Design and implementation of a J-coupled spectrometer for multidimensional structure and relaxation detection at low magnetic fields. - Kaseman, Derrick C.; Magnelind, Per E.; Widgeon Paisner, Scarlett; Yoder, Jacob L.; Alvarez, Marc; Urbaitis, Algis V.; Janicke, Michael T.; Nath, Pulak; Espy, Michelle A.; Williams, Robert F. (Review of Scientific Instruments, 2020)