Temperature Dependence of the Proton Overhauser DNP Enhancements on Aqueous Solutions of Fremy's Salt Measured in a Magnetic Field of 9.2 T

The temperature dependence of the water-proton dynamic nuclear polarization (DNP) enhancement from Fremy's salt nitroxide radicals was measured in a magnetic field of 9.2 T (corresponding to 260 GHz microwave (MW) and 392 MHz NMR frequencies) in the temperature range of 15-65 °C. The temperature could be determined directly from the proton NMR line shift of the sample. Very high DNP enhancements of -38 (signal integral) or -81 (peak intensity) could be achieved with a high-power gyrotron MW source. The experimental findings are compared with classical Overhauser theory for liquids, which is based on the translational and rotational motion of the molecules and with molecular dynamics calculations of the coupling factor. © 2012 Springer-Verlag

Minimizing attosecond CEP jitter by carrier envelope phase tuning

Minimizing the CEP jitter of isolated attosecond pulses (IAP) will be important for future applications. This jitter is experimentally and theoretically investigated and can be minimized when the driving pulse is near its Fourier limit but with slightly negative chirp. Thus, understanding and characterization of the CEP jitter of IAPs is a first step towards exact control of the electric field of IAP pulses

Temperature Dependence of the Proton Overhauser DNP Enhancements on Aqueous Solutions of Fremy's Salt Measured in a Magnetic Field of 9.2 T

The temperature dependence of the water-proton dynamic nuclear polarization (DNP) enhancement from Fremy's salt nitroxide radicals was measured in a magnetic field of 9.2 T (corresponding to 260 GHz microwave (MW) and 392 MHz NMR frequencies) in the temperature range of 15-65 °C. The temperature could be determined directly from the proton NMR line shift of the sample. Very high DNP enhancements of -38 (signal integral) or -81 (peak intensity) could be achieved with a high-power gyrotron MW source. The experimental findings are compared with classical Overhauser theory for liquids, which is based on the translational and rotational motion of the molecules and with molecular dynamics calculations of the coupling factor. © 2012 Springer-Verlag

Temperature Dependence of the Proton Overhauser DNP Enhancements on Aqueous Solutions of Fremy's Salt Measured in a Magnetic Field of 9.2 T

The temperature dependence of the water-proton dynamic nuclear polarization (DNP) enhancement from Fremy's salt nitroxide radicals was measured in a magnetic field of 9.2 T (corresponding to 260 GHz microwave (MW) and 392 MHz NMR frequencies) in the temperature range of 15-65 °C. The temperature could be determined directly from the proton NMR line shift of the sample. Very high DNP enhancements of -38 (signal integral) or -81 (peak intensity) could be achieved with a high-power gyrotron MW source. The experimental findings are compared with classical Overhauser theory for liquids, which is based on the translational and rotational motion of the molecules and with molecular dynamics calculations of the coupling factor. © 2012 Springer-Verlag

Temperature Dependence of the Proton Overhauser DNP Enhancements on Aqueous Solutions of Fremy's Salt Measured in a Magnetic Field of 9.2 T

The temperature dependence of the water-proton dynamic nuclear polarization (DNP) enhancement from Fremy's salt nitroxide radicals was measured in a magnetic field of 9.2 T (corresponding to 260 GHz microwave (MW) and 392 MHz NMR frequencies) in the temperature range of 15-65 °C. The temperature could be determined directly from the proton NMR line shift of the sample. Very high DNP enhancements of -38 (signal integral) or -81 (peak intensity) could be achieved with a high-power gyrotron MW source. The experimental findings are compared with classical Overhauser theory for liquids, which is based on the translational and rotational motion of the molecules and with molecular dynamics calculations of the coupling factor. © 2012 Springer-Verlag

A PNR study of the off-specular scattering during the asymmetric magnetization reversal in an exchange-biased Co/CoO multilayer

We report on the observation of the effects of exchange bias on the magnetization reversal processes in a [Co/CoO/Au]20 system using polarized neutron reflectometry (PNR). The focus in this study is the investigation of the off-specular scattering of neutrons from magnetic domain structures during the magnetization reversal. In a previous PNR study on the same system, an asymmetry in magnetization reversal has been observed on opposite sides of the same hysteresis loop. For the decreasing field branch, the reversal was found to be dominated by domain wall motion of domains directed parallel or antiparallel to the applied field. In contrast, the reversal on the increasing field branch was characterized by rotation of magnetization. A significant loss of intensity was found for the specular reflected neutrons, while off-specular scattering experiments reveal that this magnetization reversal is not determined by coherent rotation but rather by a breaking up into smaller domains with different orientations.NRC publication: Ye