کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8203026 1530503 2018 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Free energy and spatial periodicity of generalized cnoidal ion holes
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک و نجوم (عمومی)
پیش نمایش صفحه اول مقاله
Free energy and spatial periodicity of generalized cnoidal ion holes
چکیده انگلیسی
The free energy density of an ion hole excited coherent state plasma is calculated. The underlying ion trapping nonlinearity is shown to support expressions which appear one order earlier in the expansion scheme compared with conventional, linearly based derivations. This energy argument hence provides a further hint for the necessity of a full nonlinear Vlasov equation in describing coherent wave phenomena found ubiquitously in space, lab and fusion plasmas. The most prominent holes, the privileged cnoidal ion holes, being characterized by regularly trapped ions, can achieve states of lower energy than the ones of the unperturbed plasma and are hence attractors in the nonlinear dynamical evolution being approached in long term runs. Such negative energy holes can also be found by an extended description of holes that admits singularities of the trapped ion distribution fit, namely a moderate slope singularity at the separatrix of fit. A stronger singularity in form of a jump of fit at the boundary of the trapped ion region, on the other hand, results in a positive energy expression and is already for this reason less probable. As a biproduct, a novel expression is obtained for the wave length of a cnoidal ion hole in terms of the other relevant parameters.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physics Letters A - Volume 382, Issue 37, 22 September 2018, Pages 2693-2699
نویسندگان
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