Stuttgart 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
A: Fachverband Atomphysik
A 2: Atomic systems in external fields I
A 2.7: Vortrag
Montag, 12. März 2012, 12:00–12:15, V57.05
3He magnetometer for ultra-sensitive measurements of high magnetic fields — •Anna Nikiel1,2, Peter Blümler1, Werner Heil1, Sergei Karpuk1, Ernst Otten1, Andrea Amar3, Kerstin Münnemann3, and Maxim Terekhov4 — 1Institut für Physik, Johannes Gutenberg-Universität Mainz — 2GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt — 3MPI für Polymerforschung, Mainz — 4Universitätmedizin Mainz
NMR methods are usually used as on-line monitor to measure magnetic fields > 1 Tesla and to trace possible fluctuations. In cases where a very high sensitivity is required an excellent signal to noise ratio (SNR) as well as a long transverse relaxation time T2* of the free induction decay (FID) following an NMR excitation is demanded. For example, in Penning trap mass spectroscopy the envisaged resolution of 1 part in 1011 or better, requires keeping the magnetic field and its time dependence under control at the same level.
Our approach for an ultra-sensitive measurement of high magnetic fields is to use a gaseous, nuclear spin-polarized 3He spin sample which can reach transverse relaxation times of several seconds, that is far beyond the typical millisecond FID time of a thermally polarized water sample.
We will report on first results obtained in the 1.5 Tesla field of a commercial medical NMR scanner. The 3He gas is spin-polarized in-situ using a new, non-standard variant of Metastability Exchange Optical Pumping (MEOP).