Observation of inhibited electron-ion coupling in strongly heated graphite

Journal article

Creating non-equilibrium states of matter with highly unequal electron and lattice temperatures (Tele≠Tion) allows unsurpassed insight into the dynamic coupling between electrons and ions through time-resolved energy relaxation measurements. Recent studies on low-temperature laser-heated graphite suggest a complex energy exchange when compared to other materials. To avoid problems related to surface preparation, crystal quality and poor understanding of the energy deposition and transport mechanisms, we apply a different energy deposition mechanism, via laser-accelerated protons, to isochorically and non-radiatively heat macroscopic graphite samples up to temperatures close to the melting threshold. Using time-resolved x ray diffraction, we show clear evidence of a very small electron-ion energy transfer, yielding approximately three times longer relaxation times than previously reported. This is indicative of the existence of an energy transfer bottleneck in non-equilibrium warm dense matter.

Authors: White, T; Vorberger, J; Brown, C; Crowley, B; Davis, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Nature
• Journal: Scientific Reports
• Volume: 2
• Article number: 889
• Publication date: 2012-11-27
• Acceptance date: 2012-11-08
• DOI: 10.1038/srep00889
• EISSN: 2045-2322
• Language: English
• Keywords: FFR