Work

Feasibility of Surface Nuclear Magnetic Resonance With Absurdly Long Excitation Pulses

Year: 2024

Type: article

Abstract: The common understanding in surface nuclear magnetic resonance (NMR) is that the excitation pulse should be kept much shorter than the NMR relaxation times for an effective excitation. We present analytic, numerical, and experimental evidence demonstrating that this need not be so, and surface NMR signals can be retrieved even for absurdly long excitation pulses. We solve the Bloch equations in the limit of infinitely long excitation and use this result to demonstrate that a measurable magnetization can be obtained with long excitation pulses. We perform numerical simulations of the Bloch equations incorporating effects of relaxation‐during‐pulse, and our results suggest that long excitation pulses can be used to increase the depth of investigation, but that the spatial resolution of long pulse excitation is low. Data collected in Kompedal, Denmark using up to 3 s long excitation pulses provide experimental proof for the feasibility of long pulse surface NMR.

Source: Geophysical Research Letters

DOI: 10.1029/2024gl110826

Authors: Jakob Juul Larsen, M. Andy Kass, Denys Grombacher, Matthew P. Griffiths

Institutions: Aarhus University, Aarhus University Centre for Water Technology

Language: English

Topic: NMR spectroscopy and applications

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,900

Funders: Villum Fonden, Novo Nordisk, Novo Nordisk Fonden