Download or read book Ionization of Diatomic Molecules in Intense Laser Fields written by Abdou Mekky Mousa Hussien and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ionization of Diatomic Molecules by Intense Laser Fields written by Justin Steele-Davies and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Dynamics and Ionization of Diatomic Molecules in Intense Laser Fields written by Maia Magrakvelidze and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we studied the dynamics of deuterium molecules in intense laser fields both experimentally and theoretically. For studying the dynamics of the molecule on a time scale that is less than the period of the laser field (2.7 fs for 800 nm), an advanced experimental technique: COLTRIMS (cold target recoil ion momentum spectroscopy) was used. COLTRIMS allows studying the nuclear dynamics without using attosecond laser pulses. This thesis consists of two main parts. In the first part we deduced the angular dependence of the ionization probability of the molecule without aligning the molecules, by measuring the relative angle between a deuteron resulting from field dissociation and an emitted electron using electron-ion coincidence measurements with circularly polarized light in COLTRIMS. We found out that for 50 fs pulses (1850 nm wavelength and 2 x10[superscript]14 W/cm[superscript]2 intensity), D[subscript]2 molecules are 1.15 times more likely to be ionized when the laser field is parallel to the molecular axis than when the laser field is perpendicular. This result agreed perfectly with the result from our ab initio theoretical model and also with predictions of the molecular Ammosov-Delone-Krainov (mo-ADK) theory. In the second part of this work we calculated the time evolution of an initial nuclear wave packet in D[subscript]2[superscript]+ generated by the rapid ionization of D[subscript]2 by an ultra short laser pulse. We Fourier transformed the nuclear probability density with respect to the delay between the pump and probe pulses and obtained two-dimensional internuclear-distance-dependent power spectra which serve as a tool for visualizing and analyzing the nuclear dynamics in D[subscript]2[superscript]+ in an external laser field. We attempt to model realistic laser pulses, therefore in addition to the main spike of the pulse we include the Gaussian pedestal. The optimal laser parameters for observing field-induced bond softening and bond hardening in D[subscript]2[superscript]+ can be achieved by varying the intensity, wavelength, and duration of the probe-pulse pedestal. Despite the implicit "continuum wave" (infinite pulse length) assumption the validity of the "Floquet picture" is tested for the interpretation of short-pulse laser-molecule interactions.
Download or read book Dynamics of Diatomic Molecules in Intense Laser Fields written by Mathias Uhlmann and published by . This book was released on 2006 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Diatomic Molecules in Intense Laser Fields written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A realistic description of ionization in intense laser fields is implemented into the Non-Adiabatic Quantum Molecular Dynamics (NA-QMD) formalism. First, the error of a finite basis expansion is considered and a new measure is proposed for time-dependent calculations. This is used to investigate systematically the influence of the used basis set in calculations on the hydrogen atom in intense laser fields. Second, absorbing boundary conditions in basis expansion are introduced via an imaginary potential into the effective one-particle Hamiltonian. It is shown that the used form of the absorber potential is valid in many-electron time-dependent density functional theory calculations, i.e. that only ionized states are affected by the absorbing potential. The absorber is then tested on reference calculations that exist for H and aligned H+2 in intense laser fields. Excellent agreement is found. Additionally, an approximative treatment of the missing electron-nuclear correlations is proposed. It is found in calculations on H+2 that a qualitative improvement of the description of nuclear dynamics results. The extension of the NA-QMD formalism is then used to investigate the alignment behavior of diatomic molecules. Recent experiments on H+2 and H2 are reviewed and explained. It is found that dynamic alignment, i.e. the laser induced rotation of the molecule, plays a central role. The alignment behavior of H+2 and H2 and its intensity dependence is investigated after that. A drastic difference between H+2 and H2 is found in NA-QMD as well as model calculations. Then, the focus is on an astonishing new effect that has been found in N2 calculations. This effect which is called "rotational destabilization" is studied on the model system H+2. Yet, it might be observable only in heavy dimers and might have already been found in an experiment on I2.
Download or read book Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields written by Jie Liu and published by Springer Science & Business Media. This book was released on 2013-09-30 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers in the field of laser physics, atom molecule physics and theoretical physics. Dr. Jie Liu is a professor of Institute of Applied Physics and Computational Mathematics, China and Peking University.
Download or read book Ionization and Dissociation Dynamics of Molecules in Strong Laser Fields written by Wei Lai and published by . This book was released on 2016 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The fast advancement of ultrashort-pulsed high-intensity laser technology allows for generating an electric field equivalent to the Coulomb field inside an atom or a molecule (e.g., Ec=5.14x109 V/cm at the 1s orbit radius a0=0.0529 nm of the hydrogen atom, which corresponds to an intensity of 3.54x1016 W/cm2). Atoms and molecules exposed in such a field will easily be ionized, as the external field is strong enough to remove the electrons from the core. This is usually referred to "strong field". Strong fields provide a new tool for studying the interaction of atoms and molecules with light in the nonlinear nonperturbative regime. During the past three decades, significant progress has been made in the strong field science. Today, most phenomena involving atoms in strong fields have been relatively well understood by the single-active-electron (SAE) approximation. However, the interpretation of these responses in molecules has encountered great difficulties. Not like atoms that only undergo excitation and ionization, various dissociation channels accompanying excitation and ionization can occur in molecules during the laser pulse interaction, which imparts further complexity to the study of molecules in strong fields. Previous studies have shown that molecules can behave significantly different from rare gas atoms in phenomena as simple as single and double ionization. Molecular dissociation following ionization also presents challenges in strong fields compared to what we have learned in the weak-field regime. This dissertation focuses on experimental studies on ionization and dissociation of some commonly-seen small molecules in strong laser fields. Previous work of molecules in strong fields will be briefly reviewed, particularly on some open questions about multiple dissociation channels, nonsequential double ionization, enhanced ionization and molecular alignment. The identification of various molecular dissociation channels by recent experimental technical upgrades will be shown. The study of enhanced ionization in small molecules by time-resolved pump-probe experiments and varying-pulse duration experiments will be discussed, followed by an investigation of molecular alignment effect in sequential and nonsequential dynamics. At last, selective charge separation in charge asymmetric dissociation of heteronuclear diatomic molecules will be shown and conclusion and future work will be discussed."--Pages vii-viii.
