Optical properties of compressed fluid hydrogen in the region where dissociation and metallization is observed are computed by ab initio methods and compared with recent experimental results. We confirm that at T > 3,000 K, both processes are continuous, while at T < 1,500 K, the first-order phase transition is accompanied by a discontinuity of the dc conductivity and the thermal conductivity, while both the reflectivity and absorption coefficient vary rapidly but continuously. Our results support the recent analysis of National Ignition Facility (NIF) experiments [Celliers PM, et al. (2018) Science 361:677–682], which assigned the inception of metallization to pressures where the reflectivity is ∼0.3. Our results also support the conclusion that the temperature plateau seen in laser-heated diamond-anvil cell (DAC) experiments at temperatures higher than 1,500 K corresponds to the onset of optical absorption, not to the phase transition.
Rillo, Giovanni, et al. "Optical properties of high-pressure fluid hydrogen across molecular dissociation." Proceedings of the National Academy of Sciences of the United States of America, Apr. 2019. https://doi.org/10.1073/pnas.1818897116
Rillo, Giovanni, Morales, Miguel A., Ceperley, David M., & Pierleoni, Carlo (2019). Optical properties of high-pressure fluid hydrogen across molecular dissociation. Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.1818897116
Rillo, Giovanni, Morales, Miguel A., Ceperley, David M., et al., "Optical properties of high-pressure fluid hydrogen across molecular dissociation," Proceedings of the National Academy of Sciences of the United States of America (2019), https://doi.org/10.1073/pnas.1818897116
@article{osti_1509943,
author = {Rillo, Giovanni and Morales, Miguel A. and Ceperley, David M. and Pierleoni, Carlo},
title = {Optical properties of high-pressure fluid hydrogen across molecular dissociation},
annote = {
Optical properties of compressed fluid hydrogen in the region where dissociation and metallization is observed are computed by ab initio methods and compared with recent experimental results. We confirm that at
T
> 3,000 K, both processes are continuous, while at
T
Science
361:677–682], which assigned the inception of metallization to pressures where the reflectivity is ∼0.3. Our results also support the conclusion that the temperature plateau seen in laser-heated diamond-anvil cell (DAC) experiments at temperatures higher than 1,500 K corresponds to the onset of optical absorption, not to the phase transition.
},
doi = {10.1073/pnas.1818897116},
url = {https://www.osti.gov/biblio/1509943},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
issn = {ISSN 0027-8424},
place = {United States},
publisher = {National Academy of Sciences, Washington, DC (United States)},
year = {2019},
month = {04}}
Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America; ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)Copyright Statement
Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, Vol. 356, Issue 1735https://doi.org/10.1098/rsta.1998.0153