Spin echo without an external permanent magnetic field

TL;DR

This paper proposes an iterative pulse sequence method to generate spin echoes without the need for an external permanent magnetic field, avoiding alterations to the medium's natural magnetic response.

Contribution

It introduces a novel iterative scheme for spin echo generation that eliminates the requirement of an external magnetic field, preserving the medium's natural dynamics.

Findings

Sequence length improves echo approximation

Method eliminates external magnetic field requirement

Potential for non-invasive magnetic resonance applications

Abstract

The spin echo techniques aim at the elimination of the effect of a random magnetic field on the spin evolution. These techniques conventionally utlize the application of a permanent field which is much stronger than the random one. The strong field, however, may also modify the magnetic response of the medium containing the spins, thus altering their ``natural'' dynamics. We suggest an iterative scheme for generating a sequence of pulses which create an echo without an external permanent field. The approximation to the ideal echo improves with the sequence length.