Summary

The spot positions on the MC mirrors were measured with coil balance gains.
The estimated spot positions from the center of the MC1 and MC3 are as followings:

MC1H = +0.29 mm
MC1V = -0.43 mm
MC3H = +1.16 mm
MC3V = -0.68 mm

The cordinates are described in the figure

Method

As far as the cavity mirrors are aligned to the incident beam, spots on the MC1 and MC3 tell us the geometry of the incident beam.
Note that spot position on the MC2 is determined by the alignment of the MC1 and MC3, so it does not a big issue now.
The calibration between the coil balance and the spot position are described in the previous entry.

1. Lock the MC. Align it with MC2/MC3
2. Run A2L scripts. script/A2L/A2L_MC1 and so on.
   
   • The scripts run only on the solaris machines. They require "expect" in stalled some specific place which does not exist on the linux machines.
   • Excitation amplitude, excitation freq, readback channels were modified

Result

Beam powers
MC Trans: 0.18
MC Refl: 0.12-0.13

Alignment biases
MC1P 3.2531
MC1Y -1.0827
MC2P 3.4534
MC2Y -1.1747
MC3P -0.9054
MC3Y -3.1393

Coil balances
MC1H 1.02682
MC1V 0.959605
MC3H 0.936519
MC3V 1.10755

(subtract 1, then multiply 10.8mm => spot position.)