Abstract
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.
Original language | English |
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Pages (from-to) | 496-503 |
Number of pages | 8 |
Journal | Fizika Nizkikh Temperatur (Kharkov) |
Volume | 34 |
Issue number | 4-5 |
Publication status | Published - Apr 2008 |
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)