2026-09-23T08:04:11Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/25080 2023-07-10 col_2142_8859 col_2142_5131 com_2142_8858 com_2142_234 com_2142_5130

Stapleton, H.J. Wollan, David Strand 2011-05-31T17:41:22Z 2011-05-31T17:41:22Z 10000-01-01 1966 "Measurements of the dynamic polarization of protons by the solid state effect (""ef£et solide"") have been made at liquid helium temperatures on single crystals of erbium-doped and neodymium-doped yttrium ethyl sulphate ( (Er, Y)ES and (Nd, Y)ES). T he dynamic polarization was induced by saturating the forbidden, satellite electron spin resonance (ESR) line of the paramagnetic ion, and was measured by comparing proton nuclear magnetic resonance (NMR) signals. Becau.se of its higher hydrogen density, it was hoped that YES might be a better material than the commonly-used lanthanum magnesium nitrate (LaMN) for use as a polarized proton target for nuclear scattering experiments. Preliminary results on (Er, Y)ES at 9.5 Gc/sec showed several features that prohibit high proton polarizations. An anomalous behavior was observed in o 167 (Er, Y)E,:S at 2.0 K du~ to the overlap of one of the Er hyperfine lines with the main ESR transition, Preliminary experiments on (Nd, Y)ES at 9.5 Gc / sec indicated that this system was favorable for high polarizations. o Measqrements on (Nd, Y)ES at 69.5 Gc/sec, 16,200 Oe and 2.1 K gave a maximum proton polarization of 0.215, as compared with the ideal polarization of 0.66 expected under these conditions. The measured polarizations in this latter case were concentration independent for paramagnetic dopings from 0.25% to 2%. These results are in disagreement with Jeffries' ""shell-of-influence"" model and Borghini's density matrix theory of the solid state effect. Over 90% of the YES crystals o . cracked when cooled to 4.2 K. Because of thls and the low proton polarizations attained, (Nd, Y)ES is not recommended as a polarized proton target material for nuclear scattering experiments. Nonexponential proton NMR relaxation decays were observed in (Nd, Y)ES at 16,200 Oe and liquid helium temperatures." Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-31T17:41:22Z No. of bitstreams: 1 1966_wollan.pdf: 4545439 bytes, checksum: f064640c46ebef7856e999093da016dc (MD5) Made available in DSpace on 2011-05-31T17:41:22Z (GMT). No. of bitstreams: 1 1966_wollan.pdf: 4545439 bytes, checksum: f064640c46ebef7856e999093da016dc (MD5) Previous issue date: 1966 Restriction data tranferred 2014-07-01T11:14:46-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-31T17:41:22Z Item is restricted indefinitely. Thesis U of I Only 6120743 http://hdl.handle.net/2142/25080 en 1966 David Strand Wollan dynamic polarization of protons solid state effect liquid helium rare earth ethyl sulphates Dynamic proton polarization in some rare earth ethyl sulphates Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.