Device for maintaining a separation between two electric conductors

A device for maintaining the separation between two electric conductors, comprising:

• a dielectric spacer disposed between a first bearing zone and a second bearing zone which are mechanically and electrically continuous respectively with said two conductors;
• said first and second bearing zones constituting respectively parts of a first conductive surface and second conductive surface which are electrically continuous with said two conductors and which are adjacent to each other so that when a voltage is applied between these conductors a corresponding electric field is set up throughout the whole space between these two conductive surfaces;
• at least said first bearing zone being disposed at the bottom of a recess in said first conductive surface, so that this bearing zone is further away from said second conductive surface than the remainder of this first conductive surface, the edges of this recess being connected progressively with the remainder of this first conductive surface by a curved part to form an "embedding" of the spacer in this conductive surface, and said spacer having a high permittivity in the vicinity of said first bearing zone than it has further away from said first bearing zone.