| measured gain, P2L or Y2L | alpha | beam from center, mm | |
| (alpha * 42.2mm/alpha) * (-1, for pitch only) | |||
| mc1 p | -1.14 | -0.0544 | 2.30 |
| mc1 y | 1.882 | 0.0898 | 3.79 |
| mc2 p | -3.81 | -0.1818 | 7.67 |
| mc2 y | -0.4 | -0.0191 | -0.81 |
| mc3 p | -1.073 | -0.0512 | 2.16 |
| mc3 y | -2.83 | -0.1351 | -5.70 |
| 21-March-2017 | 17-May-2017 | diff, March to May | |
| mm | mm | mm | |
| mc1 p | 2.42 | 2.30 | -0.12 |
| mc1 y | 3.74 | 3.79 | 0.05 |
| mc2 p | 7.71 | 7.67 | -0.04 |
| mc2 y | -0.85 | -0.81 | 0.04 |
| mc3 p | 2.16 | 2.16 | 0 |
| mc3 y | -5.7 | -5.70 | 0 |
Virtually no change in IMC mirror beam spots before to after the vent.