Single-shot temporal envelope measurement of ultrashort extreme-UV pulses by spatially encoded transmission gating.

Single-shot ultrashort extreme-UV(EUV) pulse waveform measurement is demonstrated by utilizing strong field ionization of H2 gas for transmission gating. A cross-propagating intense near-IR gate pulse ionizes the EUV absorbing H2 molecules into EUV-non-absorbing H2++ (two protons) and creates a time sweep of transmission encoded spatially across the EUV pulse. The temporal envelope is then retrieved from the lopsided spatial profile of the transmitted pulse. This method not only measures EUV temporal envelope for each single shot, but also determines timing jitter and envelope fluctuation statistically, thus is particularly useful for characterizing low-repetition-rate fluctuating EUV/soft x-ray sources.

Divergent reactivity of nitric oxide with metal-metal quintuple bonds.

Reactions of NO with the quintuple bonded chromium and molybdenum amidinate dimers, respectively, gave dichromium nitrosyl nitrito amidinato complexes, and the quadruple bonded dimolybdenum nitrito amidinato species with a paddlewheel configuration.