caa a22 4500 445365412 CHVBK 20180317142928.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s10909-010-0302-4 doi (NATIONALLICENCE)springer-10.1007/s10909-010-0302-4 Matrix Isolation of H Atoms at Low Temperatures [Elektronische Daten] [V. Khmelenko, D. Lee, S. Vasiliev] The recent history of the matrix isolation of atomic free radicals at low temperatures started with a research program at the US National Bureau of Standards and continued with the important breakthrough at Chernogolovka in Russia where a jet containing atomic free radicals was directed onto the surface of superfluid 4He. The samples collected consisted of gel-like substances made up of molecular nanoclusters, allowing the atomic free radicals to be isolated from one another and studied at 1.3 K. More recently, techniques were developed at Turku University which have been made the region T<1 K accessible for studies of H atoms entrapped in H2 films. Very high concentrations of H atomic free radicals (∼1018-1019cm−3) have been attained using both the Turku and Chernogolovka methods. Adiscussion of the most recent experiments at Cornell and Turku will be given. Microwave and mm wave electron paramagnetic resonance techniques have been employed in these experiments. These techniques permitted studies of the exchange tunneling chemical reaction D+HD→H+D2. Diffusion of H atoms through solid H2 proceeds via the reaction H+H2→H2+H, leading to recombination (H+H→H2). Quantum overlap of H atoms is thought to be responsible for exotic behavior of H atoms in solid H2 films below 1 K, including a significant departure from the Boltzmann distribution of the relative populations of the two lowest hyperfine levels of atomicH. Springer Science+Business Media, LLC, 2010 Atomic and molecular hydrogen nationallicence Matrix isolation nationallicence Free radicals nationallicence Electron spin resonance nationallicence Khmelenko V. Department of Physics and Astronomy, Texas A&M University, 77843, College Station, TX, USA aut Lee D. Department of Physics and Astronomy, Texas A&M University, 77843, College Station, TX, USA aut Vasiliev S. Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, 20014, Turku, Finland aut Journal of Low Temperature Physics Springer US; http://www.springer-ny.com 162/3-4(2011-02-01), 105-120 0022-2291 162:3-4<105 2011 162 10909 https://doi.org/10.1007/s10909-010-0302-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10909-010-0302-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Khmelenko V. Department of Physics and Astronomy, Texas A&M University, 77843, College Station, TX, USA aut NATIONALLICENCE 700 1- Lee D. Department of Physics and Astronomy, Texas A&M University, 77843, College Station, TX, USA aut NATIONALLICENCE 700 1- Vasiliev S. Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, 20014, Turku, Finland aut NATIONALLICENCE 773 0- Journal of Low Temperature Physics Springer US; http://www.springer-ny.com 162/3-4(2011-02-01), 105-120 0022-2291 162:3-4<105 2011 162 10909 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer