title: Numerical study of ultra-low field nuclear magnetic resonance relaxometry utilizing a single axis magnetometer for signal detection.
abstract: OBJECTIVE
  This paper investigates optimal placement of a localized single-axis magnetometer for ultralow field (ULF) relaxometry in view of various sample shapes and sizes.
  
  
  METHODS
  The authors used finite element method for the numerical analysis to determine the sample magnetic field environment and evaluate the optimal location of the single-axis magnetometer.
  
  
  RESULTS
  Given the different samples, the authors analysed the magnetic field distribution around the sample and determined the optimal orientation and possible positions of the sensor to maximize signal strength, that is, the power of the free induction decay. The authors demonstrate that a glass vial with flat bottom and 10 ml volume is the best structure to achieve the highest signal out of samples studied.
  
  
  CONCLUSIONS
  This paper demonstrates the importance of taking into account the combined effects of sensor configuration and sample parameters for signal generation prior to designing and constructing ULF systems with a single-axis magnetometer. Through numerical simulations the authors were able to optimize structural parameters, such as sample shape and size, sensor orientation and location, to maximize the measured signal in ultralow field relaxometry.
authors: Centre for Advanced Imaging, University of Queensland, Brisbane, St Lucia, QLD 4072, Australia. michael.vogel@cai.uq.edu.au
authors: Michael W
authors: MW
authors: Vogel
authors: Viktor
authors: V
authors: Vegh
authors: David C
authors: DC
authors: Reutens
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D060306:Magnetometry / Q000295:instrumentation*; D008962:Models, Theoretical