53 AM, Joseph Bellina wrote:
>
> > The problem with the pin hole X ray use is that it assumes that  
> > the X-
> > rays are reflected isotropically, when often they are not, so the pin
> > hole image is a convolution of the spacial array of the surface with
> > the intensity of the X-ray reflected in that direction.
>
> 1) Which reflection? In my mind it is only a matter of blocking versus
> unblocking of rays originating from different spots on the source.
> 2) A pin-hole can also be used to study a distribution of alpha and
> beta radioactivity on a flat source.
> _______________________________________________________
> Ludwik Kowalski, a retired physicist
> 5 Horizon Road, apt. 2702, Fort Lee, NJ, 07024, USA
> Also an amateur journalist at http://csam.montclair.edu/~kowalskil/cf/
>
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