ok, let me simplify this...we will need a very small technique....while they say...(so to turn it very much difficult) to use a high pressure hydrogen vessel...

Electromagnetic Deflection in a Cathode Ray Tube, II - MagLab

Many people interact with cathode ray tubes for part, if not most, of the day without having a clue how they work. Here's the inside scoop.

NATIONALMAGLAB.ORG

https://nationalmaglab.org/education/magnet-academy/watch-play/interactive/electromagnetic-deflection-in-a-cathode-ray-tube-ii