Project Details
Projekt
Follow-up proposal 2nd phase: Mobile Magnetic Ressonance Sensor utilizing a superconductive coil for prepolarisation in the near subsurface (MORE SPIN)
Subject Area
Geophysics
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 456346847
The aim of the MoreSpin project is the development of a highly mobile NMR sensor to detect lateral and vertical changes in the soil moisture content down to about 2 m depth. Soil moisture is important for numerous processes. As soil is the interface between the atmosphere and the subsurface it is relevant for fluid and mass transport processes. However, up to now, there are no adequate methods that can directly map the soil moisture content at all demanded time and spatial scales. Either the methods are direct but cannot be used on a large scale or they can be used on the large scale such as common geophysical methods but are indirect and therefore suffer from ambiguities. As a non-destructive direct method nuclear magnetic resonance (NMR) and its application from the surface of the Earth (SNMR) has gained increasing interest in the geophysical community to target hydrological questions. Unfortunately, conventional SNMR is not capable to deliver soil parameters for the very near surface (dm). This is due to the insufficiently low sensitivity at that particular depth range and the high expenditure of time that is needed to map large (km) areas. Based on promising theoretical concepts the MoreSpin project started to develop a new NMR-based sensor aiming to provide the necessary fast measurement progress and depth sensitivity. In a first phase, the feasibility of the concept, prepolarization using a superconducting coil together with adiabatic pulses and small point-like receivers, has been positively evaluated numerically, in the laboratory, and by preliminary field experiments. Thus, a full-functional new demonstrator, to be built in the second phase, promises to access the soil moisture distribution at a large scale and at selected depths (e.g., top soil, root zone, subsoil). It has the potential to become a groundbreaking tool to obtain information on mass transport (in connection with permafrost or climate change modelling), groundwater recharge, soil protection or even precision agriculture. In the second phase, a full-functional demonstrator will be built and applied in a soil physics project where the results are compared and evaluated against established and new methods.
DFG Programme
New Instrumentation for Research
