Confirming traditional spring reverb operation

[JKowalski]

Working on building a quick spring reverb setup, and wanted to confirm my thoughts on how they work commercially.



In the missing segment, there are the springs, which go through small cylindrical ferrous cores. These cores are magnets oriented radially, no? Meaning the poles are in line with the gap. I've read that SR units are usually torsional to reduce noise pickup - my guess is that the cylindrical cores are magnets oriented radially set up perpendicular to the field to generate torque?