A locking clamp that enables high thermal and vibrational stability for kinematic optical mounts

TL;DR

This paper presents a novel locking clamp designed to significantly improve the thermal stability of kinematic optical mounts, enabling precise mirror positioning in high-precision astronomical instruments.

Contribution

The authors developed a locking clamp that enhances thermal stability of optical mounts by approximately ten times, addressing a gap in commercial zero-drift mounts for 0-20°C temperature range.

Findings

Thermal stability increased by ~10x with the new clamp.

Clamp maintains microradian mirror positioning accuracy.

Provisional patent filed for the mount design.

Abstract

One of the main pursuits of the MagAO-X project is imaging planets around nearby stars with the direct detection method utilizing an extreme AO system and a coronagraph and a large telescope. The MagAO-X astronomical coronagraph will be implemented on the 6.5 meter Clay Magellan Telescope in Chile. The 22 mirrors in the system require a high level of mirror stability. Our goal is less than 1 microradian drift in tilt per mirror per one degree Celsius change in temperature. There are no commercial 2inch kinematic optical mounts that are truly "zero-drift" from 0-20C. Our solution to this problem was to develop a locking clamp to keep our optics stable and fulfill our specifications. After performing temperature variation and thermal shock testing, we conclude that this novel locking clamp significantly increases the thermal stability of stainless steel mounts by ~10x but still allows accurate microradian positioning of a mirror. A provisional patent (#62/632,544) has been obtained for this mount.