Beginnings of Developing Kinetic Scenarios of Plasma Evolution Due to Coulomb Collisions
Round 1
Reviewer 1 Report
Introduction is suitably presented with appropriate references.
Methods and equations are well presented and in detail explained. Reader with suitable background can easily follow the equations and their transformation. It would be suggested, to confirm the equations with results from numerical point of view and support it with result from graphs.
Conclusion is presented and presents the summary of the paper.
Author Response
I thank all reviewers for carefully reading the manuscript and providing useful comments.
According to the reviewers’ suggestion, I have revised the manuscript, and a highly qualified translator from Russian to English has helped me to professionally edit it, both in the sense of vocabulary and grammar.
The particular changes are:
on page 1, line 8 from the bottom, “ behavior” has been revised as “behaviour”
on page 2, line 26, “thermalization” has been revised as “thermalisation”
on page 3, line 25 and on page 6, line 19, “neighborhood” has been revised as “neighbourhood”
on page 2, line 13 from bottom, “infeasible” has been revised as “unfeasible”
on page 3, line 20, “the task of simultaneously integrating of infinitely many” has been revised as the “the task of simultaneously integrating infinitely many”
on page 3, the sentence “Just the formation of such a statistic was the result of the use of plasma ensemble averaging by our predecessors.” has been revised as “It was the construction of such statistics that was a consequence of the use of plasma ensemble averaging by our predecessors.”
Besides, the Reviewer's criticism of my English helped me to realize that some of my ideas were formulated without sufficient clarity. Accordingly, I have reformulated some phrases.
Regarding the suggested paper gaining, the following clarifications are in order:
The proposed work aims at developing the lowest-order approximation of the two-point correlation function that is most natural from the point of view of the possibility of the subsequent development of the most informative scenarios for the redistribution of plasma particles due to Coulomb collisions. In these scenarios, the nonlinear corrections to the Lenard-Balescu collision integral should also be displayed, and they should be derived from the proposed lowest-order approximation by means of iterations. They have the same order of smallness as the corrections developed in the manuscript. At the numerical level, the corrections of the above two conceptually different types cannot be separated. Accordingly, it is inappropriate to talk about numerical confirmation of the results of the proposed study, at least at the current stage of research. Likewise, a more detailed use of any graphs would hardly improve the presentation of the research motives and results.
Reviewer 2 Report
check english words and grammar
Author Response
I thank all reviewers for carefully reading the manuscript and providing useful comments.
According to the reviewers’ suggestion, I have revised the manuscript, and a highly qualified translator from Russian to English has helped me to professionally edit it, both in the sense of vocabulary and grammar.
The particular changes are:
on page 1, line 8 from the bottom, “ behavior” has been revised as “behaviour”
on page 2, line 26, “thermalization” has been revised as “thermalisation”
on page 3, line 25 and on page 6, line 19, “neighborhood” has been revised as “neighbourhood”
on page 2, line 13 from bottom, “infeasible” has been revised as “unfeasible”
on page 3, line 20, “the task of simultaneously integrating of infinitely many” has been revised as the “the task of simultaneously integrating infinitely many”
on page 3, the sentence “Just the formation of such a statistic was the result of the use of plasma ensemble averaging by our predecessors.” has been revised as “It was the construction of such statistics that was a consequence of the use of plasma ensemble averaging by our predecessors.”
Besides, the Reviewer's criticism of my English helped me to realize that some of my ideas were formulated without sufficient clarity. Accordingly, I have reformulated some phrases.
Reviewer 3 Report
Referee report
Beginnings of developing kinetic scenarios of plasma evolution due to Coulomb collisions
by Vasily I. Erofeev
This manuscript improves on a technique of reducing the description of plasma particles to a kinetic model without relying on the conventional ensemble averaging approach, for the specific problem of velocity redistribution due to Coulomb collisions in a homogeneous plasma. The key improvement is to provide a first-principles-based justification of the structure of the two-point correlation function.
Reading and understanding this manuscript is time-consuming because it is very original and relies on previous papers by the same author. The author may wish to improve on the pedagogy of the paper. However, in my opinion, this is a question of choice: the author may choose to write either a more self-contained but longer paper, or, as is the case here, a shorter paper that sends the reader to the relevant literature.
My main comment is simply that the English can be significantly improved, which would improve its readibility.
Let me end by listing a few more specific comments.
- I would advise to reduce self-citations, since 18 of 29 citations are publications by the same author.
- Page 2, ”infeasible”→”unfeasible”.
- Bottom of page 2, regarding the two-point correlation function, the author may cite recent applications to nuclear fusion such as [Y. Kosuga, et al.,Phys. Plasmas 21 (2014) 102303] and [P.H. Diamond, Y. Kosuga, M. Lesur,”Dynamics of structures in configuration space and phase space: an intro-ductory tutorial”, (book: Rotation and Momentum Transport in Magnetized Plasmas 81-113) (2015)].
