NMR measurement of quantized vortex lines in rotating He-3-B

In rotating He-3-B, the creation of a new vortex line gives rise to a disco ntinuous change in the NMR absorption amplitude. Such single-vortex steps h ave been observed at low magnetic fields similar to 10 mT and high temperat ures greater than or similar to 0.80T(c) with a signal-to-noise ratio of si milar to 10. To optimize this measurement, we have studied the discontinuou s signal at higher fields. We find that the resolution peaks at approximate ly 20 mT and decreases at higher fields. (C) 2000 Published by Elsevier Sci ence B.V. All rights reserved.