Cheryl, Kiwamu,

Related to 29808, 29793, WP6165

[Modified generic interface box is now installed]

We have replaced the generatic interface box with a modified box (S1103802) in the PSL booth today. The box was the one for reading out the EOM pick off (IMC-PWR_EOM) and the periscope power (IMC-PWR_IN). Their associated AC channels are now with a gain of 200 at high frequencies above 4 Hz as described in Daniel's log (29808).

[PDA55 is installed for monitoring the light before EOM]

In addition, we have newly installed a PDA55 in order to monitor intensity noise before the EOM. See the attached for the setup.

As shown in the picture, the PDA55 recieves light leaking to the first steering mirror after the PMC. According to a handheld power meter, the power level of thie light was about 1 mW. The PDA55 with the lowest gain setting gave us a DC voltage of 4 volts.

Currently IMC-PWR_EOM_AC and IMC-PWR_EOM_DC are connected to this new PDA55 and not to the actual EOM pick off.

[Some cleaning up]

There was an undumped reflection back form a lens (IO-MB_L2). We put a beam dump by the Faraday isolator of the ALS.

Also, some pictures are available in ResourseSpace https://ligoimages.mit.edu/?c=1712