Single-shot mega-electronvolt ultrafast electron diffraction for structure dynamic studies of warm dense matter.

The Review of scientific instruments

PubMedID: 27910490

Mo MZ, Shen X, Chen Z, Li RK, Dunning M, Sokolowski-Tinten K, Zheng Q, Weathersby SP, Reid AH, Coffee R, Makasyuk I, Edstrom S, McCormick D, Jobe K, Hast C, Glenzer SH, Wang X. Single-shot mega-electronvolt ultrafast electron diffraction for structure dynamic studies of warm dense matter. Rev Sci Instrum. 2016;87(11):11D810.
We have developed a single-shot mega-electronvolt ultrafast-electron-diffraction system to measure the structural dynamics of warm dense matter. The electron probe in this system is featured by a kinetic energy of 3. 2 MeV and a total charge of 20 fC, with the FWHM pulse duration and spot size at sample of 350 fs and 120 ┬Ám respectively. We demonstrate its unique capability by visualizing the atomic structural changes of warm dense gold formed from a laser-excited 35-nm freestanding single-crystal gold foil. The temporal evolution of the Bragg peak intensity and of the liquid signal during solid-liquid phase transition are quantitatively determined. This experimental capability opens up an exciting opportunity to unravel the atomic dynamics of structural phase transitions in warm dense matter regime.