Author: Aaron LaForge Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Abstract: We explore the light induced dynamics in superfluid helium nanodroplets with wide-angle scattering in a pump-probe measurement scheme. The droplets are doped with xenon atoms to facilitate the ignition of a nanoplasma through irradiation with near-infrared laser pulses. After a variable time delay of up to 800 ps, we image the subsequent dynamics using intense extreme ultraviolet pulses from the FERMI free-electron laser. The recorded scattering images exhibit complex intensity fluctuations that are categorized based on their characteristic features. Systematic simulations of wide-angle diffraction patterns are performed, which can qualitatively explain the observed features by employing model shapes with both randomly distributed as well as structured, symmetric distortions. This points to a connection between the dynamics and the positions of the dopants in the droplets. In particular, the structured fluctuations might be governed by an underlying array of quantized vortices in the superfluid droplet as has been observed in previous small-angle diffraction experiments. Our results provide a basis for further investigations of dopant-droplet interactions and associated heating mechanisms
Author: Alkwin Slenczka Publisher: Springer Nature ISBN: 303094896X Category : Science Languages : en Pages : 590
Book Description
This open access book covers recent advances in experiments using the ultra-cold, very weakly perturbing superfluid environment provided by helium nanodroplets for high resolution spectroscopic, structural and dynamic studies of molecules and synthetic clusters. The recent infra-red, UV-Vis studies of radicals, molecules, clusters, ions and biomolecules, as well as laser dynamical and laser orientational studies, are reviewed. The Coulomb explosion studies of the uniquely quantum structures of small helium clusters, X-ray imaging of large droplets and electron diffraction of embedded molecules are also described. Particular emphasis is given to the synthesis and detection of new species by mass spectrometry and deposition electron microscopy.
Author: Camila Bacellar C Silveira Publisher: ISBN: Category : Languages : en Pages : 107
Book Description
Helium nanodroplets are the smallest known objects exhibiting superfluidity, and they provide a unique cryogenic matrix for high-resolution spectroscopy and ultracold chemistry applications. The relatively simple electronic structure of helium atoms and the homogeneity of the quantum fluid clusters make them excellent model systems for the study of electronic structures and dynamics in complex systems and the emergence of collective phenomena. Coupled electronic-nuclear dynamics in laser-excited helium nanodroplets are studied in the time-domain in two distinctly different excitation regimes following either single XUV-photon excitation or strong-field ionization by a near-infrared (NIR) laser pulse. Femtosecond time- resolved XUV photoelectron spectroscopy and femtosecond time-resolved X-ray coherent diffractive imaging are employed to monitor electronic relaxation dynamics in neutral droplets and the emergence and evolution of a nanoplasma in strong-field ionized droplets, respectively. Electronically excited pure and doped He droplets are prepared using femtosecond XUV pump pulses produced by high-order harmonic generation. The excited states and subsequent relaxation dynamics are probed by ionization of transient species with a femtosecond UV probe- pulse. Pump-probe time delay-dependent photoelectron kinetic energy distributions are measured using velocity map imaging. In pure droplets excited with 23.7 eV, three dynamic pathways are identified: interband relaxation from the initially excited 1s3p,1s4p manifold to the 1s2p band, further relaxation within the 1s2p Rydberg band and rapid atomic reconfiguration involving formation of Rydberg-excited (Hen)* cores within the droplet. Ongoing efforts towards understanding energy- and charge-transfer mechanisms between the host droplets and dopant atoms are discussed. New high-harmonic generation schemes were implemented in order to directly access the lower 1s2p droplet resonances. Droplets doped with a small amounts of Kr and Ne atoms (ndopant/ndroplet
Author: Eberhard J. Jaeschke Publisher: Springer ISBN: 9783319143934 Category : Science Languages : en Pages : 0
Book Description
Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources driven by laser-plasma accelerators. The applications of the most advanced light sources and the advent of nanobeams and fully coherent x-rays allow experiments from which scientists in the past could not even dream. Examples are the diffraction with nanometer resolution, imaging with a full 3D reconstruction of the object from a diffraction pattern, measuring the disorder in liquids with high spatial and temporal resolution. The 20th century was dedicated to the development and improvement of synchrotron light sources with an ever ongoing increase of brilliance. With ultrahigh brilliance sources, the 21st century will be the century of x-ray lasers and their applications. Thus, we are already close to the dream of condensed matter and biophysics: imaging single (macro)molecules and measuring their dynamics on the femtosecond timescale to produce movies with atomic resolution.
