KAGRA Logbook

[Ikeda, Nakagaki, YamaT]

This is a same work as klog#36572 for ITMX.
V1 IO chassis (S1807864) in IYV1 rack was replaced as V2 one (S2416129).
ADC/DAC noise check still remains, but replacing IO chassis itself was finished.

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As the same procedure in ITMX case, V2 IO chassis was launched at outside of IYV1 rack without connecting any circuit. This was a connection test of a new MTP fiber cable between the mine server room and the IYV room. At that time, the front-end was newly installed at U27-28 of C2 rack (but still named as K1IZ1) and K1IY1 at U18-19 of ICV rack was alive with the old configuration. Thanks to the fiber cabling and labeling work yesterday, it can be done smoothly and there was no issue on the connection test.

After the connection test, we stopped both K1IZ1 in C2 rack and K1IY1 in ICV rack, removed V1 IO chassis from U6-9 of IYV1 rack, installed V2 IO chassis to there, and plugged all cables to V2 IO chassis. (In the ITMX case, we connected V2 IO chassis at outside of the rack with circuits at first, but we concluded this procedure can be skipped in the yesterday's experience.) And then, V2 IO chassis was launched with the new K1IY1 in C2 rack which was renamed from K1IZ1. ITMY models were able to be launched without any timing and PCIe activation errors.

We haven't yet measured ADC/DAC noise with new hardware configuration. So replacement work isn't fully completed. On the other hand, noisy channel issue will be mitigated by replacing ADC/DAC board not IO chassis, so we can say replacing IO chassis itself was finished. We plan to measure the ADC/DAC noise in the new configuration on next Tuesday.

V1 IO chassis and the old K1IY1 front-end are still left in IYV room and ICV rack, respectively. After seeing weekend situation, we will return them back to Mozumi for the next replacement work.