
Be even better if he swapped out
the helium for XENON.
The Big Bang Theory Season 11, Episode 8

I'm telling you,
if XENON emits ultraviolet light...
The Big Bang Theory Season 4, Episode 4

And XENON has a bigger nucleus,
The Big Bang Theory Season 11, Episode 8

Well, if we run the XENON stream
through the cryocooler,
The Big Bang Theory Season 10, Episode 20

Yes, well, if we lived in a world where
slow-moving XENON produced light...
The Big Bang Theory Season 4, Episode 4