Low frequency three-dimensional E.S.R. imaging of large samples

Presents an apparatus for performing a true 3D electron spin resonance image reconstruction at low microwave frequency (1.3 GHz). The gradients G zz, Gzx, Gzy of the field Bz along the three perpendicular axes are directly controlled by a personal computer which is also used to store the converted signals and to compute the spin-density function from the projections. The mathematical technique used is a filtered projection obtained by means of the Fourier transforms, called 3D Fourier reconstruction. Examples of signal reconstruction on phantoms are given.