What the previous graph means.....
Peak designations:
1: 525.4 eV, (1s2s2)2S
2: 529.4 eV, (1s2s2p)4P
3: 539.9 eV, (1s2s2p)2P_
4: 544.9 eV, (1s2p2)4P
5: 551.0 eV, (1s2p2)2D
6: 561.1 eV, (1s2p2)2S