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Possible influence of thermal rotons on vortex nucleation by negative ions in pressurised HeII below 1 K.

Research output: Contribution to journalJournal article


<mark>Journal publication date</mark>14/08/1979
<mark>Journal</mark>Journal of Physics C: Solid State Physics
<mark>Original language</mark>English


A new technique has been developed for measuring the nucleation rate nu of negatively charged vortex rings in HeII when the temperature T, pressure P and electric field E are such that the bare-ion drift velocity is limited principally by roton emission. For P = 25 bar, E = 7.9 x l0^5 V/m and 0.7 < T < 0.9 K, the relation nu(T) = 8.0 x l0^7 exp( - 6.2/T) was obtained, which suggests that the magnitude of nu may be closely related to the thermal roton density