University of Toronto, Physics, Quantum Optics
Alan Stummer, Research Lab Technologist

Magnetic Null

NOTICE: This webpage and associated files is provided for reference only.  This is not a kit site!  It is a collection of my work here at the University of Toronto in the Physics department. If you are considering using any schematics, designs, or anything else from here then be warned that you had better know something of what you are about to do.  No design is guaranteed in any way, including workable schematic, board layout, HDL code, embedded software, user software, component selection, documentation, webpages, or anything.

All that said, if it says here it works then for me it worked. To make the project work may have involved undocumented additions, changes, deletions, tweaks, tunings, alterations, modifications, adjustments, waving of a wand while wearing a pointy black hat, appeals to electron deities and just plain doing whatever it takes to make the project work.

  • All files in the project.

  • Overview
    With Stefan Myrskog in Joseph's lab, started Jan'06.  In the BEC/DFG experiment, magnetic fields will ruin the MOT.  The largest culprit is the earth's magnetic field, about 0.3G.   Three large cage coils surrounding the experiment to null it out.  Usual methods to measure magnetic fields (hall effect, saturable coils, GMR) all have significant offset drifts.  By using a rotating sensor and measuring the rotational AC component only, any offset can be removed. A hall effect device is used, Honeywell type HMC1001.  With 12V wheatstone bridge drive, the output should be 38±11mV/G.

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