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Measurement of the spin diffusion rate of dipolar order in single crystal calcium fluoride

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dc.contributor.advisor David G. Cory. en_US Boutis, Gregory Steven, 1975- en_US
dc.contributor.other Massachusetts Institute of Technology. Dept. of Nuclear Engineering. en_US 2006-03-24T18:11:29Z 2006-03-24T18:11:29Z 2002 en_US 2002 en_US
dc.description Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2002. en_US
dc.description Includes bibliographical references (leaves 69-74). en_US
dc.description.abstract This thesis reports on the first measurement of the spin diffusion rate of a two-spin correlated state, known as dipolar order, in a single crystal of calcium fluoride. The experimental results for the component of the spin diffusion rate parallel with the azimuthal axis are ... for the [001] direction and ... for the [111] direction. These rates are significantly faster than those for Zeeman order and are also faster than theories have predicted. The standard method of measuring diffusion in magnetic resonance is to encode a spatial modulation of magnetization in a sample and then measure it's attenuation over time. The difficulty in measuring spin diffusion in solid crystals by these scattering methods is that the spin diffusion rate is very slow (of order 1 x 10⁻¹² cm²/s) and hence the displacement of coherence is very small. The experimental challenge for probing these dynamics is that a modulation must be created with a wavelength on these length scales. To perform the measurement a special probe was developed with a gradient coil constant of 370±10.5[G/cmA]. A special holder was designed for holding the 1mm³ sample in addition to a gradient switcher for switching pulsed currents through the coil. The peak pulsed gradient strengths ranged from 28 to 85 T/m and the spatial wavelengths generated ranged from 1[mu] to 0.5 [mu]/tm. en_US
dc.description.abstract (cont.) Additional work focuses on correcting for finite pulse widths effects, phase transients and other pulse errors in a time-reversal multiple-pulse cycle known as the magic-echo sequence. The highest resolution achieved was a line-width of 0.5 Hz in a single crystal of calcium fluoride whose natural line-width was approximately 45 kHz, a reduction by 5 orders of magnitude. A phase alternating scheme for generating and detecting high order n-spin azimuthal spin correlations ... was also investigated. The relaxation times of 2, 3 and 4 spin correlations were was found to be comparable to that of dipolar order. en_US
dc.description.statementofresponsibility by Gregory Steven Boutis. en_US
dc.format.extent 74 leaves en_US
dc.format.extent 2726457 bytes
dc.format.extent 2726262 bytes
dc.format.mimetype application/pdf
dc.format.mimetype application/pdf
dc.language.iso eng en_US
dc.publisher Massachusetts Institute of Technology en_US
dc.rights M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. en_US
dc.subject Nuclear Engineering. en_US
dc.title Measurement of the spin diffusion rate of dipolar order in single crystal calcium fluoride en_US
dc.type Thesis en_US Ph.D. en_US
dc.contributor.department Massachusetts Institute of Technology. Dept. of Nuclear Engineering. en_US
dc.identifier.oclc 55012299 en_US

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