Spin Echo Formation in Presence of Fast Stochastic Dynamics

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

PHYSICAL REVIEW LETTERS

Año: 2007 vol. 99 p. 2630011 - 2630014

0031-9007

Spin echo formation in magnetic field gradients in the presence of fast stochastic motion is studied for hyperpolarized 3He gas at different diffusivities. The fast translational motion leads to frequency shifts already during echo formation, which can be described analytically for a linear gradient. Despite complete signal loss at the position of the spin echo itself, considerable intensity can be preserved at an earlier time (sqrt(2) au rather than 2 au, where au is the pulse delay). Hence, the phenomenon is designated as a pseudo spin