This procedure is for full alignment of the SPL big compressor. A camera for viewing the IR beam reflection on the iris is recommend.
Step-by-step guide
- send the beam to grating 1 (G1): align incident beam through iris 1 &2
- normalize G1: turn G1 to retro beam back to iris1. Record the reading on G1-R (5.5º)
- send the beam to grating 2 (G2): turn G1 by 17º so that the beam is reflected onto the center of G2. Record the reading on G1-R (-11.5º = 5.5º - 17º )
- normalize grating 2 (G2): turn G2 to retro back to the iris1. Record the reading on G2-R(-33.3º)
- zero G1 & G2: turn both G1 and G2 to zero angles (5.5º & -33.3º+34º)
- working angles: turn both G1 and G2 to 1st order angles (5.5º - 56.1º =-50.6º & 0.7º-56.1º = 55.4º).
- rotate the roof mirror so that the "plumb bob" shadows overlap to each other
- adjust the linear stage (G2 T)to get the shortest pulse on SSA
Related articles