I'm attaching the measurements of the QPD signals with excitations at 0.1Hz in ITMX pitch (1st attachment), ITMX yaw (2nd attachment), ETMX pitch (3rd), ETMX yaw (4th). As can be seen pitch and yaw are still very coupled on QPDA2. QPDA1 doesn't look as bad (I'm not sure it was bad before), and could be used for soft control, in theory we only need 1 QPD. I've also attached a photo of the new configuration.
The VIS ETMY guardian was throwing an error in the SAFE state:
2019-12-07T05:18:26.40263 VIS_ETMY W: Traceback (most recent call last):
2019-12-07T05:18:26.40265 File "/kagra/apps/guardian/lib/python2.7/site-packages/guardian/worker.py", line 461, in run
2019-12-07T05:18:26.40266 retval = statefunc()
2019-12-07T05:18:26.40266 File "/kagra/apps/guardian/lib/python2.7/site-packages/guardian/state.py", line 246, in __call__
2019-12-07T05:18:26.40267 main_return = self.func.__call__(state_obj, *args, **kwargs)
2019-12-07T05:18:26.40267 File "/opt/rtcds/userapps/release/vis/k1/guardian/TYPEA.py", line 143, in main
2019-12-07T05:18:26.40267 lib.all_off(self,optic)
2019-12-07T05:18:26.40268 File "/opt/rtcds/userapps/release/vis/common/guardian/typea_lib.py", line 331, in all_off
2019-12-07T05:18:26.40268 ip_tidal_off(GuardState,optic,60.0)
2019-12-07T05:18:26.40268 File "/opt/rtcds/userapps/release/vis/common/guardian/typea_lib.py", line 227, in ip_tidal_off
2019-12-07T05:18:26.40269 ezca['VIS-'+optic+'_IP_DAMP_%s_TRAMP'%DOF] = rampt
2019-12-07T05:18:26.40269 NameError: global name 'DOF' is not defined
The offending piece of code in the typea_lib.py was:
def ip_tidal_off(GuardState,optic,rampt):
ezca['VIS-'+optic+'_IP_DAMP_%s_TRAMP'%DOF] = rampt
if ezca['VIS-'+optic+'_IP_DAMP_%s_GAIN'%DOF] != 0.0:
ezca['VIS-'+optic+'_IP_DAMP_%s_GAIN'%DOF] = 0
As one can see "DOF" isn't defined. Also looking closer at the code, the ip_damp_off function already does what this function was trying to do. However I suspect that it's suppose to ramp down the VIS+optic+_IP_TIDAL_GAIN, so I've changed the function to:
def ip_tidal_off(GuardState,optic,rampt):
ezca['VIS-'+optic+'_IP_TIDAL_L_TRAMP'] = rampt
if ezca['VIS-'+optic+'_IP_TIDAL_L_GAIN'] != 0.0:
ezca['VIS-'+optic+'_IP_TIDAL_L_GAIN'] = 0
I've loaded all type A guardians.
Sheila, Adam,
We were curious about the DARM residual and how much of the linear range of the error signal it is using in a typical lock. I found a DQ'd channel that looks like the calibrated residual, K1:CAL-CS_PROC_DARM_RESIDUAL_DBL_DQ. The attached plots show the spectrum and rms of this residual from Tuesday night (see http://klog.icrr.u-tokyo.ac.jp/osl/?r=11927). The DARM sensitivity (GW channel) is also included.
As one can see the RMS of the residual is 4x10-11 m, which is approximately 1/4th of the peak of the error signal (which is at the cavity pole 16Hz). I realize I'm comparing metres to Hz, so here is the calculation.
vres = vlaser * Lres / Larm
vres = 3x1014Hz * 4x10-11m / 3x103m
vres = 4 Hz
This seems quite large, so we think we should boost the DARM loop to suppress this more.
Masayuki, Keiko, Adam, Sheila
We engaged the darm boost shown in the first attachment, and to recover some phase turned off the 1.48Hz lag filter in ETMY ISCINF, as well as the 60 Hz comb filter. Masayuki added a guarian state called DARM_BOOST which will engage this in the future.
Engaging this filter reduced the DARM residual RMS from 3e-11 meters to 2e-12 meters. The AS camera also became more stable, and the width of several lines in the DARM spectrum were reduced. The second attachment shows a couple of on/off tests, there are several things in the spectrum that are changing independent of the DARM boost but it does seem that the sidebands on the 60Hz lines are reduced, the 180Hz, 200 Hz and 300Hz peaks seem to go away. The broadband noise from 10-30Hz also seems lower with the boost on.
After we egaged the boost, Keiko and Masayuki turned on the MICH ASC and moved ETMY alignment, after this the AS camera really looks like a dark port. Adam recoreded a video of the much calmer AS port, I can't attach it to the alog but it is as users/adam.mullavey/ASportdarmboosted
High frequency sensitivity got better by factor of 5!!
Because of the contrast defect, the frequency noise, the intensity noise, or other common noise coupling was large. After tweaking of the alignment, the high frequency noise got much better.
Also, since the DARM error signal RMS got small, I could engaged the whitening stage of AS PD. It improved the sensivity factor of 2 more.
The BNS inspiral range is above 10 kpc now.
Thank you
Well, that might be consistent with that some ASC measurements shaking the test masses at lower freq region cause varying the sensitivity of the interferometer at higher freq region, as discussed in the afternoon meeting.
Now it is reaching order of 1e-17m/rtHz around 10-1kHz, it might be nice to consider couplings from RF noises (both phase and amplitude), as we still are using RF modulation to lock the FPMI. Putting my master thesis here (written in Japanese using an ancient interferometer) is very embarrassed for me, but hopefully it might be useful. (for example, Fig 6.10)
Thank you for your great effort! I will check the coherence soon.
I would like to leave the memo. After FPMI lock, BS Yaw started the oscillation with 0.18Hz(even I applied the sallignment).
By the way, looking at the spectrum of the BS oplev that Yokozawa-san attached, I wonder that the wind-shielding of the oplev setup would not be sufficient...?? or something wrong... The slope in the lower freq region seems too artificial??
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