High homogeneity permanent magnet for diamond magnetometry

[Display omitted] •Summary of flux calculation for Halbach magnets.•Design and construction of a Halbach-magnet made from cylindrical magnets.•The magnet has to provide a field of 102.4 mT for diamond based magnetometry.•Diamond-based characterization with vectorial resolution of 7 μT and 0.020°.•The magnet will be part of a diamond widefield microscope. Halbach magnets are a source of homogeneous magnetic field in an enclosed volume while keeping stray fields at a minimum. Here, we present the design, construction, and characterization for a stack of two Halbach rings with 10 cm inner diameter providing a homogeneous (