BS Actuator Design (including design for SRs and PRs)

Document #:

JGW-T1504450-v7

Document type:

T

Submitted by:

Yuta Michimura

Updated by:

Yuta Michimura

Document Created:

29 Oct 2015, 16:53

Contents Revised:

30 Nov 2015, 14:59

DB Info Revised:

16 Jun 2016, 15:28

Abstract:

Slides for the Special VIS+ISC meeting on BS magnets
http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/KAGRA/subgroup/ifo/MIF/Minutes20151104

Includes magnet choice for SRs and PRs

Files in Document:

• BSActuatorDesign.pdf (1.0 MB)

Topics:

• Activity:KAGRA
• Detector:Interferometer Sensing and Control
• Management:Collaboration meeting:KAGRA meeting
• Detector:Suspensions
• Detector:Circuits

Authors:

• Yuta Michimura

Notes and Changes:

== BS ==
* Design change summary
- Old design
-- BS TM: NdFeB 6mm dia, 3mm thick (0.0744 Am^2)
-- BS IM: NdFeB 10mm dia, 10mm thick (0.690 Am^2)

- New design
-- BS TM: SmCo 2mm dia, 3mm thick (http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/KAGRA/subgroup/ifo/MIF/Minutes20151104)
-- BS IM: SmCo NO CHANGE in size (see [kagra-seis 01218], as opposed to http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/KAGRA/Subgroups/VIS/VISMinutes20151113)

* Magnetic noise
- Old design (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=4459)
-- Uses measured magnetic field fluctuation when few equipments
installed in the tunnel
-- Magnetic noise from TM: 1/100 of the displacement noise requirement (at 10Hz)
-- Magnetic noise from IM: 1/1000 of the displacement noise requirement (at 10Hz)

- New design
-- Use x50 of the magnetic field fluctuation measurement (~ use Virgo measurement)
-- Magnetic noise from TM: ~1/18 of the displacement noise requirement (at 10Hz)
-- Magnetic noise from IM: ~1/20 of the displacement noise requirement (at 10Hz)
-> OK!

* Saturation check
- Old design (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=3453)
-- DAC output at lock acquisition for TM: 70 counts
-- DAC output during lock for IM: 3425 counts RMS

- New design
-- DAC output at lock acquisition for TM: ~630 counts
-- DAC output during lock for IM: ~3425 counts RMS
-> OK!


== SRs ==
* Design change summary
- Old design
-- SRs TM: NdFeB 6mm dia, 3mm thick (0.0744 Am^2)
-- SRs IM: NdFeB 10mm dia, 10mm thick (0.690 Am^2)

- New design
-- SRs TM: SmCo 2mm dia, 5mm thick (http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/KAGRA/subgroup/ifo/MIF/Minutes20151104)
-- SRs IM: SmCo NO CHANGE in size

* Magnetic noise
- Old design (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=4459)
-- Uses measured magnetic field fluctuation when few equipments
installed in the tunnel
-- Magnetic noise from TM: 1/30 of the displacement noise requirement (at 10Hz)
-- Magnetic noise from IM: 1/300 of the displacement noise requirement (at 10Hz)

- New design
-- Use x50 of the magnetic field fluctuation measurement (~ use Virgo measurement)
-- Magnetic noise from TM: ~1/3 of the displacement noise requirement (at 10Hz)
-- Magnetic noise from IM: ~1/6 of the displacement noise requirement (at 10Hz)
-> OK!

* Saturation check
- Old design (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=3453)
-- DAC output at lock acquisition for TM: 1500 counts
-- DAC output during lock for IM: 2641 counts RMS

- New design
-- DAC output at lock acquisition for TM: ~8300 counts
-- DAC output during lock for IM: ~2641 counts RMS
-> OK!


== PRs ==
* Design change summary
- Old design
-- PRs TM: NdFeB 6mm dia, 3mm thick (0.0744 Am^2)
-- PRs IM: NdFeB 10mm dia, 10mm thick (0.690 Am^2)

- New design
-- PRs TM: SmCo NO CHANGE in size (http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/KAGRA/subgroup/ifo/MIF/Minutes20151104)
-- PRs IM: SmCo NO CHANGE in size

* Magnetic noise
- Old design (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=4459)
-- Uses measured magnetic field fluctuation when few equipments
installed in the tunnel
-- Magnetic noise from TM: 1/1e4 of the displacement noise requirement (at 10Hz)
-- Magnetic noise from IM: 1/1e5 of the displacement noise requirement (at 10Hz)

- New design
-- Use x50 of the magnetic field fluctuation measurement (~ use Virgo measurement)
-- Magnetic noise from TM: ~1/200 of the displacement noise requirement (at 10Hz)
-- Magnetic noise from IM: ~1/2000 of the displacement noise requirement (at 10Hz)
-> OK!

* Saturation check
- Old design (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=3453)
-- DAC output at lock acquisition for TM: 1100000 counts
-- DAC output during lock for IM: 58883 counts RMS

- New design
-- DAC output at lock acquisition for TM: ~1100000 counts
-- DAC output during lock for IM: ~58883 counts RMS
-> CHANGE IN SUSPENSION OR COIL DRIVERS NEEDED!

Related Documents:

• JGW-T1100571: Recycler and Beam Splitter suspension structure
• JGW-D1503507: Low Power Coil Driver Board
• JGW-D1503503: High Power Coil Driver Board
• JGW-T1503239: OSEM Coil/Magnet/Flag Calculation
• JGW-T1503453: Actuator Noise Modeling Report
• JGW-T1504459: Magnetic noise calculation for BS (and ETM/ITM, PRM/SRM)
• JGW-D1504353: KAGRA OSEM assembly

Referenced by:

• JGW-E1605035: VIS Document and Drawing Tree (BS)