Nuclear Magnetic Resonance in Inhomogeneous Magnetic Fields

“…In weakly inhomogeneous fields, the CPMG echo envelope corresponds to the envelope of the free induction decay in a perfectly homogeneous field, and for a mono-exponential decay, the decay time constant would be the transverse relaxation time T 2 . In strongly inhomogeneous fields, the flip angle distribution gives rise to a superposition of the Hahn and stimulated echoes in the multi-echo train, and the signal decay is determined by effective transverse relaxation time T 2eff > T 2 [12].…”

Section: Methodsmentioning

confidence: 99%

Mobile NMR for Analysis of Polyethylene Pipes

et al. 2005

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NMR relaxometry is a suitable tool to determine the morphology of semi-crystalline polymers by its ability to discriminate between rigid, mostly crystalline and soft, usually amorphous material. The NMR-MOUSE • R (nuclear magnetic resonance mobile universal surface explorer) was explored in this work to supply morphological data of poly(ethylene) pipes nondestructively. PE-100 pipes were investigated in the new state, after squeezing them flat, and after annealing well below the glass temperature. Furthermore, the change in morphology induced by a pressure load from the inside and a point load from the outside was investigated as a function of depth, and the morphology change across a welding line was imaged. A shear-band was detected by destructive high-field NMR imaging in an area of severe deformation of a pipe, where an anomalous depths profile was observed by the NMR-MOUSE. These results demonstrate that the NMR-MOUSE is a suitable tool for non-destructive state assessment of polymer pipes on the basis of laboratory reference data.

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“…A systematic investigation of measurement methods and applications followed in the mid-1990s referring to the NMR-MOUSE (mobile universal surface explorer) as a handheld mobile sensor for unilateral NMR (7,8). It was demonstrated that the relaxation times T 1 , T 2 , and T 2e , can be measured by single and multi Hahn echo techniques as well as their solid-echo counterparts and also self-diffusion coefficients (9). In general, the relaxation times probe molecular mobility and residual dipolar couplings indicative of chain stiffness in elastomer materials.…”

Section: Introductionmentioning

confidence: 99%

Construction of a NMR‐MOUSE with short dead time

Anferova

Anferov

Adams

et al. 2002

Concepts Magn. Reson.

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ABSTRACT:The NMR-MOUSE is a nuclear magnetic resonance (NMR) sensor for unilateral NMR of materials suitable for process and quality control. Practical aspects of the sensor construction are described, in particular radiofrequency coil design and shielding procedures to reduce probe ringing. Dead times of less than 20 s can be achieved at frequencies in the vicinity of 20 MHz with permanent magnets within sensitive volumes up to 4 mm deep. First applications of the NMR-MOUSE to the analysis of historical books are reported.

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Nuclear Magnetic Resonance in Inhomogeneous Magnetic Fields

Cited by 123 publications

References 19 publications

Segmental Anisotropy in Strained Elastomers Detected with a Portable NMR Scanner

Segmental Anisotropy in Strained Elastomers Detected with a Portable NMR Scanner

Mobile NMR for Analysis of Polyethylene Pipes

Construction of a NMR‐MOUSE with short dead time

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