A5013029407- Atomic and Molecular Physics
- Muon and positron interactions and applications
- Graphene research and applications
- Particle accelerators and beam dynamics
- Astrophysics and Star Formation Studies
- Advanced Chemical Physics Studies
- Fullerene Chemistry and Applications
- Diamond and Carbon-based Materials Research
- Spectroscopy and Laser Applications
- Magneto-Optical Properties and Applications
- Spectroscopy and Quantum Chemical Studies
- Plasma Diagnostics and Applications
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Induction Heating and Inverter Technology
- Chemical Synthesis and Characterization
- Advancements in Battery Materials
- Ultrasound and Hyperthermia Applications
- Laser-Matter Interactions and Applications
- Material Properties and Failure Mechanisms
- Strong Light-Matter Interactions
- Nanotechnology research and applications
- Perovskite Materials and Applications
- Electron and X-Ray Spectroscopy Techniques
- Iron oxide chemistry and applications
Tokyo Metropolitan University
2020-2024
Rikkyo University
2020-2021
Tokyo University of Science
2013-2020
Mitsubishi Electric (Japan)
2002
The University of Tokyo
1968-1997
Nagaoka University of Technology
1993
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...
Junction type static induction transistor is designed as normally-off device, called bipolar mode (BSIT), where the channel completely pinched off by gate to built-in voltage, resulting in an appearance of potential barrier channel. Basic properties BSIT are discussed theoretically and experimentally. Possibilities high current speed switching performance has been demonstrated experimentally using sample having a cell size 800 × 520 µm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Magnetic loss angles of MnxFe3−xO4+γ(0≤x&lt;2) were observed at 101∼2 kHz by an automatic recording procedure from 4.2° to 400°K. Disconnection was confirmed between the lower temperature relaxation for x&lt;1 and higher x&gt;0.6. Two peaks separated below 50°K x = 0.3, 0.6, 0.7. Observation dielectric a microwave frequency have differentiated these electron-transfer relaxations single-ion electronic transition &gt; 1 very low temperatures. In general, change in heat...
The authors report a detailed study of the spontaneous decay and laser-induced delayed detachment associated with radiative cooling processes hot anions pentacene, prototypical member polycyclic aromatic hydrocarbon (PAH) family molecules. As an important constituent interstellar clouds, this molecule is particular interest to fields astrophysics astrochemistry.
We have observed radiative cooling of vibrationally excited C2– in the X2Σg+ electronic ground state via transitions to near-degenerate low-lying vibrational levels A2Πu state. Combining an ion storage technique with high-resolution detachment spectroscopy, we were able assign rovibronic resulting complex spectra. The time evolution population at specific states was measured up 60 ms, providing first quantitative experimental support for long-standing theoretical predictions.
Delayed electron detachment induced by resonant two-photon excitation of $\mathrm{C}{{}_{7}}^{\ensuremath{-}}$ is observed using an electrostatic ion storage ring. Radiative cooling during the period more than 100 ms considerably narrows initially very broad internal energy distributions resulting in delayed profiles to be well fitted single-exponential functions. The time constants decay, representing rate constants, are found much smaller theoretically predicted ones based on detailed...
Higher order mode (HOM) power excited in superconducting cavities can be on the of kW B-factory due to high current. To extract this power, are designed so that HOM travel out through beam pipes and absorbed a lossy material. Ferrite has been investigated as candidate material for absorber. Due its low tensile strength, bonding tiles problem. solve problem, we started R D sinter-bonding ferrite powder directly inner surface copper pipe using hot isostatic pressing. In paper, describe...
Recent results at the Slow Positron Facility (SPF), Institute of Materials Structure Science (IMSS), KEK are reported. Studies using total-reflection high-energy positron diffraction (TRHEPD) station revealed structures rutile-TiO2(110) (1×2), graphene on Cu (111) and Co (0001), germanene Al (111). First observations shape resonance in Ps− photodetachment process were made positronium negative ion (Ps−) station. Experiments time-of-flight (Ps-TOF) showed significant enhancement Ps formation...
We have measured the time-of-flight of ortho-positronium emitted from Cs-, Na- and Li-coated single-crystal tungsten surfaces. The data obtained after coating show a new positronium energy component with specific loss in addition to whose emission is simply determined by positron electron work functions. suggest that this attributed formation accompanied inter-band transition and/or surface plasmon excitation at
Time-of-flight spectra for the ortho-positronium emitted from clean and Na-coated tungsten surfaces have been measured using pulsed slow positron beam at KEK-IMSS facility. Emission efficiency of positronium sample was found to be several times greater than that uncoated surfaces.
The emission efficiencies of positronium atoms and negative ions from tungsten surfaces increase by alkali-metal coating. We have studied the coated using time-of-flight method. also performed observation photodetachment Ps− emitted a Na-coated surface production an energy-tunable Ps beam employing technique. This paper describes our recent studies surfaces.
Laser-induced delayed electron detachment from Si2– stored in an electrostatic ion storage ring was observed on the 10 microsecond time scale. The excitation spectra for photon energies near threshold show well-resolved multipeak structures, which are attributed to rovibronic transitions electronic excited state. This structure appears only signal measured with delay. occurrence of such a long scale is unusual diatomic molecules, suggesting that both autodetachment and fluorescence slow.
ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to "State-Selective Observation of Radiative Cooling Vibrationally Excited C2–"Shimpei Iida*Shimpei IidaMore by Shimpei Iidahttps://orcid.org/0000-0002-0432-4112, Susumu KumaSusumu KumaMore Kuma, Hajime TanumaHajime TanumaMore Tanuma, Toshiyuki AzumaToshiyuki AzumaMore Azuma, and Haruo ShiromaruHaruo ShiromaruMore ShiromaruCite this: J. Phys. Chem. Lett. 2021, 12, 37,...
Positronium formation at 4H SiC(0001) surfaces were investigated upon the removal of natural oxide layers by hydrofluoric acid etching and heat treatment 1000 K in ultra-high vacuum. Two types positronium observed time-of-flight (PsTOF) measurements irrespective conduction type surface polarity. One formed major part PsTOF spectrum with a maximum energy 4.7 ± 0.3 eV. This exceeded theoretical value calculated valence electrons. The shape was different from those metal surfaces, suggesting...
We have studied the emission of ortho-positronium from alkali-metal coated polycrystalline tungsten surfaces. The positronium time-of-flight spectra show that yield 5 eV component increases by coating. In addition, a low energy appears Cs or K suggest this is due to positron loss inter-band transition surface plasmon excitation.
Synopsis Generation of neutral atomic beam is under development for the ion-neutral merged-beam experiment at RIKEN Cryogenic Electrostatic ion storage ring (RICE). The produced by a photodetachment negative using high power laser diode array with wavelength 808 nm. In order to increase detachment efficiency, we have developed an optical cavity built planar mirror. this presentation will present current status atom source.