A5037463697- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Laser-induced spectroscopy and plasma
- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- Spectroscopy and Laser Applications
- Quantum, superfluid, helium dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Subatomic Physics Research
- Ion-surface interactions and analysis
- Laser-Matter Interactions and Applications
- Plasma Diagnostics and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Laser-Plasma Interactions and Diagnostics
- Astrophysics and Star Formation Studies
- Fullerene Chemistry and Applications
- Spectroscopy and Quantum Chemical Studies
- Nuclear Physics and Applications
- Analytical Chemistry and Chromatography
- Atmospheric Ozone and Climate
- Diamond and Carbon-based Materials Research
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Advancements in Photolithography Techniques
- Laser Design and Applications
Tokyo Metropolitan University
2015-2025
University of Gothenburg
2009
Osaka University
2004-2008
Institute for Laser Technology
2008
Kansai Photon Science Institute
2008
Hiroshima University
2008
Tohoku University
1987-1995
Niigata University
1995
Nagoya Institute of Technology
1995
Extreme ultraviolet (EUV) radiation from laser-produced plasma (LPP) has been thoroughly studied for application in mass production of next-generation semiconductor devices. One critical issue the realization an LPP-EUV light source lithography is conversion efficiency (CE) incident laser power to EUV 13.5-nm wavelength (within 2% bandwidth). Another solving problem damage caused when debris reaches collecting mirror. Here, we present improved balance model, which can be used optimization...
Abstract Ejected material from neutron star mergers gives rise to electromagnetic emission powered by radioactive decays of r -process nuclei, the so-called kilonova or macronova. While properties are largely affected opacities in ejected material, available atomic data for elements still limited. We perform structure calculations elements: Se ( Z = 34), Ru 44), Te 52), Ba 56), Nd 60), and Er 68). confirm that bound–bound transitions open f -shell, lanthanide (Nd Er) higher than those other...
We report conclusive evidence of an efficient cooling mechanism via the electronic radiative transitions hot small molecular anions isolated in vacuum. stored ${{\mathrm{C}}_{6}}^{\ensuremath{-}}$ and ${\mathrm{C}}_{6}{\mathrm{H}}^{\ensuremath{-}}$ ion storage ring observed laser-induced electron detachment with delays up to several milliseconds. The terminal hydrogen atom caused a drastic change decay profiles. photoexcited is slow nonexponential, which can be explained by depletion...
The ionization of protic molecules such as H2O and NH3 in the condensed phase initiates ion–molecule reactions, which remain poorly understood. Studies structure reactivity small ionic clusters molecular beams have yielded a wealth information on protonated clusters. However, unprotonated radical cation low concentration typical experiment thus challenging. Here we report infrared spectra (NH3)2+ (NH3)3+ cations solvated helium nanodroplets. Radical often several isomers with different...
We have detected visible photons emitted from the thermally populated electronic excited state, namely recurrent fluorescence (RF), of ${\mathrm{C}}_{6}^{\ensuremath{-}}$ stored in an electrostatic ion storage ring. Clear evidence is provided to distinguish RF normal fluorescence, based on temporal profile synchronized with revolution ring, for which time scale far longer than lifetime intact photoexcited state. The relaxation (cooling) process via likely be commonplace isolated molecular...
Atomic processes in Sn plasmas are investigated for application to extreme-ultraviolet (EUV) light sources used microlithography. We develop a full collisional radiative (CR) model of based on calculated atomic data using Hebrew University Lawrence Livermore Code (HULLAC). Resonance and satellite lines from singly multiply excited states ions, which contribute significantly the EUV emission, identified included through systematic investigation their effect emission spectra. The wavelengths...
Charge state specific euv spectra from a range of tin ions have been recorded at Tokyo Metropolitan University. The were produced charge-exchange collisions between and helium atoms using an electron cyclotron resonance source. At low target gas pressures, the dominated by single capture events. were, unexpectedly, found to be intense unresolved transition array near 13 nm while lines, including previously identified $4p\ensuremath{-}4d$ ${^{1}S}_{0}\ensuremath{\rightarrow}{^{1}P}_{1}$ line...
Extreme ultraviolet emission spectra of multiply charged Sn ions were measured in the wavelength range 5–38 nm, following electron capture into excited states slow Snq + (q = 5–21) passing through He and Xe gas targets. Identification transitions was carried out by comparison with calculations using Hebrew University Livermore Laboratory Atomic physics Code. The target charge-state dependences 4d–nℓ (nℓ 4f, 5p 5f) 4p–4d observed.
