Non-contact linear slider for cryogenic environment

A non-contact linear slider based on stable superconducting magnetic levitation with a long permanent magnet as a slider and two fixed superconducting disks which define the slide way has been designed, built and tested. The slider can be moved stably along a stroke of +/- 11.5mm by supplying a low current in a coil located at the end of the stroke while the levitation remains stable providing a reliable mechanism for linear displacement in a cryogenic environment. The response is linear with a sensitivity of 52 +/- 2 mu m/mA for displacements lower than 6 mm. Run out, pitch, yaw and roll have been measured demonstrating an overall good performance. In all cases the measured hysteresis was lower than 250 mu m and the measured run out was also lower than 250 mu m both for Y and Z axis. Roll and yaw were always below 300 mu rad, that is one order of magnitude lower than the pitch (4500 mu rad). (C) 2011 Elsevier Ltd. All rights reserved.