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Quarterly progress report for Q2 FY06 for Complex Transient Events in Materials Studied Using Ultrafast Electron Probes and Terascale Simulation (FWP SCW0289) (open access)

Quarterly progress report for Q2 FY06 for Complex Transient Events in Materials Studied Using Ultrafast Electron Probes and Terascale Simulation (FWP SCW0289)

In this quarter (Q2 FY06), the DTEM underwent a substantial reconfiguration of its laser systems. The cathode laser system was changed to provide greater numbers of electrons per pulse by lengthening the time duration of the pulse to 30 ns. The greater number of electrons per pulse has allowed us to acquire high quality pulsed images and diffraction patterns. The spatial resolution in the single pulsed image has been measured at better than 20 nm. The diffraction patterns are now more comparable to conventional electron microscope operation. Examples are found in the body of the report. We summarize important achievements in the following list: (1) Instrument performance and design improvements--(A) The laser system was changed for the cathode photoemission system (75 ns at 1053 nm wavelength converted to 30ns at 211 nm wavelength) to give longer electron pulses at the same current to yield more electrons per pulse. (B) New specimen drive laser constructed. (C) New computer monitored and controlled alignment systems installed for both laser systems to facilitate laser alignment through a user friendly computer interface. (2) Experimental Progress--(A) The spatial resolution of pulsed images was tested by imaging a cross-section of multilayer thin foils with 30 nm and …
Date: March 29, 2006
Creator: Campbell, G. H.
System: The UNT Digital Library