There are two verbs which sound very similar but have very different meanings.
To damp means to diminish the activity of something, or to reduce the oscillations of something.
To dampen means to make something slightly wet.
So when Geordi LaForge uses a dampening field to counteract the alien probe's tractor beam (or whatever), he's actually getting it slightly wet. What LeForge really should use is a damping field.
(And yes, I know that the dictionary cross-lists both definitions for both words. To my great consternation, this misuse is now so common it has become acceptable usage.)