The present invention is directed toward a magnetic resonance based
material detection system that includes a resonator probe which is highly
resonant, is cost effective and has a compact magnetic structure with a
low cost tuning mechanism and high quality factor (Q). The probe is
relatively immune to radio frequency interference and can be used in
close proximity to other resonator probes of similar design,
complementary sensing equipment, and electromagnetic shielding due to its
low external magnetic field. It is preferred that, if the magnetic
resonance based detection equipment is used with complementary sensing
equipment that uses x-rays, the portion of shielding that intersects the
x-ray beam is made of thin material of a conductive nature which retains
electromagnetic shielding properties while causing minimal attenuation to
x-rays. In one embodiment, the resonator probe is a rectangular-shaped
single turn toroid fabricated from copper sheets. The resonator probe
also has adjacent walls forming an inspection volume such that materials
can be passed through this inspection volume.
