how to to make the particles visible in the Particlesystem only when affected by light in a "night time scene"

Hello, I am trying to create a scene where it is a snowy night, I used Particalsystem to create the snow and a flashlight, the problem is I can’t get the snow to only be visible when it’s affected by the flashlight how can I make this possible?
thank you.

you probably need to assign a lit material for them