Induction coil in high vacuum or in aggressive environment for an electromagnetic exciter, its construction process

This induction coil is made from an hollow core, with an external helicoidal groove and a copper coating inside and outside the core. The groove are filled with copper and the outer surface of the core is machined to obtain an helicoidal cooper conductor. The core is in a material allowing the induction coil to work in high vacuum (example: displacement of two differents targets in a proton beam). (A.B.). 4 refs., 2 figs