title: Relaxation calorimeter for hydrogen thermoporometry.
abstract: A relaxation calorimeter for measuring the heat capacity of hydrogen isotopes in nanoporous solids is described. Apparatus' features include (i) cooling by a pulse tube refrigerator, (ii) a modular design, allowing for rapid reconfiguration and sample turn around, (iii) a thermal stability of ≲1 mK, and (iv) a bottom temperature of ~5 K. The calorimeter is tested on effective heat capacity measurements of H2 in Vycor (silica) nanoporous glass, yielding a very detailed pore size distribution analysis with an effectively sub-Angstrom resolution.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: E
authors.initials: E
authors.lastname: Van Cleve
authors.forename: M A
authors.initials: MA
authors.lastname: Worsley
authors.forename: S O
authors.initials: SO
authors.lastname: Kucheyev