Pinch (plasma physics)
(重定向自Plasma pinch effect)
![Lightning bolts illustrating electromagnetically pinched plasma filamentsA 1905 study of pinches, where electric lightning was used to create a Z-pinch inside a metal tube.[1]](/uploads/202502/03/Lightning_over_Oradea_Romania_32507.jpg)



A pinch is the compression of an electrically conducting filament by magnetic forces. The conductor is usually a plasma, but could also be a solid or liquid metal. Pinches were the first device used by mankind for controlled nuclear fusion.
The phenomenon may also be referred to as a Bennett pinch (after Willard Harrison Bennett), electromagnetic pinch, magnetic pinch, pinch effect or plasma pinch.