Shen Ming, Roopchand Rabia, Mananga Eugene S, Amoureux Jean-Paul, Chen Qun, Boutis Gregory S, Hu Bingwen
Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China; UCCS, University Lille North of France, Villeneuve d׳Ascq 59652, France.
Department of Physics, Hunter College, New York, NY 10065, USA.
Solid State Nucl Magn Reson. 2015 Apr-May;66-67:45-48. doi: 10.1016/j.ssnmr.2014.12.004. Epub 2014 Dec 30.
Quadrupolar echo NMR spectroscopy of static solids often requires RF excitation that covers spectral widths exceeding 100 kHz, which is difficult to obtain due to instrumental limitations. In this work we revisit four well-known composite pulses (COM-I, II, III and IV) for broadband excitation in deuterium quadrupolar echo spectroscopy. These composite pulses are combined with several phase cycling schemes that were previously shown to decrease finite pulse width distortions in deuterium solid-echo experiments performed with two single pulses. The simulations and experiments show that COM-II and IV composite pulses combined with an 8-step phase cycling aid in achieving broadband excitation with limited pulse width distortions.
静态固体的四极回波核磁共振光谱通常需要覆盖超过100 kHz光谱宽度的射频激发，由于仪器限制，这很难实现。在这项工作中，我们重新审视了四种用于氘四极回波光谱宽带激发的著名复合脉冲（COM-I、II、III和IV）。这些复合脉冲与几种相位循环方案相结合，先前的研究表明，这些方案可减少在使用两个单脉冲进行的氘固体回波实验中的有限脉冲宽度失真。模拟和实验表明，COM-II和IV复合脉冲与8步相位循环相结合，有助于在有限的脉冲宽度失真下实现宽带激发。
