The Carr-Purcell-Meiboom-Gill (CPMG) Sequence is a pulse sequence in NMR spectroscopy that involves a series of 180° pulses applied to transverse magnetization to enhance signal detection and reduce decoherence effects.

2023年1月30日 · CPMG is a very useful technique for SSNMR spectroscopists. It uses a train of π π pulses to refocus inhomogeneous broadening of the nuclear spins. This is very beneficial and can be used to enhance S/N, measure diffusion, measure T 2 processes, and reduce experimental time.

cpmg序列总结 在X轴方向施加90°脉冲，此时Mxy=M0为最大值，将该时刻作为时间原点，之后分别在t、3t、5t,···，（2n-1）t时刻施加180°脉冲，然后对应的分别在在2t、4t、6t、 ···，2nt得到回波，其得到的磁化量为：

在核磁共振(NMR)光谱学与核磁共振成像中,弛豫时间是一个十分重要的概念,它描述了核自旋磁矩从不平衡态恢复到平衡态的过程,或者说,它描述了核自旋“忘记”它们初始方向,并在各种不同机制的作用下恢复到热平衡态的速度。 由于弛豫时间直接反映了不同物质内部核磁矩的相互作用,因此可以用来区分不同的物质,是核磁共振成像的理论基础。...

The Carr-Purcell-Meiboom-Gill sequence (CPMG) experiment allows to measure transverse or spin-spin T 2 relaxation times of any nucleus. The experimental half-height linewidth (d) of a given resonance is directly related to T 2 * by the equation

The CPMG (Carr-Purcell-Meiboom-Gill) pulse train is a fundamental component of pulse sequences used for the measurement of dynamic processes by NMR spectroscopy. As reported in his seminal paper of 1950, Hahn discovered that when two successive radio-frequency pulses, separated by a time interval τ, are applied to an ensemble of spins, a ...

2016年8月24日 · CPMG sequence is one of the important means to measure transverse relaxation time of the sample. The CPMG sequence involves applying not a single 90 degree RF pulse to the sample, but many 180 degree pulses. Each time a 180 degree pulse is applied, the signal decay to the magnetic field is removed and a single data point is acquired.

NMR Method: Principles of NMR and Processing Spin-Echo and CPMG Pulse Sequence. Once the 90° B 1 pulse is turned off, the proton begin to de-phase or lose phase coherency in B 0 (Figure 3‑14). As the net magnetization in the transverse plane decreases, a receiver coil that measures the magnetization in the transverse direction could detect a ...

2020年9月14日 · Detection and quantification of low molecular weight components in polymeric samples via nuclear magnetic resonance (NMR) spectroscopy can be difficult due to overlapping signal caused by line broadening characteristics of polymers.

Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion NMR experiments are extremely powerful for characterizing millisecond time-scale conformational exchange processes in biomolecules. A large number of such CPMG experiments have now emerged for measuring protein backbone chemical shifts of sparse …