A new method of diamond CVD with a closed gas circuit

A new closed gas circuit method for diamond chemical vapour deposition (CVD) has been investigated. On the basis of thermodynamic and kinetic considerations a carbon reactor has been designed which is able to remove undesired products of the CVD process and to replenish the necessary gaseous components, particularly methane and carbon monoxide. The limits of this gas regeneration method with respect to flow rates, pressure and temperature are reported and discussed.