- Page 3, ”integrating of infinitely many”→”integrating of infinitely many”.
- Page 3, ”Just the formation”→”The mere construction”. And I am sorry,but this is were I stop listing the English mistakes and strange formulations,because there are many more on pages 3 to 9 (pages 10 to 15 are fine).
Comments for author File: 
Comments.pdf
Author Response
I thank all reviewers for carefully reading the manuscript and providing useful comments.
According to the reviewers’ suggestion, I have revised the manuscript, and a highly qualified translator from Russian to English has helped me to professionally edit it, both in the sense of vocabulary and grammar.
The particular changes are:
on page 1, line 8 from the bottom, “ behavior” has been revised as “behaviour”
on page 2, line 26, “thermalization” has been revised as “thermalisation”
on page 3, line 25 and on page 6, line 19, “neighborhood” has been revised as “neighbourhood”
on page 2, line 13 from bottom, “infeasible” has been revised as “unfeasible”
on page 3, line 20, “the task of simultaneously integrating of infinitely many” has been revised as the “the task of simultaneously integrating infinitely many”
on page 3, the sentence “Just the formation of such a statistic was the result of the use of plasma ensemble averaging by our predecessors.” has been revised as “It was the construction of such statistics that was a consequence of the use of plasma ensemble averaging by our predecessors.”
The Reviewer's criticism of my English helped me to realize that some of my ideas were formulated without sufficient clarity. Accordingly, I have reformulated some phrases. In addition, I have added a footnote discussing the correspondence between my concept of the two-point correlation function and that used in the paper by Y. Kosuga, et al. [Phys. Plasmas 21 (2014) 102303]. The footnote has been added on page 4 and reads: "In this regard, our concept of the two-point correlation function differs substantially from the concepts of two-point functions that can be encountered in many papers that rely on traditional approaches. Particularly, we can point to the concept of phasestrophy (otherwise the two-point phase space density correlation~\cite{diamond2010physical}) mentioned in Ref.~\cite{doi:10.1063/1.4897179}. Although the concept of the latter object involves some averaging in phase space (called averaging over the spatial coordinate of the centre of mass), it was defined as the technical implementation of averaging over an ensemble of plasmas. The reference to this object is motivated by recalling exotic objects such as convective cells~\cite{doi:10.1063/1.871851} and phase space density granulations~\cite{Dupr_01,Dupr_2,doi:10.1063/1.866542}. Meanwhile, had these or any other exotic objects of the traditional plasma theory been of any importance for plasma physical manifestations, they would have contributed to our two-point correlation function, and their cumulative effect on plasma manifestations would have been adequately described by the equations of two-time formalism provided that the corresponding iterative procedure shows some asymptotic convergence.”
Regardless of this, I would like to clarify to the Reviewer the following aspect of the state of art in the kinetic modeling of plasma phenomena, which should surely be of importance for him. (I see that he can point to a huge number of traditional publications on plasma kinetics, which suggests that he is actively working in this field. In view of this, he should not ignore my achievements in the kinetics of turbulent plasmas: He would have learnt a lot, having familiarised himself with my papers.) You know, the practice of developing scientifically sound models of turbulent plasma phenomena should necessarily cover phenomena in weakly turbulent plasmas. Meanwhile, from the viewpoint of increasing the informativeness of plasma kinetic scenarios, the ideas of the traditional theory of weak plasma turbulence do not have appropriate scientific soundness. That is, they cannot help the researcher to formulate any reliable conclusions regarding the objective picture of plasma evolution in corresponding physical situations. I supply the reader of the paper with a list of publications that point to diverse illustrations of this truth, and there the reader cannot find even a pair of papers that duplicate each other. The most instructive of my illustrations is the concept of the collisionless dissipation of weak Langmuir turbulence: The traditional idea of this phenomenon is not consistent to observations in experiments on beam-plasma interactions. (The corresponding idea substantially undervalued the role of stochastic plasma electron acceleration that proceeds at the expense of the wave energy.) I hope that the above will help the Reviewer to better perceive the importance of focusing plasma kinetic studies on increasing the informativeness of plasma scenarios. In the paper, I explain once again the main reasons that lead to the unsoundness of plasma theoretical deductions in traditional approaches: The practice of replacing plasma by a plasma ensemble and ignoring the asymptotic nature of the theory convergence. (Meanwhile, the above-mentioned paper by Y. Kosuga, et al. uses the paradigm of plasma ensemble studies: averaging over a plasma ensemble.) Had the Reviewer penetrated the above position a bit deeper, he would quite likely have refrained from recommending me to shorten the list of references to my papers: They are referred to in view of the importance of developing the line of theorizing that I have been promoting for more than 20 years. Equally, the Reviewer's rebuke for taking a long time to read and understand my current research being time-consuming is just an indication of the fact that he did not ever thought about the ideas that I am advocating. I hope that he now realizes the importance of using these ideas in theoretical plasma research.
