runaway effect

runaway effect [′rən·ə‚wā i‚fekt]

(electronics)

The phenomenon whereby an increase in temperature causes an increase in a collector-terminal current in a transistor, which in turn results in a higher temperature and, ultimately, failure of the transistor; the effect limits the power output of the transistor.

(plasma physics)

The phenomenon whereby an electric current in a plasma produces heat through the Joule effect, and the resulting temperature increase results in an increase in conductivity and, thereby, an increase in current flow.