Considerations are presented on the wall protection of inertial confinement fusion reactors by means of a falling cylindrical curtain of liquid metal that is intermittently contricted into a string of closed envelopes by the action of a series of cusped fields generated around the falling liquid cylinder. The formation of a liquid metal envelope in free space is discussed and the motion of the liquid curtain during constriction is numerically analyzed under the assumption of infinitesimally small curtain thickness and infinitely large conductivity. The single-turn cusp-field driver coils are assumed to have a circular cross section. The calculations indicate that the energy required for the driving field is quite small compared with the thermonuclear energy produced per pulse, and that an adequate electromagnetic force is generated by the coils for a 1 m radius cylindrical curtain of liquid lithium if it is constricted into closed envelopes within an interval of 30 ms.