NMR Mandhala Gradient by QuantumEnthusiast

Last crawled date: 3 years, 1 month ago

These are two parts of a gradient to be used with a Halbach Mandhala. The angle of the two gradient pieces relative to each other changes the gradient strength along the external homoegeneous field provided by the Mandhala.
This Thing has two distinct pieces that are designed to work together:
Top
8cm inner diameter, 10cm outer diameter
4 1/2" x 1/4" x 1" slots for N42 magnet (poles on tall, narrow sides)
Bottom
8cm inner diameter, 10cm outer diameter
4 1/2" x 1/4" x 1" slots for N42 magnet (poles on large faces)
NOTE: The N42 magnets for the two pieces are different. See the third photo for the directions of the magnetization for the different magnets in order to generate a quadrupolar field.
This design is based on an article by Peter Blümler ("Permanent Magnet System for MRI with Constant Gradient mechanically adjustable in Direction and Strength", Concepts in Magnetic Resonance Part B (Magnetic Resonance Engineering), No Vol. Number (2015), DOI 10.1002/cmr.b.21320). The third photo is part of Figure 5 in Blümler's article linked above.
This gradient is for use with a Halbach Mandhala, which you can find here: https://www.thingiverse.com/thing:3012509
To use this gradient, fit the bottom over the Mandhala. The top gradient should slide into the open spaces in the bottom. Turn the top gradient to change the strength of the gradient. The maximum gradient strength is observed when all the magnets are at 45-degree increments.
This Thing was designed by Jeremiah O'Mahony, Nick Torres, and Ken Zhu with guidance and good-natured mockery from Merideth Frey, PhD, in beautiful Yonkers, New York.