We tried to optimize the control servo of IMC last week, and last night IMC has locked for more than 15 hours!

The attached plot is CH1:IMC-REFL-DC signal (0.4: unlocked, 0.2: locked), Ch2: AOM control signal(count), Ch3:suspension control signal(count).

*The drift of refl dc signal might because of misalginments of mirrors, and the short term osilattion is because of the room temerature fluctuation.
*The suspension range seems enough in the sense of the tidal motion.
*The mysterious noise seen during iKAGRA operation did not appear at all.

The optimization work of the IMC loop during last week will be posted soon.