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* We require to harmonize what it's been written already. | * We require to harmonize what it's been written already.Mark will be onto it sometime. |
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* Temperature stability. (Fabian.) | * Temperature stability of GAS filters. (Fabian.) * Long term stability of optic position measured by oplev. (Fabian.) |
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* '''For the two items above an alterntive approach would be to cite the prototype paper ponting out that the systems are very similar and similar results are expected.''' | |
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* Explain the selection of the blending filter in terms of the geophone noise belowthe resonance frequency. (Cite Takanori.) | * Explain the selection of the blending filter in terms of the geophone noise below the resonance frequency. (Cite Takanori.) |
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* klog entries: [[http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/KAGRA/Subgroups/VIS/TypeB/PaperTODOlist/klogs_md_ring|here]] | |
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* What was the criteria for choosing the ring position? | * What was the criteria for choosing the ring position, * Damping time? * Was the motion damped but not critically or overdamped? |
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* Produce a plot with the results of different tests. It doesn't have to beautiful but understanble. | * '''Explain the presence of residual motion at other frequencies that the oplev also senses and the damper ring does not damp. Remember Brazil!''' * Produce a plot with the results of different tests. It doesn't have to beautiful but understandable. |
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= TO DO list for Hirata-san = | = TO DO list for Hirata-san: 3D-CAD views = The task requires reading and provide beautiful 3D-CAD views according to the content. * Check what Fabian has produced in the past [[https://1drv.ms/p/s!AoQaV1tdsEcUgc0KPnQviZsbvLypkA?e=nThxd2|here]]. Some of it may be useful. Decide which ones are suitable if any. * I have been using PNG format. * Whole chain with chamber. * Whole chain without chamber. (In the figure we currently have, which was produced by Fabian, the optical table is not in the right place!) * IP. * GAS filter. * IM/IRM. * Optic/RM. |
Describe KAGRA/Subgroups/VIS/TypeB/PaperTODOlist here.
Contents
To Do list for the Type-B paper
Author list (Fabian)
- Paste the appropriate KAGRA's full author list.
- Check Panwei's status and write him in case he's not a collaborator. We're reporting his OSEM sensitivity measurements.
- Write to Rikako. We're reporting her damper ring measurements.
Introduction
The mechanical system
The text was mostly done by Mark.
- We require to harmonize what it's been written already.Mark will be onto it sometime.
- Decent 3D-CAD figures are required. (Hirata-san.)
Sensors and actuators for control
OSEMs
Brief description of the anatomy of the OSEMs.
- Produce a nicer figure. (Fabian.)
Typical OSEM sensitivity measured when locking the target. These are Panwei's measurements.
Typical measuring range according to all the units used in BS, SR2, SR3 and SRM.
- Typical calibration value. (Fabian, klog 4189.)
- Produce a nicer plot (Fabian).
- Write the figure caption (Fabian).
- Write a couple of sentences about the coil-magnet actuator and cite Mark’s document and Michimura-san’s paper. (Mark.)
LVDTs
Optical lever
Brief description of the oplev.
Brief description of diagonalization procedure.
Where the displacement calibration comes from: relativeposition of components measured with ruler, dimensions given by the 3D-CAD, QPD displacement calibration and comparison with IP displacement.
Typical extent of coupling after diagonalization.
Typical measuring range.
- Write the diameter of the beam determines the linear range of the QPD as a beam displacement sensor. (Fabian.)
- Point out that the oplev is expected to be limited by the seismic motion. (Fabian.)
- Say it is not easy to measure directly the oplev sensitivity but it is possible to set an upper limit to the optic rms displacement and velocities. (Fabian.)
Inertial sensors
Brief description of what a geophone is.
Brief explanation of the calculation of the noise determining the sensitivity.
- Say that below the resonant frequency the noise goes as f^-{3.5} and explain the reason. (Fabian.)
- Produce a nicer plot. (Fabian.)
Briefly say how they were calibrated against a calibrated seismometer.
Say the noise was measured using three channel correlation analysis.
Say we are in the process of finding out the reson of discrepancy betwwen the predicted and measured sensitivity.
Rigid body model of suspension (Mark)
Write relatively brief description.
