More than 4 hours lock!!
Thank you for your great work!
But, ..., Alaska earthquake may break the lock. Also, very large earquake occurred in Jamaica, maybe it will be difficult to lock the interferometer tonight.
Oh man...
Transfer function model is roughly consistent with measured one (fig2).
Assumptions
- ETMY actuator efficiency does not change so much from Dec.6
- ETMX actuator efficiency is close to ETMY one.
Current sensitivity is 10 times worse than the best sensitivity (Black curve).
So expected Inspiral Range is 4kpc. (I just only guess from Best one is 40kpc, did not compute form sensitivity.)
- Around 10Hz: YAW, LEN couple (fig3)?
- A few - several tens Herz: PIT, LEN couple (fig3)?
- Around 100Hz: MICH, DARM couple (fig4)?
- Above a few hundred Herz: ADC noise, Dark current noise?
Hi Takahiro,
Thank you for the rapid report on the sensitivity estimate.
As part of cross-check, could you give us the actual value for the sensing gain coefficient i.e., C(f=0Hz) for the power-recycled interferometer?
I am asking because the sensing gain should be now greater than that of the non-recycled case by a factor of sqrt{120}~10. My assumption is that the DARM signal should scale with sqrt(Parm) where Parm is the intracavity power in the arms. Plus, I silently assumed that the amount of the RF sidebands leaking into the dark port remianed identical with and without power-recycling.
Maybe MICH FF filter has to be updated for new configuration. I will do it if I can get time slot.
For short check, you can try turning off the MICH FF if the sensitivity changes or not.
C(f=0Hz) ~ 2e10 counts/Volt (from displacement to K1:LSC-AS_TRNORM_PDA1_RF17_Q_IN1)
We can change the pick-up point of error signal for the simple calibration.
In December, we used K1:LSC-DARM1_IN1 as the error signal.
So overall gain of LSC-AS_TRNORM_PDA1_RF17_Q was contained in the old optical gain.
I'm now checking the past calibration again.
Just remember that the OSTM is now attenuating the AS RF power by a factor of 100.
Just remember that the OSTM is now attenuating the AS RF power by a factor of 100.