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Positronium hydride, or hydrogen positride〔 is an exotic molecule consisting of an exotic atom of positronium, which is a positron and electron in combination, and one of hydrogen. Its formula is PsH. It was predicted to exist in 1951 by A Ore,〔 〕 and subsequently studied theoretically, but was not observed until 1990. R. Pareja, R. Gonzalez from Madrid trapped positronium in hydrogen laden magnesia crystals. The trap was prepared by Yok Chen from the Oak Ridge National Laboratory.〔(【引用サイトリンク】page=9 )〕 In this experiment the positrons were thermalized so that they were not traveling at high speed, and they then reacted with H− ions in the crystal. In 1992 it was created in an experiment done by David M. Schrader and F.M. Jacobsen and others at the Aarhus University in Denmark. The researchers made the positronium hydride molecules by firing intense bursts of positrons into methane, which has the highest density of hydrogen atoms. Upon slowing down, the positrons were captured by ordinary electrons to form positronium atoms which then reacted with hydrogen atoms from the methane.〔 〕 ==Decay== PsH is constructed from one proton, two electrons, and one positron. The binding energy is . The lifetime of the molecule is 0.65 nanoseconds. Positronium deuteride also has the same lifetime.〔 The decay of positronium is easily detected by the two gamma ray photons produced with 0.511 MeV of energy. The energy of the photons from positronium should differ slightly by the binding energy of the molecule. However this has not yet been detected. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「positronium hydride」の詳細全文を読む スポンサード リンク
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