Control and performance
Control topology
Copy and modify whatever Terrence wrote already. (Fabian.)
Performance at low frequencies (Fabian)
- Magnetic damper ring. Include Rikako and Enzo’s measurements. (Fabian and Enzo.)
- Temperature stability of GAS filters. (Fabian.)
- Long term stability of optic position measured by oplev. (Fabian.)
- Measured quality factors of resonances with control system on and off. (To be mesured by Fabian after the 1st wave of the pandemic.)
- Damping time of resonant motion with the control system on and off. (To be mesured by Fabian after the 1st wave of the pandemic.)
For the two items above an alterntive approach would be to cite the prototype paper ponting out that the systems are very similar and similar results are expected.
Optic residual displacement and velocity rms measured with the oplev in a day with good weather; show coherence with seismometer on ground.
- Describe the control system used:
- –Say that due to time constrains and to unidentified noise sources it wasn’tpossible to implement inertial damping.
- –IP: LVDT position control and damping.
- –F0: LVDT position control and damping.
- –F1: LVDT position control and damping.
- –BF: LVDT position control and damping.
- –IM OSEMs: position control from oplev and damping from the OSEMs readout.
- –Oplev: position control acting on IM and damping o the mirror.
Performancer at high frequencies (Fabian)
This is a mixture of things to write and a TO DO list for Fabian. Not everything has to be in the paper.
In the case of the IPLVDTs calculate the displacement sensitivity in L,T and Y. (For the calculation not for the paper.)
In the case of the IP geophones calculate the displacement sensitivity in L, T and Y. (For the calculation not for the paper.)
- In the case of the IM OSEMs calculate the displacement sensitivity in L, T, V, R, P and Y. (For the calculation not for the paper.)
- Inertial damping and reduction of the effect of the microseismic peak.
- Explain the selection of the blending filter in terms of the geophone noise below the resonance frequency. (Cite Takanori.)
- Choose the blending frequency according to the following:
- Frequency at which the geophone noise equals the LVDT noise.
- Figure of merit: reduction of the microseismic motion induced on the mirror with the inertial damping.
- Figure of merit: The geophone injected noise at low frequencies should not be too large.
- Describe the control system used in the calculation:
- IP: LVDT position control and inertial damping.
- F0: LVDT rolled-off position control and damping of the whole vertical chain.
- F1: LVDT rolled-off position control.
- BF: LVDT rolled-off position control.
- IM OSEMs: off.
- Oplev: off.
- Check the contribution of the wavefront sensor in Takanori’s thesis.
- Calculated expected performance within IFO observation band including injectedcontrol noise and comparison with requirement. (Fabian.)
TO DO list for Enzo: damper ring performance
Not all the items are to appear in the paper. Some of them are for general information. In order to avoid loading too much work on Enzo, Fabian will write the text fr the paper with the information provided by him.
- Compile a list of useful klog entries about the damper ring.
klog entries: here
- Where's Rikako's presentation?
- Did Rikako write a report?
- Which mode does the damper ring aims to damp?
- What was the criteria for choosing the ring position,
- Damping time?
- Was the motion damped but not critically or overdamped?
- Describe in an itemized way the procedure for finding the suitable position of the damper ring. For example:
- We moved the damper ring to ZZZ position moving KKK components.
- At a position XXX we excited the YYY mode usng VVV actuators and measured the damping time with the oplev.
- We used a least-square fit to data or any other fancier method.
Explain the presence of residual motion at other frequencies that the oplev also senses and the damper ring does not damp. Remember Brazil!
- Produce a plot with the results of different tests. It doesn't have to beautiful but understandable.
- Provide raw data for a beautiful plot.
TO DO list for Hirata-san: 3D-CAD views
The task requires reading and provide beautiful 3D-CAD views according to the content.
Check what Fabian has produced in the past here. Some of it may be useful. Decide which ones are suitable if any.
- I have been using PNG format.
- Whole chain with chamber.
- Whole chain without chamber. (In the figure we currently have, which was produced by Fabian, the optical table is not in the right place!)
- IP.
- GAS filter.
- IM/IRM.
- Optic/RM.