1D shimming coil design and optimisation algorithm by Dr. Yujie Zhao University of St. Andrews, Scotland https://yujiephysics.wordpress.com/2023/11/09/nmr-maget-shimming-and-current-driver-design/
Highlights: In the project, our primary goal was not to develop a practical compensation system but to explore the mathematical methods, electronic and digital technologies required for future customized systems in our measurement installations.
Along this path, we have made significant progress:
➢Proposed a shimming coil architecture using a planar spiral coil system.
➢Tested Python algorithms for numerical optimization of functionals with a large number of variables.
➢Explored the Python symbolic calculus library SymPy, enabling complex calculations like derivatives.
➢Developed and tested a low-cost multi-channel PWM driver circuit with a current booster, facilitating the powering of numerous individual coils.
➢ Presented a scheme for testing electronic drivers using the Arduino microcontroller.
➢ Tested the MCP2221 USB-to-I2C adapter, allowing direct computer control of the multi-channel PWM drivers PCA9685 without the need for a microcontroller.
➢ Demonstrated effective heat management of electronic devices using voltage regulators and transistors.
➢ Identified potential manufacturing technologies for planar spiral coils.
➢ Successfully manufactured a working prototype of a four-channel electronic driver.
For more details, please read the report: "Design and optimisation of 1D shimming coils.pdf". The purpose of each project folder can be found in the report Appendix. You will have to tinker a little to install the Python libraries for MCP2221 and PCA9685. In the report we provide relevant links to the Adafruit website.
The combination of the idea of passive shim and 3D printing is discussed in the following paper: https://www.sciencedirect.com/science/article/abs/pii/S1090780724000867