title: Phase boundary of hot dense fluid hydrogen.
abstract: We investigated the phase transformation of hot dense fluid hydrogen using static high-pressure laser-heating experiments in a laser-heated diamond anvil cell. The results show anomalies in the heating efficiency that are likely to be attributed to the phase transition from a diatomic to monoatomic fluid hydrogen (plasma phase transition) in the pressure range between 82 and 106 GPa. This study imposes tighter constraints on the location of the hydrogen plasma phase transition boundary and suggests higher critical point than that predicted by the theoretical calculations.
authors.affiliation: Center for Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.|Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohta
authors.affiliation: Center for Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Ichimaru
authors.affiliation: Center for Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Einaga
authors.affiliation: Center for Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Kawaguchi
authors.affiliation: Center for Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Center for Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Matsuoka
authors.affiliation: Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan.
authors.forename: Naohisa
authors.initials: N
authors.lastname: Hirao
authors.affiliation: Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohishi