Takayuki Tachibana

TL;DR: The experimental field developed in the present work gives new opportunities to explore the quantum mechanical three-body problem and to develop energy-tunable positronium beams.

TL;DR: In this article, the converter/moderator assembly was modified for slow positron beam production, yielding an increase of an order of magnitude in the intensity of the beam, and the first observation of the photodetachment of the positronium negative ion (Ps−), and the installation of a reflection high energy positron diffraction (RHEPD) station and the initial data obtained are reported.

TL;DR: In this article, the emission of positronium negative ions from Na- and K-coated W(100) surfaces has been studied and the emission efficiencies for both samples were found to be as high as 1.5%.

TL;DR: In this article, an energy-tunable mono-energetic positronium beam was produced using photodetachment of the POS negative ion, a bound state of one positron and two electrons, by bombarding a Na-coated tungsten surface with a pulsed slow positron beam and accelerated using a static electric field.

TL;DR: In this article, the authors measured the time-of-flight spectra of ortho-positronium atoms emitted from polycrystalline tungsten surfaces with and without a sodium coating and showed a significant increase on coating in the yield of the 5 eV component due to positronium formed from thermalized positrons and conduction electrons.