Re: how will neon react to a low powered laser in a vacume tube

According to conventional physics, the neon cannot give out any more light than 
it absorbs.  If the neon does absorb some light from the laser, it will simply 
re-radiate it, and to the eye this would probably appear as scattered light, as 
if the neon gas had a bit of smoke mixed in.

With this type of experiment, the best thing is to try it and see what happens.

Neon gas is supplied to neon signmakers in small glass globes.  If you can find 
a place to buy one of these (mail order?  or at a neon sign shop?), then you 
can simply shine a laser at the globe without any other preparation.