Abstract: An electro-magnet array for use in a sputtering apparatus. The array has a magnetisable core member extending substantially horizontally and having magnetisable outward projections arranged as at least two pairs of symmetrically opposed projections projecting outwardly from the core member. A pole member is associated with each projection and vertically displaced with respect thereto. A magnetisable coupler is arranged to couple each pole piece magnetically to its respective projection. A magnetising coil around each projection is arranged for producing a magnetic field aligned substantially with a horizontal axis of symmetry of its respective projection in dependence upon the direction of flow of electric current through the magnetising coil.

Abstract: A cryosurgical probe comprises a probe head operable to be cooled by the expansion of a refrigerant gas within the probe head; a probe handle having means for precooling the refrigerant gas; and a flexible catheter linking the probe handle and the probe head, the catheter defining a channel for carrying precooled refrigerant gas from the probe handle to the probe head.