Coincidence Spectroscopies

(VMI and COLTRIMS)

In the vacuum and extreme ultraviolet regions of the spectrum, light-matter interaction is dominated by photoionization. All molecules and materias absorb strongly in the vacuum ultraviolet region of the spectrum. In molecular systems, the sudden excitation or removal of an electron will initiate ultrafast electronic and nuclear dynamics that are strongly correlated. In nanosystems irradiated by ultrafast UV-VUV-EUV pulses, solvated electrons can be created, or exciton dynamics can be probed.

High harmonic sources, when combined with coincidence reaction microscopes such as VMI and COLTRIMS, can disentangle the complex ultrafast charge dynamics in highly excited systems relevant to atmospheric chemistry, or in nano-enhanced systems relevant to energy science –

• VUV and EUV high harmonics can directly access excited states in neutral atoms, molecules, clusters and ions, as well as initiating and probing excited state dynamics in nanoparticles and nano-droplets
• Electron-ion coincidence techniques benefit from very high repetition rates for good signal-to-noise (>10kHz), making KMLabs’ high average power lasers and VUV-EUV XUUS source ideal for VMI and COLTRIMS
• Highly excited states have short lifetimes: high harmonics are an ideal probe of rich excited state landscapes