YamaT, Ushiba, Akutsu

This evening, we just analyzed things using the same data left in the ndscope by K. Tanaka (last night) to see what will be the results if using different peaks by ourselves by using cursors in the ndscope. Just for our quick check, we adapted 1.848 sec for the carrier and RF sideband (13.78 MHz); we learned that the ndscope could more zoom in, and the more detailed peak searching could be done.

Then, we saw the three carrier peaks are separating like 0.771 sec, 0.808 sec, and 0.744 sec, so these should correspond to 5.749 MHz, 6.025 MHz, 5.547 MHz as free-spectral range, and also correspond to 52.147 m, 49.758 m, and 54.03 m, respectively, while the designed absolute length is 53.3 m. Hmm, so large error!

In this data, it seems swept with MCe. The other options would be

• Sweep again with MCe but with lower speed.
• Sweep with thermal actuator to NPRO.
• Give up and use the method reported in 616.