Timothy E. Chupp

Learn More
The feasibility of brain MRI with laser-polarized 129Xe in a small animal model is demonstrated. Naturally abundant 129Xe is polarized and introduced into the lungs of Sprague-Dawley rats. Polarized xenon gas dissolves in the blood and is transported to the brain where it accumulates in brain tissue. Spectroscopic studies reveal a single, dominant,(More)
The first magnetic resonance imaging studies of laser-polarized (129)Xe, dissolved in the blood and tissue of the lungs and the heart of Sprague-Dawley rats, are described. (129)Xe resonances at 0, 192, 199, and 210 ppm were observed and assigned to xenon in gas, fat, tissue, and blood, respectively. One-dimensional chemical-shift imaging (CSI) reveals(More)
The neutron longitudinal and transverse asymmetries A n 1 and A n 2 have been extracted from deep inelas-tic scattering of polarized electrons by a polarized 3 He target at incident energies of 19.42, 22.66 and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions g n 1 (x; Q 2) and g n 2 (x; Q 2) over the range(More)
We present a Next-to-Leading order perturbative QCD analysis of world data on the spin dependent structure functions g p 1 , g n 1 , and g d 1 , including the new experimental information on the Q 2 dependence of g n 1. Careful attention is paid to the experimental and theoretical uncertainties. The data constrain the first moments of the polarized valence(More)
We report the results of an improved determination of the triple correlation DP·(p(e)×p(v)) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96±1.89(stat)±1.01(sys)]×10(-4). The corresponding phase between gA and gV is ϕAV=180.013°±0.028°(More)
We report on an improved determination of the parity-even, time-reversal-odd triple correlation, D < J n > ·(p e × p v), in the decay of cold polarized neutrons. Within the Standard Model, final state interactions give rise to D ∼ 10 −5 and are calculable to better than 1%[1]. Thus, measurement of D can provide a clear signal of time-reversal invariance(More)
A perfusion phantom with unique features and a wide variety of applications in MR and other imaging modalities is presented. Using microfabrication technique, a network of microchannels, in the scale of actual microvasculature, was created. The geometry of the network was determined based on Murrays minimum work law to simulate the hemodynamic in actual(More)
Prior studies revealed neutron beam-induced alkali-metal spin relaxation in 3 He cells polarized in-situ by spin-exchange optical pumping. These effects are minor for neutron beams of low to moderate intensity, but become important at the highest neutron flux levels available in the full spectrum beams of high flux neutron sources. It was found that the(More)
ACKNOWLEDGEMENTS Many people aided me in the work contained in this thesis. First among these is my advisor, Tim, whose patience and guidance is infused in all of the work presented here and has been much appreciated. Professor Lorenzon has been almost a second advisor to me, providing insightful feedback on my analysis techniques and invaluable assistance(More)