DEVELOPMENT OF A HIGH RESOLUTION NMR SCATTERING SYSTEM

基于自旋相干输运的NMR散射 偶极相互作用是我们正在开发的一个新领域。 做出 有意义的测量，必须在其上创建磁化光栅 样品的螺距与 偶极耦合自旋对 这就需要有足够的梯度场 i04 G/cm。 我们已经开发出一种方法， 它可以被精细地控制， 梯度为100，000 G/cm，1，000 A。我们还开发了一个强大的 开关电路，其在这些位置提供可控电流脉冲 程度. 重要的特征是快速切换时间， 重复性和稳定性的梯度系统在一个强大的 背景字段。 在过去的一年里我们重建了光谱仪 为了提高脉冲编程器的分辨率和光谱分辨率， 纯度 此外，探头已重建，包括一个gomometer。

NMR scattering based on spin coherence transport mediated through dipolar interactions is a new field that we are developing. To make a meaningful measurement a magnetization grating must be created across the sample with a pitch comparable to the interspin distance of a dipolarly coupled spin pair. This demands gradient fields in excess of i04 G/cm. We have developed a means of creating pulsed gradients that can be finely controlled and which will deliver a magnetic field gradient of 100,000 G/cm at 1,000 A. We have also developed a robust switching circuit that delivers controllable current pulses at these levels. Important characteristics are fast switching times, repeatability and the stability of the gradient system in a strong background field. Over the past year we have rebuilt the spectrometer to improve the resolution of the pulse programmer and the spectral purity. Also the probe has been rebuilt to include a gomometer.