Cryogenic High Resolution Translation Unit (CTU)

摘要

The CTU (Cryogenics Translation Unit) is a low range (±1 mm) high resolution (<50 nm) translation unit to be used at cryogenic temperature (20K). The unit is a multipurpose device capable of fine closed loop positioning. This device can be used as active element in IR Instrumentation for compensating thermo-elastic deformation moving optical elements or sensors.CTU motion system is based in thin flexures deformation to assure repeatability and moves in closed loop mode by means of a fine linear actuator and a calibrated non contact capacitive sensor.This paper describes main design features, how cryogenic testing of main requirements was carried out (including methodologies used for calibration and submicron verification), tested performances, and main lesson learned during the development.