[Sakai, Yoshioka, Nakano]

The ISS experiment is going on at the Toyama Univ. The current status of the ISS is as follows:

• All of the transfer functions of each component such as the servo, the AOM, and the PD have been measured. The transfer functions seem healthy.
• The ISS loop was closed stably. The OLG has been measured and compared with the calculated one with the transfer functions of each component. Those are consistent.The UGF is around 20 kHz and the phase margin is more than 45 degrees. The attached figure is the calculated OLG. Unfortunately, we forgot to bring the data back from the lab and the phase delay and the gain is not the one we measured but just my imagination. We will show the measured plot tomorrow.
• The RIN was measured with the out-of-loop PD and the in-loop PD.  The spectrum shapes seemed the same as the previous measurement done by Furuhata-kun in Toyama Univ. The spectra will be shown in several days.
• The noise eater of the NPRO was turned on in the ISS experiment so far. We decided to turn it off since we turn the noise eater off in the PSL room. Actually, we saw the laser intensity oscillation when we just turn the room light on by the noise eater. It is so dangerous for us to turn it on during the observation.  Without the noise eater, the RIN got worth by a factor of 10. The spectra with/without the noise eater will also be shown soon.