| Peak labeled | Physical mechanism |
| a | Associative ionization (AI) |
| b | Penning Ionization (PI) |
| c | 1st Super elastic collision (electrons generated by AI) |
| d | 1st Super elastic collision (electrons generated by PI) |
| e | 2nd Super elastic collision (electrons generated via AI) |
| f | 2nd Super elastic collision (electrons generated via PI and PHI) |