The Study of a Suspended Optic
Abstract
The dynamics of a damped driven three-dimensional pendulum were studied to better understand the motion of LIGO (Laser Interferometer Gravitational-Wave Observatory) suspended optics. The optics are suspended by wires to the top of a cage and are actively controlled for precise positioning. We made a model suspended optic without a control loop. We drove the suspension point of the model at various frequencies and analyzed the resultant motion. The End-to-end program (LIGO numerical simulator) replicates various interferometer components. We simulated our experiment with E2e using the dimensions of the model and the experimentally determined natural frequencies and quality (Q) factors. The simulation reproduced our experimental data accurately. We observed energy transfer from the pendular (at 1.0 Hz) to the pitch (at 3.2 Hz) degree of freedom. The transfer function of the simulation shows that as the pendular Q factor is decreased the pitch peak increases, indicating that more of the pendular energy is transferred to the pitch motion. We are now working with the control loop engaged to simulate the actual LIGO suspended optics.
- Publication:
-
APS Southeastern Section Meeting Abstracts
- Pub Date:
- November 2003
- Bibcode:
- 2003APS..SES.EB005F