Re: capillary effect

[Bernard Cleyet <anngeorg@PACBELL.NET>]

How did you separate the film from the Hg, and what was the composition
of the film?

My thesis advisor (late '50's) used zapon on water, lifted the zapon
with wire loops, then used the film as a substrate to evaporate
selenium.  The final step was to dissolve the zapon after mounting the
film along with many more on a frame.  Result:  a pile of plates
polarizer for the IR.

bc

p.s. because  their specific activity is much greater?

Ludwik Kowalski wrote:

> On Sunday, Jun 1, 2003, Bernard Cleyet asked:
>
> > Was any care taken to ensure none of the uranium
> > went up your noses?
>
> Yes, hoods were available but not always used. I would
> be much more careful in working with Pu, Am or Cf.
>
> > Did you use Al foil or something thinner like zapon?
>
> To deposit uranium on a very thin dielectric film I used
> mercury below it. The mercury was on a paraffin plate,
> for example, in a 5 mm by 15 mm cavity carved to match
> the desired target shape. The potential difference was
> applied between the wire in the capillary tube and the
> wire in mercury. The film, initially ~1mm from mercury,
> would be attracted to it after the voltage was applied.
> The rate of success in separating thin films from mercury,
> after depositing uranium,  was something like 50%.
> Using mercury in this way was my own "invention."