The Hall effect in an ionized gas (plasma) is significantly different from the Hall effect in solids (where the Hall parameter is always much less than unity). In a plasma, the Hall parameter can take any value. The Hall parameter, β, in a plasma is the ratio between the electron gyrofrequency, Ω e, and the electron-heavy particle collision frequency, ν : β β = Ω Ω e ν ν = e B m e ν ν where