Datensatz

Zusammenfassung

In NMR/MRI experiments at ultra low magnetic fields hyperpolarization techniques based on parahydrogen (pH2) could offer a simple way to circumvent the lack of the low equilibrium polarization of the sample. A chemical exchange reaction, taking place at B0 fields in the mT range, transfers polarized spins from pH2 via a transfer catalyst to the sample. This transfer reaction can enhance the sample polarization in B0 fields in the mT range by a factor of 105, offering sample polarizations comparable to polarization fields of 103-104 T. To investigate these newly developed techniques a SQUID based NMR/MRI system operating at a static magnetic field in the mT range is being developed. By using a SQUID for detecting the NMR Signal, the system can benefit from its very low intrinsic noise level. Additionally, SQUIDs are wide band detectors and can detect the signal of multiple kernels simultaneously. A design of an ultra low field MRI system and first results will be presented.