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MIF (ITF Control)
yutaro.enomoto - 22:29 Friday 19 October 2018 (6624) Print this report
The First Locked Arm Cavity in KAGRA

[Kokeyama, Yokogawa, Sugimoto, and Enomoto; Fujii and Miyo for moving mass control]

Yeah!! It's locked!!!

The movie of TMSX_Gr camera is also attached.

================================================================

= What we did =
-- aligned ETMX so that the reflected green light comes back to POP reflection PD. When we found it, the oplev beam was slightly off in YAW.
-- went to X end and opened the GV at X end. Then good angle for ETMX slightly changed, mainly in YAW. Then we centered the QPD for ETMX TM tilt oplev.
-- came back to center area and opened the GVs (BS-ITMX, IXA-Xarm). We had to move PR3 a little bit.
-- aligned some optics on POP table using the reflection from ETMX; RF PD for Gr X, and lens and steering mirror for it.
-- aligned ITMX so that the reflection from ITMX overlaps with the incident light. We adjusted PIT first with the YAW slightly off, and then adjusted YAW by slightly exciting YAW. THEN...
-- found FLASH of X arm cavity, with both transmission PD and camera.
-- improved the alignment by looking at the camera. we mainly moved in PIT of ITMX and PR3.
-- found that the green lock loop was unintetionally closed, so opened the loop and then the flash got clearer.
-- then tried to close the green lock loop intentionally. After some trial and error, we achieved the lock of the X arm with the green laser!!!

= Note =
-- PLL for Gr X laser was important to achieve the lock; when it was not enageged, the flash was faster than when it is engaged. Thanks to the PLL, the green laser frequency is indeed stabilized.

Images attached to this report
Non-image files attached to this report
Comments to this report:
yuta.michimura - 22:39 Friday 19 October 2018 (6627) Print this report

You rock!!!

yutaro.enomoto - 22:52 Friday 19 October 2018 (6629) Print this report

7 minute lock

Images attached to this comment
yoshinori.fujii - 23:13 Friday 19 October 2018 (6630) Print this report

hoooooorrayy!!!!! You did it!

tomotada.akutsu - 0:13 Saturday 20 October 2018 (6632) Print this report

Omedetogazemasu!!

kiwamu.izumi - 5:01 Saturday 20 October 2018 (6633) Print this report

This is a historical moment!

shinji.miyoki - 7:15 Saturday 20 October 2018 (6634) Print this report
I missed the historical night shift orz.
chihiro.kozakai - 9:52 Saturday 20 October 2018 (6635) Print this report
Good job !!! Really nice !!
takafumi.ushiba - 10:03 Saturday 20 October 2018 (6636) Print this report

Great work!!

lucia.trozzo - 12:33 Saturday 20 October 2018 (6637) Print this report

Great Job guys!! 

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