1,722,187 research outputs found
LAUNCHING OF ANTIPROTONS FROM THE CATCHING PENNING TRAP BY EVAPORATION METHOD
No full textIn this paper the launching of antiprotons from the catching Penning trap by evaporation method has been studied. The distributions of velocity and time-of-flight spectrum of launching antiprotons depend on the methods of reducing the trapping electric potential
Erratum: Comparison of classical and quantum models of anti-hydrogen formation through charge exchange (Journal of Physics B: Atomic, Molecular and Optical Physics (2019) 52 (115202) DOI: 10.1088/1361-6455/ab1151)
No full textA typographical error introduced during production is present in appendix B of this article. The word 'Schrödinger' is corrected to 'Schrödinger'. Additionally, figure 1 appears in lower quality in the published article than what was provided by the authors. This lower figure quality was introduced during production. A higher quality version is provided below, to improve the clarity of the authors' work. These changes do not affect the results of the article. (Figure Presented)
Comparison of classical and quantum models of anti-hydrogen formation through charge exchange
No full textWe compare classical and quantum predictions of the cross section for anti-hydrogen formation by charge exchange between Rydberg positronium and antiprotons as a function of the positronium energy. We show that these two highly different approaches furnish the same scaling law with the principal quantum number of positronium n Ps and numerical values in agreement within some tens of percent for and down to very low collision energy of tens of μeV. We discuss these results in the context of a recently claimed hypothesis of quantum suppression of the reaction driven by supposedly different scaling law of classical and quantum predictions. Finally we underline how the basic agreement between classical and quantum results enforces the reliability of the classical calculations that, presently, are the only ones able to obtain the cross section for positronium initially in high Rydberg states and in the presence of external electric and magnetic fields
ANTIHYDROGEN PRODUCTION IN A COMBINED TRAP
No full textIn this paper we study the properties of a Paul trap with a superimposed magnetic field (combined trap) and discuss the possibility of using this trap to simultaneously store positrons and antiprotons to form antihydrogen
ADIABATIC COOLING OF ANTIPROTONS IN A PENNING TRAP
No full textAn antiproton cloud cooled at 4.2 K in a Penning trap can be further cooled by adiabatic reduction of the trap magnetic and electric fields. It will be shown that the temperature can be reduced by two orders of magnitude. This cooling method may be useful to obtain ultra-low energy antiprotons for the measurement of their gravitational properties and the production of ultra-low energy antihydrogen atoms
ADIABATIC COOLING OF IONS IN THE PENNING TRAP
No full textAn ion cloud in a Penning trap can be cooled by adiabatic expansion by reducing the trap's magnetic and electric fields. We treat the ion cloud as a classical gas and obtain the relations between the temperature and the trapping fields. This cooling method may be useful in trapping and cooling of antiprotons with the aim of measuring the gravitational acceleration of antiprotons and other experiments on heavy ions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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