Nuclear quadrupole resonance

About: Nuclear quadrupole resonance is a research topic. Over the lifetime, 3531 publications have been published within this topic receiving 38801 citations. The topic is also known as: Nuclear quadrupole resonance spectroscopy & NQR.

Nuclear quadrupole resonance detected at 30 MHz with a dc superconducting quantum interference device

Abstract: A dc superconducting quantum interference device is used as a tuned radio frequency amplifier at liquid helium temperatures to detect pulsed nuclear quadrupole resonance at ∼30 MHz. At a bath temperature of 4.2 K, a total system noise temperature of 6±1 K has been achieved, with a quality factor Q of 2500. A novel Q spoiler, consisting of a series array of Josephson tunnel junctions, reduces the ring‐down time of the tuned circuit after each pulse. The minimum number of Bohr magnetons observable from a free precession signal after a single pulse is ∼2×1016 in a bandwidth of 10 kHz.

Appearance of anisotropic non s-wave superconductivity above the critical pressure of antiferromagnetic CeRhIn5 - 115In nuclear quadrupole resonance study

Abstract: We have carried out 115In nuclear quadrupole resonance (NQR) measurements in CeRhIn5. At ambient pressure, CeRhIn5 undergoes an antiferromagnetic AF phase transition at \(\) K. The 115In NQR spectrum has shown the appearance of a small internal field in the direction perpendicular to the tetragonal c-axis. With application of a hydrostatic pressure, the AF state is suppressed and the superconductivity appears just above the critical pressure (P = 17 kbar). The nuclear spin lattice relaxation rate 1/T1 of 115In measured at P = 27 kbar indicates the occurrence of the superconductivity in the nearly AF region. In the superconducting state, 1/T1 has no Hebel-Slichter coherence peak just below \(\) of 2 K and has a power law T-dependence (T3) down to 300 mK. This is consistent with anisotropic superconductivity, with line nodes in the superconducting energy gap: non-s-wave superconductivity occurs in CeRhIn5.

Magnetic resonance detection coil that is immune to environmental noise

Abstract: A noise immuned gradiometer split shield coil for use in magnetic resonance detection, such as in Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR). The coil is formed by a transmission line (50) configured as a magnetic field gradiometer. The transmission line has a conductor (58) which is electrically continuous through the coil, and a shield (60) which is split (56) at a position that causes the gradiometer to be electrically balanced. In this manner, the coil provides a high degree of internal shielding to reduce the effect of environmental noise pick-up. Such coils are also less sensitive to the effects of nearby conducting media.