Following the multitude of nuclear disasters over the past half century, increasing demands are being placed on new methods of radiation dosimetry. Currently, extracted teeth must be sent to the Helmholtz Institute in München where the enamel is removed before being analyzed using electron paramagnetic resonance spectrometry.
Electron paramagnetic resonance normally operates at X-Band (9.7 GHz) microwave frequencies and requires a magnetic field in the Tesla range, requiring large coils or even superconducting magnets. Consequently such equipment is large and anything but portable.
When using L-Band (1.2 GHz) microwaves, a magnetic field of as little as 40 mT can be used. This makes the use of simple NdBFe permanent magnets possible with the advantage of significant size reductions.
However, to facilitate this a homogeneous magnetic field must be generated. Using specially machined pole shoes it was possible to obtain a degree of field homogeneity adequate for EPR analysis. This project was financed and carried out in collaboration with the Helmholtz Institute in München.