How can I make a sodium anion (Na-)?

[ProjectFringe]

I tried to find out if the anion of sodium exists and I saw reference to it in some research papers. I realize that it would be uncommon because Na would most likely give up its electron rather than get another electron. So, does it really exist and if so how is it formed?

 

[TeethWhitener]

https://en.m.wikipedia.org/wiki/Alkalide

 

[ProjectFringe]

Thanks!