Method and system for processing a diamond

A method of processing a diamond to obtain vacancy-based defects and vacancy-based clusters, the method comprising the steps of:

• providing a polished artificial single-crystal diamond, with root-mean-square surface roughness of less than 1 nm with {001} faces, said artificial single-crystal diamond having a substitutional nitrogen concentration above or equal to 100 parts per million, wherein the surfaces of the diamond have been conditioned, in a first conditioning step, by boiling under reflux of a solution comprising nitric, sulphuric, and an oxidizing acid;
• irradiating the diamond with neutrons and/or electrons;
• conditioning, in a second conditioning step, the surfaces of the diamond at a temperature above or at least 100° C., under a constant gas flow with a pressure above or equal to atmosphere pressure;
• annealing the diamond,
• thereby obtaining a diamond with vacancy-based defects and vacancy-based clusters,
• wherein the second step of conditioning the surfaces of the diamond at a temperature above or at least 100° C., under a constant gas flow with a pressure above or equal to atmosphere pressure and annealing the diamond is performed in a closed cell having a gas inlet;
• a gas outlet;
• and one or more getter items configured to absorb impurities released from cell walls of the closed cell and/or present in a gas in the closed cell and/or released from a diamond placed in the closed cell during the second conditioning step of conditioning the surfaces of the diamond at a temperature above or at least 100° C., under a constant gas flow with a pressure above or equal to atmosphere pressure and/or annealing the diamond.