Photon induced decay of \documentclass[12pt]{minimal}\begin{document}${\rm C}_5^-$\end{document}C5− has been measured in an electrostatic storage ring. The time dependence the photo-enhanced is close to a 1/t which indicates thermal process. deviation from expected power −1 quantitatively explained by small heat capacity anion. Measurements at different times and photon energies allow determination radiative cooling rate energy distribution ions. average content between 15 70 ms found vary...
The structure of the minimum unit radical cationic water clusters, (H2O)2+ dimer, has attracted much attention because its importance for radiation chemistry water. Previous spectroscopic studies indicated that dimers have a proton-transferred (H3O+·OH), though alternate metastable hemibonded (H2O·OH2)+ was also predicted based on theoretical calculations. Here, we produce in superfluid helium nanodroplets and study their infrared spectra range OH stretching vibrations. observed indicate...
The spontaneous and photo-induced neutralization of C₇⁻ produced in a laser ablation source was measured an electrostatic storage ring. measurements provide three independent determinations the radiative cooling ions, based on short time decay integrated amplitude shape signal. signal between 0.5 ms 35 found to depend photon wavelength ion time. All signals can be reproduced with identical thermal IR rates oscillator strengths equal theoretical predictions. In addition, excitation energy...
Inverse internal conversion followed by recurrent fluorescence was observed as a fast decay (10 μs range) in the time profile of neutral yields from photo-excited C4(-) molecular ions. We also elucidated contribution such electronic radiative cooling to ions with energy far below detachment threshold an alternative novel approach, observing laser wavelength and storage dependence (ms total yield photo-induced neutrals.
We have measured extreme ultraviolet (EUV) spectra from highly charged tin ions in low-density and high-temperature plasmas produced the Large Helical Device at National Institute for Fusion Science. The EUV emitted after injection of a pellet into hydrogen plasma were monitored by grazing incidence spectrometer whose wavelength resolution is about 0.01 nm. Two different types spectral feature 13–17 nm region depending on whether discharge was stably sustained or underwent radiation...
Out-of-band (OOB) radiation (at wavelengths longer than 130nm) from an extreme ultraviolet (EUV) light source reduces the precision of lithography. The energy OOB laser-produced Sn plasmas were measured by using absolutely calibrated transmission grating spectrometer equipped with a charge-coupled device. dependence radiant on mass and size tin fuel was clarified. dominant is peripheral heating around laser spot via electron thermal conduction high-temperature EUV emission region.
ABSTRACT The radiative cooling rates of C$_N^+$ clusters (N = 9, 11, 12, 17–27) have been measured in the ultrahigh vacuum an electrostatic storage ring to values on order 104 s−1. were as a competing channel unimolecular decay, and rate constants pertain excitation energies where these two channels compete. Such high can only be explained photon emission from thermally excited electronic states, mechanism that has also seen polycyclic aromatic hydrocarbon cations. very strong stabilizing...
The cooling rates of ${\mathrm{C}}_{60}^{\ensuremath{-}}$ have been measured in an electrostatic storage ring between several hundred $\ensuremath{\mu}\mathrm{s}$ and tens ms with one-photon laser excitation. absolute energy scale is established by the photon energy, time interval derived from nonexponential decay ensemble hot molecules. decreases due to combined action depletion thermal emission IR photons a total loss rate that varies inversely proportional time, $0.9\text{ }\text{...
A new, compact electrostatic storage ring for atomic and molecular physics is planned to be built at RIKEN, Japan. The new will cooled down below 10 K store rotationally cold ions a long period.
Delayed electron detachment yields of ${{\mathrm{C}}_{4}}^{\ensuremath{-}}$ and ${{\mathrm{C}}_{6}}^{\ensuremath{-}}$ induced by photoexcitation in an electrostatic ion storage ring were measured as functions excitation energies laser firing times, allowing for a mapping their radiative cooling wide energy range. The window concept discrimination one- two-photon absorption are critical understanding the obtained results. experimentally electronic vibrational rates consistent with simulation...
Extreme ultra-violet emission spectra of multiply charged Xe and Sn ions are measured following the electron capture in collisions with He. After assumption singleelectron capture, we have found that wide range charge states, Sn10+ to Sn14+ for tin ions, Xe11+ Xe17+for xenon prominent emissions at 13.5 11.0 nm, respectively. These attributed 4d-4f unresolved transition arrays comparison results theoretical calculations by using HULLAC code.