Magnetic Coupling to Suspension Magnets

Document #:

LIGO-G1200524-v2

Document type:

G - Presentations (eg Graphics)

Abstract:

We explore some of the possibilities for magnetic coupling to suspensions, using BSC-ISI Actuators affecting a QUAD Top Stage as an example.

Files in Document:

• G1200524-v2.pdf (file is not accessible)

Other Files:

• 2012-05-09_ISI2QUAD_MagneticCoupling.pdf (file is not accessible)
• G1200524-v2.ppt (file is not accessible)

Topics:

• Seismic Isolation
• Commissioning
• Suspensions
• Modelling

Authors:

• Jeffrey Kissel

Notes and Changes:

- (Slide 11) Changed description of ISI coil actuators now that I understand them better
- (Slide 16) Fixed units on field gradient requirement
- (Slide 21) Corrected, and made more explicit, the calculation of magnetic force, which changed / lowered the final answer (but only by a factor of a few, well within the order of magnitude estimates). Also split force into separate calculation for L and V, given different magnet arrangement.
- (Slide 18-19), Updated with corrected force, see above.
- Added / filled out conclusions.
- Added slides to part 3 for more detail
* (Slide 32) includes dimensions of ISI actuators
* (Slide 34) added reference to Robert Schofields work
- (Slide 36) Shows updated dipole field model, with less turns (518 -> 440) and smaller area (0.2x0.1 m^2 -> 9" x 1") more representative of the large actuator coil itself vs. the housing. (Measurement is unchanged).

Related Documents:

• LIGO-T050105: Advanced LIGO ITM/ETM SUS Magnets at Top Mass
• LIGO-T0900564: aLIGO Large Actuator Test Results from Qinetiq
• LIGO-T0900226: ISI actuator dynamic response identification
• LIGO-D0900360: aLIGO Systems, WBSC8-H2 Top Level Chamber Assembly
• LIGO-T050087: Magnetic Field Measurement
• LIGO-E050159: Interface Control Document (ICD): Seismic Isolation (SEI) – Suspension, UK Scope (SUS/UK)