 Sat Jun 25 20:23:59 2022, Koji, Update, IOO, WFS issues 
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I could run the WFS servo (6dofs) for more than 15min by flipping the sign for the MC2 Pit and WFS1 Yaw. (See attachments)
This may mean that the sign of the loops / the input matrix / the output matrix, as well as the sensors and actuators, have the problem. |
 Sat Jun 25 22:18:41 2022, Tomislav, Update, ASC, Simulation and reality comparisons
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In the attachment please find plots comparing controller output, local damping output, and error signals.
Input noises of the simulation are seismic noise, osem noise, input power fluctuations, sensing noises of WFSs and QPD, and air turbulence noise
for WFSs. There is also optical torque noise (radiation pressure effect). |
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Mon Jun 27 12:32:45 2022, yuta, Update, IOO, WFS issues fixed
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Mon Jun 27 13:25:50 2022, Cici, Update, General, Characterizing the Transfer Loop
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[Deeksha, Cici]
We first took data of a simple low pass filter, and attempted to perform a fit to both the magnitude and phase in order to find the Z of the
components. Once we felt confident in our ability to measure tranfer functions, we took data and plotted the transfer function of the existing control |
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Mon Jun 27 13:39:40 2022, Deeksha, Update, Electronics, Setting up the MokuLab
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[Cici, Deeksha]
On Friday Cici and I set up the Mokulab to take readings of our loop. The aim is to characterise the PZT, in a similar manner as before, by exciting
the circuit using our input noise (a swept sine) and recording the corresponding changes in the output. We used the MokuLab to observe the beat note |
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Mon Jun 27 18:54:27 2022, yuta, Update, LSC, Modulation depths measurement using Yarm cavity scan
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[Yehonathan, Yuta]
EDITED by YM on 22:11 June 27, 2022 to correct for a factor of two in the modulation index
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Tue Jun 28 09:03:58 2022, JC, Update, General, Organizing and Cleaning
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The plan for the tools in 40m
As of right now, there are 4 tool boxes. X-end, Y-end, Vertex, and the main tool box along the X-arm. The plan is the give each toolbox a set
of their own tools. The tools of X-end, Y-end, and Vertex toolboxes will be very similar containing the basic tools such as pliers, screwdrivers, allen |
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Tue Jun 28 14:24:23 2022, yuta, Update, BHD, BHD DC PD signals now also sent to c1lsc to circumvent IPC error
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[JC, Yuta]
To circumvent IPC error sending BHD DC PD signals from c1sus2 to c1lsc, DB9 cable from BHD DC PD box sent to c1sus2 is now split and sent also
to c1lsc. |
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Tue Jun 28 17:07:47 2022, Anchal, Update, Calibration, Added Beatnote channels in demodulation of c1cal
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I added today demodulation of C1:LSC-BEATX/Y_FINE_I/Q in the c1cal demodulation where different degrees of freedom can be dithered. For McCal (formerly
soCal), we'll dither the arm cavity for which we can use any of the DOFs (like DARM) to send the dither to ETMX/ETMY. Then with green laser locked
as well, we'll get the calibration signal from the beatnotes in the demodulaed channels. We can also read right after the mixing in c1cal model and |
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Tue Jun 28 18:19:09 2022, Tomislav, Update, Electronics, Electronics noise
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I measured electronics noise of WFSs and QPD (of the WFS/QPD, whitening, ADC...) by closing PSL and measuring the error signal. It was needed to put
the offset in C1:IOO-MC_TRANS_SUMFILT_OFFSET to 14000 cts (without offset the sum of quadrants would give zero, and 14000 cts is the value when the cavity
is locked). For WFS that are RF, if there is intensity noise at low frequencies, it is not affecting the measurement. |
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Tue Jun 28 22:27:11 2022, Yehonathan, Update, BHD, Measurement of input and output electronics noise
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{Yuta, Yehonathan}
For MICH noise budgeting we measure the input electronics noise which includes the AS55 RFPD, preamp, demod board, the whitening, and the AA
filters, and the ADC noises. To do so we simply close the laser shutter and take the spectrum of C1:LSC-AS55_I_ERR_DQ and C1:LSC-AS55_Q_ERR_DQ shown in |
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Tue Jun 28 23:10:34 2022, Yehonathan, Update, BHD, Measurement of AS55 demod board conversion factor
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{Yuta, Yehonathan}
We measured the AS55 demod board conversion from the amplitude of a 55MHz signal to a demodulated signal. We hooked the unused REFL55 LO into
the PD input port on the AS55 demod board. |
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