Re: [Phys-l] pinhole camera

[Ludwik Kowalski <kowalskil@mail.montclair.edu>]

On Apr 15, 2007, at 6:10 PM, John Denker wrote:

> On 04/15/2007 05:32 PM, Ludwik Kowalski wrote:
> > Here is an application in which a pinhole camera can be used today. (I
> > do not remember where I read about this, years ago.) Suppose you want
> > to know about distribution of X rays at the surface from which they  
> > are
> > emitted. A lead sheet with a pinhole, plus an X-ray film, is a
> > solution. The film will produce "the image" of the source. Yes, a lens
> > focusing X-rays, if it existed, would be desirable.
>
>
> Fresnel zone plates for focusing Xrays have been around for
> many years.
>
> For example:
>    S. J. Spector, C. J. Jacobsen, D. M. Tennant,
>    "Process optimization for production of sub-20 nm soft x-ray zone  
> plates"
>     
> http://xray1.physics.sunysb.edu/~micros/publications/papers/ 
> spector_jvstb_1997.pdf
>
> They are a royal pain to make, but they work a lot better than
> pinhole cameras.

Thanks for sharing. I was not aware that zone plates can be made for  
X-rays. Zones must be about two orders of magnitude smaller than for  
light.
_______________________________________________________
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/