Low field NMR spans a range of diff

Low field NMR spans a range of different nuclear magnetic resonance (NMR) modalities, going from NMR conducted in permanent magnets, supporting magnetic fields of a few T, all the way down to zero field NMR, where the Earth's field is carefully shielded such that magnetic fields of nT are achieved where nuclear spin precession is close to zero. In a broad sense, "Low-field NMR" is the branch of nuclear magnetic resonance that is NOT conducted in superconducting high-field magnets. Low field NMR also includes Earth's field NMR where simply the Earth's field is exploited to cause nuclear spin-precession which is detected. With magnetic fields on the order of μT and below magnetometers such as SQUIDs or atomic magnetometers (among others) are used as detectors. "Normal" high field NMR relies on the detection of spin-precession with inductive detection with a simple coil. However, this detection modality becomes less sensitive as the magnetic field and the associated frequencies decrease. Hence the push toward alternative detection methods at very low fields.

ผลลัพธ์ (แอฟริกา) 1:

Lae veld KMR strek oor 'n verskeidenheid van verskillende kernmagnetieseresonansie (KMR) modaliteite, gaan van KMR wat in permanente magnete, ondersteun magnetiese velde van 'n paar T, al die pad af na nul veld KMR, waar die aarde se veld versigtig is beskerm sodat. magnetiese velde van nT bereik waar kern spin presessie is naby aan nul. In 'n breë sin, "Lae-veld KMR" is die tak van kernmagnetieseresonansie wat NIE gedoen word in 'n hoë-supergeleidende magnete veld. Lae veld KMR sluit ook die aarde se veld KMR waar net die aarde se veld uitgebuit om kern spin-presessie wat bespeur word veroorsaak. Met magnetiese velde op die einde van μT en onder magnetometers soos SQUID of atoom magnetometers (onder andere) word gebruik as detectors. "Normale" hoë veld KMR staatmaak op die opsporing van spin-presessie met induktiewe opsporing met 'n eenvoudige spoel. Maar hierdie opsporing modaliteit word minder sensitief as die magnetiese veld en die gepaardgaande afname frekwensies. Vandaar die druk in die rigting van alternatiewe opsporingsmetodes teen baie lae velde.