Arcsecond grating drive mechanism for operation at 4 K
Abstract
A grating drive mechanism that achieves arcsecond positional control at both room temperature and 4 K is described. The mechanism accommodates eight equally spaced facets on a 360° drum, with each facet having arcsecond control over an angular range of ±3°. The cryogenic portion consists of dry lubricated angular contact bearings, a d.c. brushless torque motor and a compact magnetic position sensor capable of < 1 arcsec r.m.s. resolution. Test results demonstrate angular repeatability of < 2 arcsec r.m.s. at 4 K and static power dissipation to the helium bath of < 100 μW.
- Publication:
-
Cryogenics
- Pub Date:
- December 1991
- DOI:
- 10.1016/0011-2275(91)90124-F
- Bibcode:
- 1991Cryo...31.1030D
- Keywords:
-
- Cryogenic Equipment;
- Gratings (Spectra);
- Infrared Spectrometers;
- Mechanical Drives;
- Space Infrared Telescope Facility;
- Ball Bearings;
- Control Systems Design;
- Cryogenic Temperature;
- Feedback Control;
- Torque Motors;
- Engineering (General)