For the interferometer to function properly, our sensing beams must be properly centered on the various RF photodetectors we use for sensing the length degrees of freedom. Here is the method for doing this:

-1) Read ../Align a beam to a photodiode

0) Make sure the IFO has been recently aligned (by successfully running the "Align Full IFO" script from the C1IFO_CONFIGURE.adl screen).

1) Using the C1IFO_ALIGN.adl screen buttons (!), misalign the ITMs and ETMs. Make sure the PRM is aligned. Now put beam on the REFL diodes (REFL33, REFL166, and REFL_DD). Nothing needs to be locked to do this.

2) Align the ITMs and BS, and misalign everything else. Choose "Restore Michelson" from the C1IFO_CONFIGURE screen. Flip the sign of the MICH servo. Now put beam on the AS diodes (AS33 & ASDD). The Michelson needs to be locked to a bright fringe to do this. If the Michelson cannot be locked for some reason, misalign ITMY and put beam on the diodes.

3) Misalign the PRM, SRM, and ETMs. Align the ITMs and BS. Now put beam on the POX, POY, PODD, and SPOB photodetectors. Nothing needs to be locked to do this. To get light on POX and POY, ensure that the mechanical shutters are open (via the Mech_Shutters MEDM screen).