A nuclear fusion reactor is currently being built by the International Thermonuclear Experimental Reactor (ITER) in Cadarache, France. The process of fusing hydrogen isotopes into heavier elements releases a vast amount of heat which will be tapped to produce hot water and electricity. The vacuum core is filled with 150 million degree Celsius plasma and is confined using the electromagnetic forces. A core Charge Exchange Recombination Spectroscopy (cCXRS) will serve for visible light diagnostic and is consisted of seven mirrors (M1 to M7). The mirrors will reflect the visible light emitted by...