The main objective of this project is to carry out a laboratory-scale experimental investigation of the capabilities and potential advantages of carbon monoxide (CO) lasers, compared with carbon dioxide (CO2) lasers. Previous studies on CO2 lasers for decommissioning indicate that they can operate as elegant and flexible tools, but there are limitations with regard to cutting performance, and a need for articulated mirror-based beam delivery systems. The present project is motivated by: reported Japanese results indicating CO laser cutting performance significantly superior to that of CO2; and the potential for use of optical fibre beam delivery at the shorter wavelength (5 micro m cf 10.6 micro m).
The partner organizations (which are currently engaged in developing CO lasers in the power range up to approximately 1 kW) will carry out complementary investigations, using CO and CO2 beams, on steels, concrete and graphite concerning: the nature of the beam-workpiece interaction and how it differs at the 2 wavelengths; assessment of the respective cutting capabilities. It is expected that the work will: provide the sole European source of such information; enable quantification of possible technical and economic advantages of CO lasers for decommissioning; provide information on the parallel Japanese programme (where it is reported that CO lasers of > 20 kW are under development); make recommendations on a strategy regarding possible future use of CO lasers for decommissioning and commercial exploitation thereof.
The responsible partners for work on structural steel and graphite and for work on stainless steel and concrete will be AEA and DLR, respectively.
The main objective of this project is to carry out a laboratory scale experimental investigation of the capabilities and potential advantages of carbon monoxide lasers, compared with carbon dioxide lasers.
The responsible partners for work on structural steel and graphite and for work on stainless steel and concrete will be Atomic Energy Authority (AEA) and Deutsche Forschungsanstalt fuer Luft-und Raumfahrt eV (DLR) respectively. Detailed beam profiling of the AEA and DLR carbon monoxide lasers has been carried out (important because focused spot intensities govern strongly the beam workpiece interaction process). AEA has set up a temporary 20 m beam line to bring its carbon monoxide beam into the workstaion of its 5 kW carbon dioxide laser; the carbon dioxide laser beam is being used to create real world conditions of plasma and molten metal, the absorption of which at 5 um is being assessed using the carbon monoxide radiation as probe beam. The beam line is also being used to assess the influence of gaseous contaminants in the beam line on the transmitted laser power and beam quality, since this will yield information relevant to decommissioning applications. DLR has commenced studies of plasma ignition for carbon monoxide and carbon dioxide beams incident on stainless steel. The equipment for the measurment of beam reflectivity from solid and liquid (hot) metal surfaces has been constructed. The main diagnostic is an integrating Ulbricht sphere. Calculations have been carried out, resulting in a specification of a siliconm lens with small aberrations so that plasma ignition threshold is expected to be attainable with the DLR carbon monoxide laser.
1. Assessment of beam-workpiece interaction for CO laser, and comparisons with CO2 laser (All)
2. Assessment of CO laser cutting capabilities and comparisons with CO2 laser (All)
3. Final evaluation showing quantified differences in materials-processing capabilities of the 2 lasers, specific data on costs, secondary waste produced and radiological impact on workforce and working area (All).
Funding SchemeCSC - Cost-sharing contracts