Panguluri R P, Suits B H
Physics Department, Michigan Technological University, Houghton, MI, USA.
J Magn Reson. 2006 Sep;182(1):49-54. doi: 10.1016/j.jmr.2006.06.008. Epub 2006 Jun 27.
Theoretical and experimental results are presented for the case of Zeeman perturbed nuclear quadrupole resonance (NQR) using spin-3/2 nuclei with a small Zeeman interaction, gammaB0, while the sample is very slowly rotated. It is found that the decay envelope for a simple two-pulse echo measurement can be strongly affected even though the sample may rotate only a few degrees or less during the course of the measurement. To lowest order the decay envelope can be described using a one dimensional function of the product of gammaB0, the rotation rate, and the square of the pulse spacing. Aside from an indirect and weak dependence on the quadrupole asymmetry parameter, eta, the result is independent of the NQR frequency. Identical results are expected for a stationary sample in a small rotating magnetic field. The effect seen here may be used to advantage to measure rotational motion, for example of particles in fluids, or may be an additional complication for some Zeeman perturbed NQR measurements, including some NQR detection and imaging methods.
本文给出了使用具有小塞曼相互作用（γB0）的自旋3/2原子核，在样品非常缓慢旋转的情况下，塞曼微扰核四极共振（NQR）的理论和实验结果。结果发现，即使在测量过程中样品可能仅旋转几度或更小角度，简单的双脉冲回波测量的衰减包络也会受到强烈影响。最低阶的衰减包络可以用γB0、旋转速率和脉冲间隔平方的乘积的一维函数来描述。除了对四极不对称参数η有间接且微弱的依赖外，结果与NQR频率无关。对于处于小旋转磁场中的静止样品，预计会得到相同的结果。这里观察到的效应可用于测量旋转运动，例如流体中粒子的旋转运动，或者对于一些塞曼微扰NQR测量（包括一些NQR检测和成像方法）可能是一个额外的复杂因素。
