Olaf Marzocchi wrote:
---Warning--- Obviously, the post is a big spoiler.
This is what I remember: the film is, probably, black and white, the
plot is: a scientist creates, probably with particle accelerators, a new
nuclide (atom species), a "living" one. It eats energy (usually fed with
particle accelerators), in the first part of the film not much, but then
more and more. I remember the scientist dies in an aeroplane, but I
don't remember how.
To feed the atom, the scientist had to turn off once all the lights of
the city, but then it was not enough anymore. The problem is that the
atom, instead of crying as a baby, emits magnetic forces, so it destroys
everything (there is iron in the buildings).
To kill it, the scientists go to New England, where there is a big
particle accelerator under a lake. They kill the atom by feeding it with
too much energy.
Well, I think that there are some wrong details there, but I am pretty
sure I know your film. I think they go to Canada, not New England.
That is because the footage used is from an old pre-war German film
called GOLD. The overalls the people wear do not look American, but
they figured Americans would believe scientists dress that way in
Canada.
But the film I think you are asking about is THE MAGNETIC MONSTER.
http://us.imdb.com/title/tt0046026/
You can look at the plot description there.