Staging of theta pinches using laser-heat addition and magnetic compression

The thermodynamics of using laser heating in conjunction with magnetic compression in θ-pinch plasmas is discussed. It is shown that the minimum laser energy required to achieve a given plasma filling factor Λ (ratio of plasma to plasma tube area) is Elaser = Λ2/3Eplasma and that any filling factor up to Λ = 1 can be achieved. The proposed schemes have important implications for either increasing the performance of standard θ pinches or for replacing the single-turn θ-pinch coil by a multiturn solenoid.