{'fraction_non_alphanumeric': 0.038506417736289385, 'fraction_numerical': 0.004667444574095682, 'mean_word_length': 5.042253521126761, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Formation mechanisms and properties of electron spin echoes in solids

In addition to the ordinary Hahn mechanism of electron spin echoes (ESEs), i.e. the non-linear amplitude-dependent excitation of spin precession, two new mechanisms, namely amplitude-dependent shift Delta omega (Mz) of resonance frequency (pulling) and amplitude-dependent damping Gamma (Mz)=T2-1(Mz) (Mz is the z component of the magnetization), are proposed. The latter two mechanisms are due to the effect of instantaneous diffusion. A qualitative picture and a quantitative theory of ESEs in solids are elaborated, taking into account all three non-linear mechanisms. A new method based on the modulation effect of echo damping is presented to obtain the parameters T1, T2 and Delta omega . The modulation effect is due to the simultaneous action of the three non-linear mechanisms.