Why Is Helium Used in Rockets?

choi

Nivedita Bhattacharjee, Explainer-What Is Helium and Why Is It Used in Rockets?  Reuters, Sept 7, 2024
https://www.usnews.com/news/worl ... -it-used-in-rockets
("Europe's new Ariane 6 rocket ditched the helium of its predecessor Ariane 5 for a novel pressurization system that converts a small portion of its primary liquid oxygen and hydrogen propellants to gas, which then pressurizes those fluids for the rocket engine")

Note:
(a) Ariane 6
https://en.wikipedia.org/wiki/Ariane_6
("This two-stage rocket utilizes liquid hydrogen [as propellant] and liquid oxygen pas oxider] (hydrolox) engines")
(b) Liquid hydrogen is a kind of cryogenic fuel.
https://en.wikipedia.org/wiki/Cryogenic_fuel