We have measured magnetic fields up to 17.7 T with a rise time of 75 ns using temporally resolved Faraday rotation of a single longitudinal mode laser beam through a magneto-optically active bulk waveguide. We believe this to be the first time that such large, rapidly varying magnetic fields have been measured with this class of materials (multicomponent terbium borate glass). As there was no m...

The longitudinal relaxation time constant (T1) of the myocardium is altered in various disease states due to increased water content or other changes to the local molecular environment. Changes in both native T1 and T1 following administration of gadolinium (Gd) based contrast agents are considered important biomarkers and multiple methods have been suggested for quantifying myocardial T1 in vi...

Theoretical and experimental investigations into the thermal excitation of liquid paramagnetic contrast agents using the spin resonance relaxation mechanism are presented. The electronic spin-lattice relaxation time τ1e of gadolinium-based contrast agents, which is estimated at 0.1 ns, is ten orders of magnitude faster than the relaxation time of protons in water. The shorter relaxation time is...

Nonlinear longitudinal relaxation of a spin in a uniform external dc magnetic field is treated using a master equation for the quasiprobability distribution function of spin orientations in the configuration space of polar and azimuthal angles (analogous to the Wigner phase space distribution for translational motion). The solution of the corresponding classical problem of the rotational Browni...

We report on radical polarization and optically-driven liquid DNP using nitroxide radicals functionalized by photoexcitable fullerene derivatives. Pulse laser excitation of the fullerene moiety leads to transient nitroxide radical polarization that is one order of magnitude larger than that at the Boltzmann equilibrium. The life time of the radical polarization increases with the size of the fu...

The intracellular potassium content of perfused rat heart was measured by potassium-39 nuclear magnetic resonance (NMR) spectroscopy at 33 degrees C with an inversion recovery technique based on the fact that the spin-lattice relaxation time (T1) of the intracellular potassium (8.3 msec at 8.45 T) is much faster than that of the extracellular potassium (68 msec). Intracellular potassium decreas...

The stress and optical relaxation of an initially straight stiff polymer chain are studied through Brownian dynamics simulations (based on a semiflexible bead-rod model) covering a broad range of time scales and polymer lengths. The strong stress component sigma11 (where "1" is the direction of the original alignment) is shown to be associated with the chain's longitudinal relaxation while the ...

The Cu spin-lattice relaxation rate 1/T1 in UCu3.5Pd1.5 has been determined at frequencies 38 MHz<n0 <101 MHz and for temperatures 0.4 K<T<100 K. UCu3.5Pd1.5 was one of the first compounds revealing non-Fermi-liquid behavior which was explained in terms of a distribution of Kondo temperatures TK . In contrast to the broad distribution of single Kondo impurity temperatures TK , which accounted f...