[marcosdumay]

> What wavelengths am I protecting against?

Something around hundreds of meters. It's large enough that people don't treat it like a wave. Also, it's often semi-stationary, so you have to care to make your protection long-lived, and not only surge-based.

Coronal ejecta is formed by charged particles. The ones that can move only a few meters into the atmosphere. You don't have to catch those. There is also no high-frequency EM radiation.