Non-Standard Bruker Pulse Program Commands

The use of variable spin system parameters and the visualization of magnetization vectors using the Bloch simulator module require additional commands to be implemented in the NMR-SIM pulse programs that do not appear in the standard BRUKER pulse programs. The increment or decrement of a spin system parameter is triggered by a command line in the pulse program. The Bloch simulator module uses the increment of the virtual chemical shift to generate the offset dependence of a pulse. 

A typical application for these commands is to display the excitation profile of a pulse or shaped pulse as a spectrum. The frequency of the pulse is held constant and the chemical shift of a spin is incremented. The signal intensity is then measured as a function of the frequency difference or offset between the spin s chemical shift and the pulse frequency. This method essentially corresponds to a sweep over the excitation range of the pulse and offers an alternative representation to the Bloch simulator approach. 

Load the configuration file dsweep.cfg. Open the spin system file (Edit Spin system...) and note the spin system variable definition. Examine the pulse sequence (Edit Pulse program...) and note the additional loop command to increment the chemical shift. Using the GolRun Experiment command simulate the spectrum which corresponds to the excitation profile of a 90° TOPHAT pulse. In 1D WIN-NMR process the FID using zero filling of Sl(r+i) 32/cand an exponential window function with a LB value of 2 Hz. 

The Bloch simulator module in NMR-SIM enables the offset dependence between the frequency of a pulse and the resonance frequency of an uncoupled single spin to be visualized graphically in a manner similar to the diagrams in the literature. Essentially the Bloch equations describe two simultaneous processes the effect of a radio frequency pulse on a macroscopic magnetization vector and the relaxation of the macroscopic magnetization back to its equilibrium value with the assumption that the Ti and T2 relaxation can be treated as a simple first order process. The NMR-SIM Bloch 

After the ze command the command line 1 sample is inserted. 

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