First attachment shows the MICH dark beam with no CO2 on ITMX, and second attachment shows MICH dark with 5W of CO2 on ITMX. We’d expect a nice bullseye if the CO2 and interferometer beam are well aligned. 

 

Third attachment shows the alignment sliders from the DRMI lock earlier today (or close to them, I might have touched up SR2 before I took a screenshot :$). In this alignment the single bounce beam off ITMX was clipped at the output port, see 4th attachment (not super surprising, the DRMI looked choppy and clipped also). Not wanting to be fooled by fringes, we decided to spend a bit of time on alignment. Craig walked the input alignment to get a slightly less clipped beam, see 5th and 6th attachments for sliders and AS port beam.

 

We didn’t bother to align MICH, with this new less-clipped input/bs/sr2 alignment, but rather jumped straight into the CO2 power chopping and pico’ing.

 

When we modulated the CO2X power with the IFO in single bounce we saw a corresponding modulation in the beam position on AS air, I pico’d the top periscope mirror (#3 in the F pico controllers) in positive x direction up to 8000 counts. the peak to peak modulation in the x and y directions on the camera seemed to get worse (see top 2 plots of 7th attachment). I went back down to -2000 on the pico, this seems to be the right direction. I'll pick this up again tomorrow after maintenance. I haven't tried the Y pico yet.

 

I’ve restored the alignment sliders to how they were before team TCS took over the interferometer today, left the pico at -2000 but powered down the controller, and turned off the CO2.