Measurement of nuclear spin relaxation time in lanthanum aluminate for development of polarized lanthanum target

Abstract

The nuclear spin-lattice relaxation time ($T_1$) of lanthanum and aluminum nuclei in a single crystal of lanthanum aluminate doped with neodymium ions is studied to estimate the feasibility of the dynamically polarized lanthanum target applicable to beam experiments. The application of our interest is the study of fundamental discrete symmetries in the spin optics of epithermal neutrons. This study requires a highly flexible choice of the applied magnetic field for neutron spin control and favors longer $T_1$ under lower magnetic field and at higher temperature. The $T_1$ of ${}^{139}\mathrm{La}$ and ${}^{27}\mathrm{Al}$ was measured under magnetic fields of $0.5$-$2.5$ T and at temperatures of $0.1$-$1.5$ K and found widely distributed up to 100 h. The result suggests that the $T_1$ can be as long as $T_1\sim$ 1 h at $0.1$ K with a magnetic field of $0.1$ T, which partially fulfills the requirement of the neutron beam experiment. Possible improvements to achieve a longer $T_1$ are discussed.

arXiv comment10 pages, 8 figures

References in corpus (4)

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• Measurements of polarized photo-pion production on longitudinally polarized HD and Implications for Convergence of the GDH Integral
• Transverse asymmetry of $\gamma$ rays from neutron-induced compound states of ${}^{140}\mathrm{La}$
• Development of portable NMR polarimeter system for polarized HD target