NMR phase noise in bitter magnets.
J Magn Reson
; 148(2): 309-13, 2001 Feb.
Article
in En
| MEDLINE
| ID: mdl-11237636
ABSTRACT
We have studied the temporal instability of a high field resistive Bitter magnet through nuclear magnetic resonance (NMR). This instability leads to transverse spin decoherence in repeated and accumulated NMR experiments as is normally performed during signal averaging. We demonstrate this effect via Hahn echo and Carr--Purcell--Meiboom--Gill (CPMG) transverse relaxation experiments in a 23-T resistive magnet. Quantitative analysis was found to be consistent with separate measurements of the magnetic field frequency fluctuation spectrum, as well as with independent NMR experiments performed in a magnetic field with a controlled instability. Finally, the CPMG sequence with short pulse delays is shown to be successful in recovering the intrinsic spin--spin relaxation even in the presence of magnetic field temporal instability.
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Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Magn Reson
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2001
Document type:
Article
Affiliation country:
Estados Unidos