Spin Echo Sequence
Spin Echo Sequence - Related Videos
06:05
Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials
0 Views •
2014
Progress has been made in utilizing spin echo resolved grazing incidence scattering (SERGIS) as a neutron scattering technique to probe the length-scales in irregular samples. Crystallites of [6,6]-phenyl-C61-butyric acid methyl ester have been probed using the SERGIS technique and the results confirmed by optical and atomic force microscopy.
08:03
Study of Protein Dynamics via Neutron Spin Echo Spectroscopy
0 Views •
Cited by 4 •
2022
The present protocol describes methods for investigating the structure and dynamics of two model proteins that have an important role in human health. The technique combines bench-top biophysical characterization with neutron spin echo spectroscopy to access the dynamics at time and length scales relevant for protein interdomain motions.
01:06
Echo
0 Views •
2023
The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More than this, and they are perceived as separate sources. Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
10:02
Neutron Spin Echo Spectroscopy as a Unique Probe for Lipid Membrane Dynamics and Membrane-Protein Interactions
0 Views •
Cited by 5 •
2021
This paper describes the protocols for sample preparation, data reduction, and data analysis in neutron spin echo (NSE) studies of lipid membranes. Judicious deuterium labeling of lipids enables access to different membrane dynamics on mesoscopic length and time scales, over which vital biological processes occur.
10:00
Gradient Echo Quantum Memory in Warm Atomic Vapor
0 Views •
Cited by 2 •
2013
The gradient echo memory is a protocol for storing optical quantum states of light in atomic ensembles. Quantum memory is a key element of a quantum repeater, which can extend the range of quantum key distribution. We outline the operation of the scheme when implemented in a 3-level atomic ensemble.
FAQs
The 180-degree radiofrequency pulse reverses the phase relationships that have spread among tipped hydrogen nuclei. This phase reversal allows components that were diverging because of magnetic-field differences to converge and produce a measurable echo at a selected echo time. Its refocusing action helps preserve signal and supports more reliable biological tissue contrast.
Repetition time (TR) controls the interval between successive excitation cycles, whereas echo time (TE) determines when the refocused signal is sampled. Adjusting these timing variables changes the relative emphasis of T1 relaxation, T2 relaxation, or proton density. This flexibility lets investigators select contrast suited to anatomy, tissue composition, or disease-related biological changes.
Magnetic-field inhomogeneity causes nuclear spins to lose phase coherence, which can reduce the observed signal even when the tissue itself has not changed. The refocusing step compensates for this type of phase dispersion, making the sequence less vulnerable to that source of signal loss. In biological imaging, improved signal retention can support clearer assessment of tissue differences.
Contrast differences arise because biological tissues do not contribute identical relaxation or proton-density behavior under the same timing conditions. By selecting timing that emphasizes T1, T2, or proton density, investigators can highlight different aspects of tissue composition. The resulting images can help evaluate anatomy and characterize changes associated with disease or experimental biological structure.
Setup centers on choosing repetition time and echo time before signal acquisition. The selected repetition time governs how frequently the excitation pattern is repeated, while the echo time sets the point at which the refocused signal is observed. Researchers adjust these parameters according to whether the study prioritizes T1, T2, or proton-density contrast, then interpret the resulting tissue signal accordingly.
It is useful when a study needs MRI-based visualization of anatomy, tissue composition, or disease-related changes while limiting signal loss from magnetic-field inhomogeneity. The same approach can also support experimental studies of biological structure. Choice of timing allows one sequence family to address different imaging goals rather than restricting analysis to a single type of tissue contrast.