The gamma spectrum shown in Figure 2 is of the cobalt isotope , with two gamma rays with 1.17 MeV and 1.33 MeV respectively. ("See the decay scheme article for the decay scheme of cobalt-60.") The two gamma lines can be seen well-separated; the peak to the left of channel 200 most likely indicates a strong background radiation source that has not been subtracted. A backscatter peak can be seen at channel 150, similar to the second peak in Figure 1.