title: A field-sweep/field-lock system for superconducting magnets--Application to high-field EPR.
abstract: We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of +/-0.4 T and a resolution of up to 10(-5) T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR.
authors.affiliation: Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Maly
authors.forename: Jeff
authors.initials: J
authors.lastname: Bryant
authors.forename: David
authors.initials: D
authors.lastname: Ruben
authors.forename: Robert G
authors.initials: RG
authors.lastname: Griffin
mesh_terms: D004553:Electric Conductivity; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers