Diffusion spin echo suppression in the presence of inhomogeneous gradients

PAUL P. ZÄNKER; JOCHEN SCHMIDT; JÖRG SCHMIEDESKAMP; RODOLFO H. ACOSTA; HANS W. SPIESS

CHEMICAL PHYSICS LETTERS

Elsevier

Año: 2009 vol. 481 p. 137 - 141

0009-2614

A spin echo is usually expected to exhibit a maximum at a time 2\tau, where \teu is the pulse spacing; for high diffusivities in presence of linear gradients, however, a maximum is observed at times sqrt{2}tau. Here we show that in the presence of non-linear gradients a strong departure from the linear case is obtained. For long echo times a plateau for the maximum signal time is reached, thus a diffusion correlation time dependent both on the diffusion coefficient and the gradients strengths can be defined. Results for laser polarized 3He and 129Xe are compared with Monte Carlo simulations