In-lab and On-sky Closed-loop Results of Adaptive Secondary Mirrors with TNO’s Hybrid Variable Reluctance Actuators
conference paper
We performed closed-loop lab testing of large-format deformable mirrors (DMs) with hybrid variable reluctance
actuators. TNO has been developing the hybrid variable reluctance actuators in support for a new generation
of adaptive secondary mirrors (ASMs), which aim to be more robust and reliable. Compared to the voice coil
actuators, this new actuator technology has a higher current to force efficiency, and thus can support DMs with
thicker facesheets. Before putting this new technology on-sky, it is necessary to understand how to control it
and how it behaves in closed-loop. We performed closed-loop tests with the Shack-Hartmann wavefront sensor
with three large-format deformable mirrors that use the TNO actuators: DM3, FLASH, and IRTF-ASM-1 ASM.
The wavefront sensor and the real-time control systems were developed for the NASA Infrared Telescope Facility
(IRTF) and the UH 2.2-meter telescope ASMs. We tested IRTF-ASM-1 on-sky and proved that it meets all of
our performance requirements. This work presents our lab setup for the experiments, the techniques we have
employed to drive these new ASMs, the results of our closed-loop lab tests for FLASH and IRTF-ASM-1, and
the on-sky closed-loop results of IRTF-ASM-1 ASM.
actuators. TNO has been developing the hybrid variable reluctance actuators in support for a new generation
of adaptive secondary mirrors (ASMs), which aim to be more robust and reliable. Compared to the voice coil
actuators, this new actuator technology has a higher current to force efficiency, and thus can support DMs with
thicker facesheets. Before putting this new technology on-sky, it is necessary to understand how to control it
and how it behaves in closed-loop. We performed closed-loop tests with the Shack-Hartmann wavefront sensor
with three large-format deformable mirrors that use the TNO actuators: DM3, FLASH, and IRTF-ASM-1 ASM.
The wavefront sensor and the real-time control systems were developed for the NASA Infrared Telescope Facility
(IRTF) and the UH 2.2-meter telescope ASMs. We tested IRTF-ASM-1 on-sky and proved that it meets all of
our performance requirements. This work presents our lab setup for the experiments, the techniques we have
employed to drive these new ASMs, the results of our closed-loop lab tests for FLASH and IRTF-ASM-1, and
the on-sky closed-loop results of IRTF-ASM-1 ASM.
TNO Identifier
1001164
Source title
SPIE conferentie SPIE Astronomical Telescopes & Instrumentation, Yokohama, Japan
Pages
1-15
Files
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