Dimensions of the double slits in comparison to the electron?

[meatym]

what are the dimensions of the double slits in comparison to the electron?

what keeps the electron from decaying outside the environment of an atom long enough to run the experiment?

how are the electrons detected before and after the slits?

 

[berkeman]

what are the dimensions of the double slits in comparison to the electron?

Google is your friend...

what keeps the electron from decaying outside the environment of an atom long enough to run the experiment?

What do you mean by "decay"? Electrons are stable particles.