CO2\mathrm{CO_2} exploding clusters dynamics probed by XUV fluorescence

Clusters excited by intense laser pulses are a unique source of warm dense matter, that has been the subject of intensive experimental studies. The majority of those investigations concerns atomic clusters, whereas the evolution of molecular clusters excited by intense laser pulses is less explored. In this work we trace the dynamics of $\mathrm{CO_2}$ clusters triggered by a few-cycle 1.45-$\mu$m driving pulse through the detection of XUV fluorescence induced by a delayed 800-nm ignition pulse. Striking differences among fluorescence dynamics from different ionic species are observed

Multi-channel electronic and vibrational dynamics in polyatomic resonant high-order harmonic generation

High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20-26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected

Low Carbon Footprint and Ultra Low NOx Boilers through Efficiency Gain

Benz Air Engineering and the CompuNOx system focus on a controls approach to minimize emissions without exposing steam generation plants to an unbearable financial burden. With minimal system changes we use thorough system analysis in conjunction with a novel control design to deliver a comprehensive boiler controls retrofit that provides reductions in emissions as well as substantial cost savings. Combining mechanical engineering expertise with substantial experience in control engineering in over 200 retrofits this system achieves astonishing results with short payback time, making CompuNOx a feasible solution for emission mandates and cost savings

NOx Reduction through Efficiency Gain

Benz Air Engineering and the CompuNOx system focus on a controls approach to minimize emissions without exposing steam generation plants to an unbearable financial burden. With minimal system changes we use thorough system analysis in conjunction with a novel control design to deliver a comprehensive boiler controls retrofit that provides reductions in emissions as well as substantial cost savings. Combining mechanical engineering expertise with substantial experience in control engineering in over 200 retrofits this system achieves astonishing results with short payback time, making CompuNOx a feasible solution for emission mandates and cost savings

Time-resolved Cluster Dynamics driven by 1.5-mu m Laser Pulses

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Comparing Femtosecond Multiphoton Dissociative Ionization of Tetrathiafulvene with Imaging Photoelectron Photoion Coincidence Spectroscopy

In this paper we describe femtosecond photoionization and the imaging photoelectron photoion coincidence spectroscopy of tetrathiafulvene, TTF. Femtosecond photoionization of TTF results in the absorption of up to twelve 808 nm photons leading to ion internal energies up to 12.1 eV as deduced from the photoelectron spectrum. Within this internal energy a variety of dissociation channels are accessible. In order to disentangle the complex ionic dissociation, we utilized the imaging photoelectron photoion coincidence (iPEPICO) technique. Above the dissociation threshold, iPEPICO results show that the molecular ion (<i>m</i>/<i>z</i> = 204) dissociates into seven product ions, six of which compete in a 1.0 eV internal energy window and are formed with the same appearance energy. Ab initio calculations are reported on the possible fragment ion structures of five dissociation channels as well as trajectories showing the loss of C₂H₂ and C₂H₂S from high internal energy TTF cations. A three-channel dissociation model is used to fit the PEPICO data in which two dissociation channels are treated as simple dissociations (one with a reverse barrier), while the rest involve a shared barrier. The two lower energy dissociation channels, <i>m</i>/<i>z</i> = 146 and the channel leading to <i>m</i>/<i>z</i> = 178, 171, 159, 140, and 127, have <i>E</i>₀ values of 2.77 ± 0.10 and 2.38 ± 0.10 eV, respectively, and are characterized by Δ<i>S</i>^‡_600 K values of −9 ± 6 and 1 ± 6 J K^–1 mol^–1, respectively. Competing with them at higher internal energy is the cleavage of the central bond to form the <i>m</i>/<i>z</i> = 102 fragment ion, with an <i>E</i>₀ value of 3.65 ± 0.10 eV and Δ<i>S</i>^‡_600 K = 83 ± 10 J K^–1 mol^–1

Comparing Femtosecond Multiphoton Dissociative Ionization of Tetrathiafulvene with Imaging Photoelectron Photoion Coincidence Spectroscopy

In this paper we describe femtosecond photoionization and the imaging photoelectron photoion coincidence spectroscopy of tetrathiafulvene, TTF. Femtosecond photoionization of TTF results in the absorption of up to twelve 808 nm photons leading to ion internal energies up to 12.1 eV as deduced from the photoelectron spectrum. Within this internal energy a variety of dissociation channels are accessible. In order to disentangle the complex ionic dissociation, we utilized the imaging photoelectron photoion coincidence (iPEPICO) technique. Above the dissociation threshold, iPEPICO results show that the molecular ion (<i>m</i>/<i>z</i> = 204) dissociates into seven product ions, six of which compete in a 1.0 eV internal energy window and are formed with the same appearance energy. Ab initio calculations are reported on the possible fragment ion structures of five dissociation channels as well as trajectories showing the loss of C₂H₂ and C₂H₂S from high internal energy TTF cations. A three-channel dissociation model is used to fit the PEPICO data in which two dissociation channels are treated as simple dissociations (one with a reverse barrier), while the rest involve a shared barrier. The two lower energy dissociation channels, <i>m</i>/<i>z</i> = 146 and the channel leading to <i>m</i>/<i>z</i> = 178, 171, 159, 140, and 127, have <i>E</i>₀ values of 2.77 ± 0.10 and 2.38 ± 0.10 eV, respectively, and are characterized by Δ<i>S</i>^‡_600 K values of −9 ± 6 and 1 ± 6 J K^–1 mol^–1, respectively. Competing with them at higher internal energy is the cleavage of the central bond to form the <i>m</i>/<i>z</i> = 102 fragment ion, with an <i>E</i>₀ value of 3.65 ± 0.10 eV and Δ<i>S</i>^‡_600 K = 83 ± 10 J K^–1 mol^–1