Electron attachment to atomic hydrogen on the surface of liquid ⁴He

• Дата: 2008
• Автори: Arai, T., Yayama, H., Kono, K.
• Формат: Стаття
• Мова: English
• Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2008
• Назва видання: Физика низких температур
• Теми: Электроны над жидким гелием
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/116927
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Electron attachment to atomic hydrogen on the surface of liquid ⁴He / T. Arai, H. Yayama, K. Kono // Физика низких температур. — 2008. — Т. 34, № 4-5. — С. 496–503. — Бібліогр.: 28 назв. — англ.

We demonstrate a possibility that helium surface electrons at cryogenic temperatures can be used as a new source of very low energy electrons. Since both electrons (e¯) and hydrogen atoms (H) are bound on liquid helium surface, two-dimensional mixture gas of these two species is available on the surface. We found that low energy collision of e¯ and H drives electron attachment to form a negative hydrogen ion (H¯) in the mixture. From our temperature dependence measurement of the reaction rate, it was found that another H atom participate in the reaction. Namely, the reaction is expressed as H + H + e¯ → H¯ + H. Possible reaction mechanisms are discussed in terms of direct three-body process and dissociative attachment process. Measurements in applied magnetic field (B) show that the reaction rate coefficient is suppressed as ~ B⁻². This implies that electron spin singlet collision is relevant for electron attachment.