Differences between revisions 15 and 21 (spanning 6 versions)

Angular Sensing and Control (Oct, 2022)

Contents

Angular Sensing and Control (Oct, 2022)
Next Steps
Known issues

WFS ports

REFL (17, 45 MHz)

Optical layout
- https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=9238
- Same as O3GK
PZT1, PZT2, and REFL_WFS picomotors are available to center the beam on REFL_WFS1 and REFL_WFS2
Phasing is done by Kenta

POP (17, 45 MHz)

Optical layout
- https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=9623
- POP WFSs were newly installed after O3GK
POP-S and POP-P cameras are available
Phasing is done by Kenta

AS (17, 28 MHz)

Optical layout
- https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=9817
- Mostly same as O3GK
PZT1, PZT2, and AS_WFS picomotors are available to center the beam on AS_WFS1 and AS_WFS2
AS and OMC_TRANS CCDs are available
OMC_REFL CCD hasn't been connected
Phasing is done by Kenta in June

DC QPD ports

TMSX

There is only QPD2 (K1:TMS-X_IR_QPDA2_{PIT,YAW} ) on the TMSX in-air path. At a random Gouy phase position.
The beam was sent to the QPD2 when the X-arm is locked, but the X-arm alignment may have changed since then.
TMSX in-air table power budget
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22310
The in-air beam is extremely astigmatic
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22221
There are strong PIT-YAW coupling depending on the position of the beam
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22228
- Matteo-san's previous measurement did not show a strong coupling. It seems to depend on the position of the DC QPDs.
  - https://klog.icrr.u-tokyo.ac.jp/osl/?r=20263
- Is the TMSX in-air beam clipped in the TMS in-vac?
  - https://klog.icrr.u-tokyo.ac.jp/osl/?r=22762

TMSY

TMSY QPD1 and 2 are placed on the TMSY in-air table, with 90 degrees separated in Gouy phase
QPD1 is used to the beam position control feeding back to the BS (K1:ASC-DOF1_{P,Y} )
Beam profile
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22479
No PIT-YAW coupling
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22575

POP Forward

There are two DC QPDs on POP Forward, used for the initial alignment
- K1:ASC-POP_FORWARD_QPDA1_DC_{PIT,YAW}
- They can be found on sitemap > ASC overview > All DC QPDs

DC PDs

There are POP_P and POP_S DC PDs on POP.
- K1:LSC-POP_S{P}POL_DC
- Can anyone add them on an MEDM screen somewhere?

WFS Commissioning

WFS DC centering

General

Beam spots on the quadrant diodes must be centered (DC centering)
If the beam is off from the WFSs, use the picomotors first because the PZT ranges are not large
K1:ASC-DC{5,6,7}_{P,Y} are to be used for the WFS DC centering loops

REFL

Open the REFL shutter first for REFL WFS
K1:ASC-DC5_{P,Y} are used for the DC centering controls
- FM filters:
  - Gains: null (gain of 0) and Gain(UGF40)
  - LPF: p1 (pole at 1 Hz)
  - Integrator: p0:z1 (pole at 0 Hz, zero at 1 Hz) - turn this on after the LPF

POP

DC control loop not implemented yet

AS

DC control loop not implemented yet

Single Y arm

Sensing matrix
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22578
Input matrix
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22602
Output matrix
- K1:ASC-DSOFT_{P,Y} to IY
- K1:ASC-DHARD_{P,Y} to EY
Loops closed
- https://klog.icrr.u-tokyo.ac.jp/osl/?r=22671
Loops or noise haven't been characterized
No offsets were necessary on the sensors

Single X arm

PRMI

PRFPMI

DRFPMI

Next Steps

Infrastructure

Guardian implementation
- DC centering loops on REFL, POP, and AS
- Single Y, X arms, and PRMI guardstates for initial alignment
Add trigger for the main ASC switch (K1:ASC-WFS_GAIN) similarly to the IMC switch (K1:IMC-WFS_GAIN)

Simulation

Compare the measured sensing matrices against the simulation
- Koyama-kun's simulation GUI tool is available on the workstations
  - sitemap > Commissioning Top > finesse GUI

Integration

Implement single-Y, single-X, and PRMI controls for the initial alignment
- If the alignment is too off, first ADS then WFS control?
PRFPMI/DRFPMI angular controls
Noise budget

Known issues

TMSX PIT-YAW coupling
- The beam is slightly not centered in yaw on the second lens on the in-air table. Adjusting the beam position on the lens might fix the problem.

KAGRA/Subgroups/MIF/AngularSensing (last edited 2022-11-02 09:12:15 by KeikoKokeyama)

-  ⇤ ← Revision 15 as of 2022-10-26 11:26:46 → 
  Size: 4461
  Editor: KeikoKokeyama
  Comment:
+   ← Revision 21 as of 2022-11-02 09:12:15 → ⇥
  Size: 4685
  Editor: KeikoKokeyama
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 12:
+ * Phasing is done by Kenta
-Line 19:
+Line 20:
+ * Phasing is done by Kenta
-Line 28:
+Line 29:
+ * Phasing is done by Kenta in June
-Line 33:
+Line 35:
- * There is only QPD2 ({{{K1:TMS-X_IR_QPDA2_{PIT,YAW}}}}) on the TMSX in-air path. At a random Gouy phase position.
+ * There is only QPD2 ({{{K1:TMS-X_IR_QPDA2_{PIT,YAW} }}}) on the TMSX in-air path. At a random Gouy phase position.
-Line 43:
+Line 45:
+  * Is the TMSX in-air beam clipped in the TMS in-vac?
   * https://klog.icrr.u-tokyo.ac.jp/osl/?r=22762
-Line 47:
+Line 51:
- * QPD1 is used to the beam position control feeding back to the BS ({{{K1:ASC-DOF1_{P,Y}}}})
+ * QPD1 is used to the beam position control feeding back to the BS ({{{K1:ASC-DOF1_{P,Y} }}})
-Line 55:
+Line 59:
-  * {{{{K1:ASC-POP_FORWARD_QPDA1_DC_{PIT,YAW}}}}
+  * {{{K1:ASC-POP_FORWARD_QPDA1_DC_{PIT,YAW} }}}
-Line 70:
+Line 74:
- * {{{K1:ASC-DC{5,6,7}_{P,Y}}}} are to be used for the WFS DC centering loops
+ * {{{K1:ASC-DC{5,6,7}_{P,Y} }}} are to be used for the WFS DC centering loops
-Line 73:
+Line 77:
- * {{{K1:ASC-DC5_{P,Y}}}} are used for the DC centering controls
+ * {{{K1:ASC-DC5_{P,Y} }}} are used for the DC centering controls
-Line 89:
+Line 93:
+ * Output matrix
  * {{{K1:ASC-DSOFT_{P,Y} }}} to IY
  * {{{K1:ASC-DHARD_{P,Y} }}} to EY
-Line 91:
+Line 98:
-  * {{{K1:ASC-DSOFT_{P,Y}}}} to IY
  * {{{K1:ASC-DHARD_{P,Y}}}} to EY