Aso, Sugimoto, Tanaka

After the PD replacement (a log related to the replacement will be posted by Aso-san), we turned off and then connected the PDs with the Preamp circuits. Fig. 1 shows the dark noise spectra of DCPD_A(red) and DCPD_B(magenta), blue and green are the ones when we disconnected PDs and Preamps. As you can see, the noise levels are the same as the disconnected ones. It seems to be fine.

After that, we confirmed that PDs responced the flash and the amount of response from both PDs seems to be the same (fig.2).

Also we tried to lock OMC with the single bounced beam from ITMX according to Aso-san's procedure in klog31403 and succeeded it (fig.3). Therefore, the PDs seem to work well.