Abstract: The measuring detector is constituted by the resistance of a given volume of doped semiconductor, there being formed on one face of a semiconducting monocrystal a surface region having a well-determined thickness and a well-determined concentration of doping ions and two electrical contacts at the extremities of said region.The doped surface region is obtained by ion implantation and there is formed on the second face of the monocrystal a metallic coating which has good thermal conductivity and is in good thermal contact with said second face.The detector is primarily applicable to thermometric measurements at very low temperatures below 1.degree. K.

Abstract: Implantation of particles and especially ions is carried out by directing a particle beam onto a target and sweeping the beam in two directions at right angles. The target is subjected to a double movement of rotation about two axes which are substantially parallel to the direction of the particle beam. All the points of the target thus describe an epicycloid and are subjected to implantation by the particle beam.