First Simulations for the EuAPS Betatron Radiation Source: A Dedicated Radiation Calculation Code
, Alessandro Cianchi 3,4, Alessandro Curcio 5, Illya Drebot 1, Massimo Ferrario 5, Vittoria Petrillo 1,6, Marcello Rossetti Conti 1, Sanae Samsam 1, Luca Serafini 1 and Andrea Renato Rossi 1Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript describes simulations of a betatron source and the efforts made in treating the simulated particles in order to get realistic results.
The idea of the paper is sound but in the current version it lacks something to be considered more than an internal status report.
In the abstract there are hints to the possibility of applying the whole machinery to study shot-to-shot variation, but later in the manuscript there is no trace. That could be an interesting way to increase the content.
The section 2.1 in “materials and methods” seems more suitable for an appendix, unless the value of this particular structure is somehow lifted. As far as understood, the script is external to the PIC code, and its general value is it not unfolded.
Figure 4a shows a little discrepancy on the left side of the main peak, is this understood?
Is the code benchmarked against experimental results? I would be good for the paper to add some testing cases.
Author Response
We thank the Referee for the useful comments. The Referee will find attached a pdf file with both answers to the raised points and the edited manuscript.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsComments for author File: Comments.pdf
Not particular problems found. Maybe I would try to make shorter sentences, when possible.
Author Response
We thank the Referee for the detailed comments. We appeciate the effort in reviewing our paper.
The Referee will find attached a pdf file with a brief response to each comment and the edited manuscript.
We are open to further discussion and editing to enhance the manuscript's clarity and value.
Sincerely,
Andrea Frazzitta
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe manuscript reports on the development of a code to retrieve the X-ray radiation spectrum (and angular distribution) due to so-called betatron emission from LWFA electron beams, starting with the particle trajectories as provided by PIC codes (in this case, SMILEI).
The authors first lay out a description of the algorithms developed to identify, extract and sort the figures for the self-injected particles contributing to the X-ray emission, and then describe their "forward" (i.e., starting with the trajectories data at the timesteps provided by the PIC code, and allowing for uneven timesteps at the detector position) approach to the calculation of the emission spectrum.
The manuscript is very clear and complete.
Even in view of both the growing interest the topic has been deserving and the relatively still "unmature" literature on the specific topic, I would recommend the publication of the manuscript. I would at the same time ask the authors to improve the quality of the introductive presentation of the field, possibly by including references to recent related works.
Author Response
We are pleased to hear that the Referee finds the manuscript clear and complete, and we thank the Referee for recommending it for publication.
In response to Referee's suggestion regarding the introductory presentation of the field, we have made some revisions to provide a concise but more detailed description of the mechanism underlying X-ray radiation emission (Introduction section). We have also incorporated three additional citations that touch upon both theoretical aspects and experimental measurements related to self-injection mechanisms and betatron radiation in general.
For Referee's convenience, we have attached the revised manuscript. Please note that there are highlighted sections, which pertain to modifications made based on comments from another Referee.
We look forward to any further comments or suggestions.
Sincerely,
Andrea Frazzitta
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe answers are satisfactory and the changes implemented in the manuscript improved it overall.
