Figure 12: An experimental arrangement used for investigation of He-Ne laser irradiation effect on the active gas mixture, obtained by action of nitric acid on copper. Designations: 1: He-Ne laser; 2: Syringe; 3: Nitric acid; 4: Reaction tube; 5: Tube made of copper, it is placed exactly below the syringe; 6: Place of the fan. The binary arrow shows the direction of air stream from the fan.