Online Log
The 4th. shift [1 Sep. 23:00 - 2 Sep. 7:00]
Core: S. Sato, Sub: N. Kanda
[Date 1 Sep. Time 23 : 00 #HDAQ 0 N. Kanda ]
100Hz - severl 100Hz, noise level seems bad.
[Date 1 Sep. Time 23 : 20 #HDAQ 2872 S. Sato ]
Ofset for L- loop was reduced to zero.
Still remain low frequency noise like ''gogogogo...'' in L- signal,
which can degrade spectrum in a few hyndreds Hz region.
[Date 1 Sep. Time 23 : 22 #HDAQ 2871 N. Kanda ]
Dr.Sato went underground floor to tune IF.
Noise spectrum around 70-400 Hz improved.
h(935Hz) 1.01*10^{-21}
Back to shift hut at HDAQ #2887.
We forgot to turn off OBS as off.
[Date 2 Sep. Time 00 : 50 #HDAQ 2954 N. Kanda ]
Noise spectrum is good as same as best.
But sometime burst like, broad floor up occures.
I feel that the gausiannity indicates this behavor well.
[Date 2 Sep. Time 01 : 10 #HDAQ 2972 N. Kanda ]
YAG indicater is RED (temperature = 40.5 degree)!
[Date 2 Sep. Time 01 : 05 #HDAQ 2965 N. Kanda ]
Dr. Sato went underground floor to tune alignments.
During this tuning, once laser's injection unlocked.
He back to shift hut at HDAQ #2973.
After tuning, noise level and contrast was improved.
(Contrast is better than 98%)
[Date 2 Sep. Time 01 : 10 #HDAQ 2973 S. Sato ]
Went down to IFO ASC maintenance, but IFO lost lock accidentally.
Injection lock was lost also.
IFO acquired lock and made some tuning
*Optimized arm and RM alignment
*Reduced ASC gain from 100 to 080
Result
*Burst noise is still remain
*Contrast was improved to 0.99-0.98
*Dark power fluctuation improved
[Date 2 Sep. Time 02 : 28 #HDAQ 3043 N. Kanda ]
Unlocked.
[Date 2 Sep. Time 2 : 38 #HDAQ 3052 N. Kanda ]
Obs.
Dr Sato back to shift hut.
[Date 2 Sep. Time 02 : 38 #HDAQ 3052 S. Sato ]
Dark power fluctuation seemed to make IFO lock lost
Injection lock was lost also.
[Date 2 Sep. Time 3 : 1 #HDAQ 3073 N. Kanda ]
Unlocked.
Seismic indicaters turn Red.
Earthquake.
[Date 2 Sep. Time 03 : 15 #HDAQ 3086 N. Kanda ]
Obs.
Dr.Sato back to the hut.
[Date 2 Sep. Time 03 : 15 #HDAQ 0 N. Kanda ]
Last Earthquake's info.
9/2 3:01
at Sagami-Bay, N 35.1, E 139.5, 100 m depth, M4.1
[Date 2 Sep. Time 3 : 26 #HDAQ 3095 N. Kanda ]
Since the noise floor level f>500 Hz, Dr.Sato went underground floor to check IFO.
He back to 3097.
[Date 2 Sep. Time 03 : 26 #HDAQ 3095 S. Sato ]
Missed to engage I-stab. loop after re-lock of IFO last time.
Engaged I-stab. loop and turned OBS on again.
[Date 2 Sep. Time 04 : 10 #HDAQ 3135 N. Kanda ]
Trans. EW was bad.
Dr. Sato went to underground floor.
Obs -> OFF
[Date 2 Sep. Time 4 : 16 #HDAQ 3141 N. Kanda ]
After alignment tuning,
Obs -> ON
[Date 2 Sep. Time 04 : 34 #HDAQ 3158 N. Kanda ]
Unlock
[Date 2 Sep. Time 07 : 01 #HDAQ event N. Kanda ]
Send
[Date 2 Sep. Time 07 : 01 #HDAQ 0 N. Kanda ]
Due to an increase of seismic motion, we cannot recover the
stable locking state.
Thus, we stop observation.