Author: Zhiming M. Wang Publisher: Springer Science & Business Media ISBN: 1461494729 Category : Technology & Engineering Languages : en Pages : 392
Book Description
Nanodroplets, the basis of complex and advanced nanostructures such as quantum rings, quantum dots and quantum dot clusters for future electronic and optoelectronic materials and devices, have attracted the interdisciplinary interest of chemists, physicists and engineers. This book combines experimental and theoretical analyses of nanosized droplets which reveal many attractive properties. Coverage includes nanodroplet synthesis, structure, unique behaviors and their nanofabrication, including chapters on focused ion beam, atomic force microscopy, molecular beam epitaxy and the "vapor-liquid- solid" route. Particular emphasis is given to the behavior of metallic nanodroplets, water nanodroplets and nanodroplets in polymer and metamaterial nanocomposites. The contributions of leading scientists and their research groups will provide readers with deeper insight into the chemical and physical mechanisms, properties, and potential applications of various nanodroplets.
Author: Kaoru Yamanouchi Publisher: Springer ISBN: 3319648403 Category : Science Languages : en Pages : 234
Book Description
This thirteenth volume in the PUILS series covers a broad range of topics from this interdisciplinary research field, focusing on atoms, molecules, and clusters interacting in intense laser field and high-order harmonics generation and their applications. The series delivers up-to-date reviews of progress in ultrafast intense laser science, the interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Typically, each chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries.
Author: Leonardo Palmisano Publisher: Elsevier ISBN: 0128242426 Category : Technology & Engineering Languages : en Pages : 488
Book Description
Photoelectrocatalysis: Fundamentals and Applications presents an in-depth review of the topic for students and researchersworking on photoelectrocatalysis-related subjects from pure chemistry to materials and environmental chemistry inorder to propose applications and new perspectives. The main advantage of a photoelectrocatalytic process is the mildexperimental conditions under which the reactions are carried out, which are often possible at atmospheric pressure androom temperature using cheap and nontoxic solvents (e.g., water), oxidants (e.g., O2 from the air), catalytic materials (e.g.,TiO2 on Ti layer), and the potential exploitation of solar light. This book presents the fundamentals and the applications of photoelectrocatalysis, such as hydrogen production fromwater splitting, the remediation of harmful compounds, and CO2 reduction. Photoelectrocatalytic reactors and lightsources, in addition to kinetic aspects, are presented along with an exploration of the relationship between photocatalysisand electrocatalysis. In addition, photocorrosion issues and the application of selective photoelectrocatalytic organictransformations, which is now a growing field of research, are also reported. Finally, the advantages/disadvantages andfuture perspectives of photoelectrocatalysis are highlighted through the possibility of working at a pilot/industrial scale inenvironmentally friendly conditions. Presents the fundamentals of photoelectrocatalysis Outlines photoelectrocatalytic green chemistry Reviews photoelectrocatalytic remediation of harmful compounds, hydrogen production, and CO2 reduction Includes photocorrosion, photoelectrocatalytic reactors, and modeling along with kinetic aspects
Author: Anders Lund Publisher: Springer ISBN: 3319092162 Category : Science Languages : en Pages : 766
Book Description
Applications of EPR in Radiation Research is a multi-author contributed volume presented in eight themes: I. Elementary radiation processes (in situ and low temperature radiolysis, quantum solids); II: Solid state radiation chemistry (crystalline, amorphous and heterogeneous systems); III: Biochemistry, biophysics and biology applications (radicals in biomaterials, spin trapping, free-radical-induced DNA damage); IV: Materials science (polymeric and electronic materials, materials for treatment of nuclear waste, irradiated food); V: Radiation metrology (EPR-dosimetry, retrospective and medical applications); VI: Geological dating; VII: Advanced techniques (PELDOR, ESE and ENDOR spectroscopy, matrix isolation); VIII: Theoretical tools (density-functional calculations, spectrum simulations).
Author: Aaron LaForge
Author: Alkwin Slenczka
Author: Camila Bacellar C Silveira
Author: Eberhard J. Jaeschke
Author: 
Author: Zhiming M. Wang
Author: Kaoru Yamanouchi
Author: Reginald William Blake Pearse
Author: Leonardo Palmisano
Author: Anders Lund