Download or read book Multielectron Effects of Diatomic Molecules in Strong Laser Fields written by Chunlei Guo and published by . This book was released on 1999 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecules in Laser Fields written by André D. Bandrauk and published by CRC Press. This book was released on 1993-12-14 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents the major advances in both intense laser fields phenomena and laser control of photochemical reactions - highlighting experimental and theoretical research on the interaction of simple molecules with intense laser fields. The book introduces new concepts such as above-threshold ionization (ATI), above-threshold dissociation (ATD), laser-induced avoided crossings, and coherent control.
Download or read book Molecules and Clusters in Intense Laser Fields written by Jan Posthumus and published by Cambridge University Press. This book was released on 2001-06-28 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough introduction to the subject, covering theory and experiments, for graduates and researchers.
Download or read book A Framework for Understanding Molecular Dynamics in Strong Laser Fields written by Saipriya V. Menon and published by . This book was released on 2002 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strong Field Laser Physics written by Thomas Brabec and published by Springer Science & Business Media. This book was released on 2008-09-10 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the rapid progress in laser technology a wealth of novel fundamental and applied applications of lasers in atomic and plasma physics have become possible. This book focuses on the interaction of high intensity lasers with matter. It reviews the state of the art of high power laser sources, intensity laser-atom and laser-plasma interactions, laser matter interaction at relativistic intensities, and QED with intense lasers.
Download or read book Diatomic Molecules in Strong Ultrashort Pulse Laser Fields written by John Paul Nibarger and published by . This book was released on 2000 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ionization of the Hydrogen Molecular Ion by Strong Infrared Laser Fields written by Tsogbayar Tsednee and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atoms Solids and Plasmas in Super Intense Laser Fields written by Dimitri Batani and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent developement of high power lasers, delivering femtosecond pulses of 20 2 intensities up to 10 W/cm , has led to the discovery of new phenomena in laser interactions with matter. At these enormous laser intensities, atoms, and molecules are exposed to extreme conditions and new phenomena occur, such as the very rapid multi photon ionization of atomic systems, the emission by these systems of very high order harmonics of the exciting laser light, the Coulomb explosion of molecules, and the acceleration of electrons close to the velocity of light. These phenomena generate new behaviour of bulk matter in intense laser fields, with great potential for wide ranging applications which include the study of ultra-fast processes, the development of high-frequency lasers, and the investigation of the properties of plasmas and condensed matter under extreme conditions of temperature and pressure. In particular, the concept of the "fast ignitor" approach to inertial confinement fusion (ICF) has been proposed, which is based on the separation of the compression and the ignition phases in laser-driven ICF. The aim of this course on "Atom, Solids and Plasmas in Super-Intense Laser fields" was to bring together senior researchers and students in atomic and molecular physics, laser physics, condensed matter and plasma physics, in order to review recent developments in high-intensity laser-matter interactions. The course was held at the Ettore Majorana International Centre for Scientific Culture in Erice from July 8 to July 14,2000.
Download or read book Intense Laser Phenomena and Related Subjects written by M. Yu Ivanov and published by . This book was released on 1991 with total page 587 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Probing Strong field Photoionization of Atoms and Diatomic Molecules with Short wave Infrared Radiation written by Max Möller and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The investigation of the interaction between atoms and diatomic molecules with strong laser fields with peak intensities in the range between ?10?^12 and ?10?^16 W/cm^2 has revealed fascinating phenomena such as high energy above-threshold ionization (HATI), non-sequential ionization (NSDI), high-harmonic generation (HHG) and frustrated tunnel ionization (FTI). Although experimental and theoretical considerations have shown that using longer laser wavelength is interesting from several aspects, the majority of measurements has been performed at laser wavelengths below 1.0 μm. Here, a laser source of intense femtosecond laser pulses with short-wave infrared (SWIR) wavelength is put to operation and applied to investigate strong-field photoionization (SFI) of atoms and diatomic molecules using two different experimental techniques for momentum spectroscopy of laser-induced fragmentation processes. Momentum distributions from strong-field photoionization of Xenon with different pulse duration are measured using the velocity map imaging technique. Besides observation of the pulse duration dependence a low-energy feature is investigated in detail. The corresponding modeling shows that the observations can be traced to rescattering between the laser-driven photoelectron and the remaining ion. SFI of the hydrogen molecular ion, H_2^+ (H_2^+?H^++H^++e^-), is investigated using Ion Target Recoil Ion Momentum Spectroscopy (ITRIMS). Besides measuring intensity dependent vector momentum distributions it is shown that momentum conservation can be used to extract the correlated electron momentum from the measured data, although the electron is not detected. This enables the analysis of the correlated electron-nuclear momentum distribution. Together, with a one-dimensional two-level model, this sheds light on correlated electron-nuclear ionization dynamics during SFI of diatomic molecules by SWIR fields.
