The Cherenkov Camera for the PBR Mission

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

  I have read the manuscript and I provide here a list of (mainly minor) comments: 

- line 14: UHECR is not defined in terms of which energies it refers to 
- line 18: 'their extremely high energies make them rare' is very unclear without a specific reference to the spectral index of the CR spectrum.
- line 43 vs line 57: the different values provided for the field of view are confusing. I could guess that the camera has a smaller FoV than the telescope? (but in line 43 it is unclear what 'total field of view' means), but here it is significantly smaller (1/12 exactly?) It deserves a further explanation. 
- line 58: it is not clear why 'splitting the light' improves background rejection. This sentence requires some additional explanation. 
- Fig.2 vs the list in page 3 (lines 63++) : I recommend to adopt the same notation in the text and in the figures. Currently in Figure 2 there is no reference to 'HAHA'. Please make the figure consistent with the rest of the manuscript
- line 77: the sentence 'with the Earth as a neutrino converter', is awkward for a non specialist: first it is not clear if something is converted to neutrino, or neutrino are converted to something else. Then 'converter' is a poor choice because it might mean 'transmutation' in the sense, for example of photon-axion conversion, or neutrino oscillation. Here the neutrino is not 'converted' to tau, it just interacts with matter, and produce as an outcome of the interaction 'also' a tau.  Please rephrase. 
- line 94: 'within the EUSO structure' is unclear. Maybe 'within the EUSO collaboration'? or equivalent? 
- line 107: this measurements -> these mesaurements 
- the 'conclusion' section is too short: please provide a short summary of the previous pages, and then finalize with the plans for PBR.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding changes in the re-submitted files. The reviewer's comments are in italics for better readability.

Reviewer's comment	Author's response
line 14: UHECR is not defined in terms of which energies it refers to line 18: 'their extremely high energies make them rare' is very unclear without a specific reference to the spectral index of the CR spectrum.	Changes applied for both comments, adding also a reference
line 43 vs line 57: the different values provided for the field of view are confusing. I could guess that the camera has a smaller FoV than the telescope? (but in line 43 it is unclear what 'total field of view' means), but here it is significantly smaller (1/12 exactly?) It deserves a further explanation.	Yes, the camera has a small field of view. Most of the field of view is occupied by the Fluorescence Camera. Furthermore, due to power budget and weight issues, it was not possible to fill all the remaining space with the Cerenkov Camera.
line 58: it is not clear why 'splitting the light' improves background rejection. This sentence requires some additional explanation.	Modified text
Fig.2 vs the list in page 3 (lines 63++) : I recommend to adopt the same notation in the text and in the figures. Currently in Figure 2 there is no reference to 'HAHA'. Please make the figure consistent with the rest of the manuscript	Changed with a more general figure
line 77: the sentence 'with the Earth as a neutrino converter', is awkward for a non specialist: first it is not clear if something is converted to neutrino, or neutrino are converted to something else. Then 'converter' is a poor choice because it might mean 'transmutation' in the sense, for example of photon-axion conversion, or neutrino oscillation. Here the neutrino is not 'converted' to tau, it just interacts with matter, and produce as an outcome of the interaction 'also' a tau.  Please rephrase.  - line 94: 'within the EUSO structure' is unclear. Maybe 'within the EUSO collaboration'? or equivalent?  - line 107: this measurements -> these mesaurements  - the 'conclusion' section is too short: please provide a short summary of the previous pages, and then finalize with the plans for PBR.	All changes have been implemented.

Thank you, I am available for any further comments.

Beatrice Panico

 

Reviewer 2 Report

Comments and Suggestions for Authors

There are differences among different values considered in this paper in comparison with other papers of the group (I believe that the group can specify this at the beginning of the work).

Fig.1. can contain more information on the position of each type of detector (it seems a black box, in the present presentation). A separation of the figure caption on the work text is necessary, too. 

A short explanation of the connection between the modification of the angular acceptance and energies of the incoming particles is necessary. 

There are some difficulties in the understanding of the neutrino search. Some references could help here. 

Some details and references on simulations and predictions based on these simulations are useful in the third and fourth pages. 

A correction in the second proposition from the row 107 is useful, too. 

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding changes in the re-submitted files. The reviewer's comments are in italics for better readability.

Reviewer's comment	Author's response
Quality of English Language:The English could be improved to more clearly express the research.	I tried to reformulate some phrases to be more clear.
Does the introduction provide sufficient background and include all relevant references?Is the research design appropriate?                              Are the methods adequately described?                                  Are all figures and tables clear and well-presented?                Are the results clearly presented?	Changes have been made to improve the article, also following the point-by-point comments.
There are differences among different values considered in this paper in comparison with other papers of the group (I believe that the group can specify this at the beginning of the work).	Unfortunately, I'm not sure what values you're referring to. I think I entered  the official ones. Could you let me report, please? Thanks
Fig.1. can contain more information on the position of each type of detector (it seems a black box, in the present presentation). A separation of the figure caption on the work text is necessary, too.	I try to give a better explanation.
A short explanation of the connection between the modification of the angular acceptance and energies of the incoming particles is necessary.  There are some difficulties in the understanding of the neutrino search. Some references could help here. Some details and references on simulations and predictions based on these simulations are useful in the third and fourth pages.	References and details have been inserted.
A correction in the second proposition from the row 107 is useful, too.	I made the requested change.

Thank you, I am available for any further comments.

Beatrice Panico