Isolation

The isolation table was designed to hold various equipment including a microscope above the magnet. When the pole cylinder is being turned, there are huge tangential forces exerted on the dynamic magnet base. Although this base is constructed of steel and probably weighs a ton, these forces are sufficiently large to shake the table! To overcome the effect of these vibrations on a microscope, an isolation table was designed to float above the dynamic magnet.

The table is an MDF frame with a construction foam interior for strength. On the top is a 1/4" Al plate with 1"x1" 1/4-20 square hole pattern for mounting hardware. The amount of metal used in the table construction was limited to reduce stray magnetic fields and eddy currents during dynamic operation. The screws used were stainless steel for their nonmagnetic/nonconducting properties.

The table sits on four air isolation chambers which in turn sit on four concrete columns. The isolation chambers provide an automatically leveled surface with variable height. They don not, however, have any other motion controls. This presented a problem as the travel of the table exceeded the dimensions of the sample area and endangered sensitive sample and probe equipment. To overcome this dilemma four steel brackets were attached to the dynamic magnet base table. A limit stop (long screw) was then added to the brackets to control the motion of the floating table.

Overall image of the rotating magnet and isolation table. In this picture you can see the cement bases on which the isolation columns sit; the motion limiting stops on the front and right sides; various instruments. Click Here for the SOLIDWORKS ASSEMBLY file for the floating table.

Front-side image of isolation table. The probe and microscope motion controls are visible.

Triple-axis motion control and the transverse Hall probe are used to characterize the static and dynamic fields.

A plexiglass plate is held ~2mm above the rotating cylinder. Its purpose is to keep stray objects from getting stuck between the cylinder and the box. Centered in this plate is a circular cup designed to keep probes and specimens away from the walls of the rotating cylinder. Click Here for the cup as a SOLIDWORKS PART, and Here for the SOLIDWORKS DRAWING.
Limit stops (seen above) were added to keep the probe/sample from hitting the walls of this protective cup.

Microscope mounted above sample cup. We also have the capabilites for video capture via our 7X zoom lens. Currently trying to upgrade the lens for greater zoom, but as you can see from the picture the working distance has to be significantly large (~50mm).