Today we increased the size of the beam path on inner insulations for ACAV and RCAV, cleaned vacuum chambers' windows, and optics on the table.

We have suspected that scattering light dominates the noise  spectrum at low frequency, so we checked all possible scattering sources from the vacuum chamber.

We increased the size of the opening for the beam paths on ACAV/RCAV insulation caps.

We removed the cap by cutting the AL tape around, after that the caps are just placed back. We haven't taped them yet.

 ACAV's chamber windows are especially dirty, full of scratches, so we cleaned them with methanol.

We also found a reflection coming back from ACAV. The spot size is quite large, ~order of cm. The position is quite far from the incoming beam.

The source is still undetermined.

Optics on the setup are cleaned. They had dust, finger prints on them.

ACAV's periscope was readjusted, so that the beam hits near the center of the mirrors, not close to the edge of the mirror.

 RCAV temperature sensors are fixed and not noisy anymore.

Plots and pictures on the board outside the lab are updated.

As we are waiting for temperature to settle, we clean the lab.