The Neutrino Mediterranean Observatory Laser Beacon: Design and Qualification

Round 1

Reviewer 1 Report

I have reviewed the manuscript submitted by Diego Real et al., titled "The NEMO Laser Beacon: Design and Qualification."

Upon reviewing the content, I find that the manuscript requires a comprehensive revision, and in some cases, it might be beneficial to consider rewriting it from scratch.

The Abstract primarily consists of introductory sentences and lacks a clear description of the paper's content. The last sentence, "This paper encapsulates details of the laser beacon’s design, offering a profound contribution to the field of the time calibration of underwater neutrino telescopes," is relevant but should be positioned at the beginning. The abstract should further elaborate on the specific contributions and findings of the paper.

The opening paragraph of the manuscript appears to be copied directly from the internet without proper rephrasing. While the overall similarity might be within permissible limits, this paragraph appears to be largely copied from a single source and needs to be rephrased.

Additionally, the conclusion section lacks a scientific approach. Throughout the conclusion, the authors repeatedly use terms like "elaborated," "examined," "elucidated," "highlighted," and "detailed," without clearly describing the actual accomplishments of the study.

In summary, I recommend a thorough revision of the manuscript, with particular attention to improving the clarity and scientific rigor of the abstract, introduction, and conclusion sections. It might be beneficial to rephrase and rewrite the content where necessary to ensure a clear and coherent presentation of the study's objectives, methods, and findings.

Author Response

Upon reviewing the content, I find that the manuscript requires a comprehensive revision, and in some cases, it might be beneficial to consider rewriting it from scratch.

The Abstract primarily consists of introductory sentences and lacks a clear description of the paper's content. 

The last sentence, "This paper encapsulates details of the laser beacon’s design, offering a profound contribution to the field of the time calibration of underwater neutrino telescopes," is relevant but should be positioned at the beginning. 

Done

 The abstract should further elaborate on the specific contributions and findings of the paper.

The abstract has been redone

The opening paragraph of the manuscript appears to be copied directly from the internet without proper rephrasing. While the overall similarity might be within permissible limits, this paragraph appears to be largely copied from a single source and needs to be rephrased.

The first paragraph has been redone and has been complemented with an additional paragraph about neutrino telescope gime calibration.

Additionally, the conclusion section lacks a scientific approach. Throughout the conclusion, the authors repeatedly use terms like "elaborated," "examined," "elucidated," "highlighted," and "detailed," without clearly describing the actual accomplishments of the study.

The conclusions have been redone.

In summary, I recommend a thorough revision of the manuscript, with particular attention to improving the clarity and scientific rigor of the abstract, introduction, and conclusion sections.

 It might be beneficial to rephrase and rewrite the content where necessary to ensure a clear and coherent presentation of the study's objectives, methods, and findings.

Abstract, introduction and conclusions have been redone

Reviewer 2 Report

Paper is suitable for publication. All information is clearly described with citations. There are two missing pieces of information. The first are detailed diagrams of the beacon in Section 1 (overview), 2 (design), 6 (angle min and max), and maybe electronics diagrams if you have them for Section 9 (electronics). I think all that is required is labeling Figure 1 (left) and Figures 4-6 at the minimum.   The second is a detailed description of how the beacon improves the point accuracy from both an intra and inter method. The ANTARES beacon is referenced but no motivation provided on why this beacon is better for inter and intra calibration and how that calibration improves point accuracy and NEMO measurements for a general reader. If the beacon's predicted or actual performance is not known and this would be too much to request, you could delete areas in which "improvement" are in Section 1 and the conclusion (line 401) but that is up to you.     Full Comments

• Sections 1 and 2: Are there NEMO official plots that can be shown and described to motivate the needs of intra-string and inter-string calibration? I ask because I have a hard time understanding why this is an improvement to the ANTARES system and what physics benefits it provides. Even a diagram on Line 52 would help me "see" why ANTARES cannot do this and what this beacon can.
• Why are things painted red? I read that a couple times and was curious. I assumed it has something to do with locating the beacon, biofouling, or laser constraints but it would be good to say why it was painted red? Am I just being silly?
• Line 48 (Proofreading): , expected to exceed . . . attenuation lengths,
• LIne 64 (Proofreading): The laser
• Line 81 (Formatting and Substance): The two bullet lists appear to be together. Could you maybe break them up a little more? A figure would be nice labeling each component in the beacon, similar to image in the left side of Figure 1.
• Line 112 (Proofreading): "it is"
• Line 115 (Proofreading): "of"->"from"
• Figure 2: Can you change the x-axis to "Available". Suministred, I believe is Spanish for supplied, but it is confusing because isn't 1.4 V the total supplied voltage when 100% of battery charge is available.
• Line 121: nominal voltage
• Line 122: "when it is fully charged"
• Line 124: " necessary. Considering that the temperature . . . , the criterion should be met when deployed."
• Line 147: validates->validate
• Line 190: quotations not necessary for the variables, either use () or mathmode, as what is used in the equaitons. Could you also list the equations in LaTeX and reference them?
• Figure 4: Faded and hard to read. Is it 1.1472 for n' and the way the angles are written is in minutes. Can it be degrees? Can you label all the components? Could Figure 5 and 6 have its rectangles labeled too?
• Table 2: Possible typo for elongation where it says "14"
• Section 8 very hard to see without a diagram. The proposed diagram in comment on Line 81 could be moved here?
• Figure 7: "Glass rod next to the top tap . . "
• Line 241: "for the optical attenuator"
• Line 280: Can these be numbered equations so they can be referenced?
• Line 313: "Laser"->"laser"
• Line 331: "initiates"->"starts operation" I do not understand if this means it starts operation or
• Define "fuse" on line 331, you did at line 339 after using it three times.
• Line 352: Quotations both closed, make one open in LaTeX, check this for all other quotations like line 357
• Line 361 Standby in italics but Analyze Command in quotations. What is the difference between the two are the modes different than the functions?
• See above for line 364-366
• Line 391 Qualification
• Line 401: I do not think that has been highlighted sufficiently. Was there some number or plot I missed? The only mention is to the already existing literature from DUMAND, Amanda, etc.

The proofreading errors are included above. The only one that I found hard to understand was the x-axis label on Figure 2. I would prefer the term "Battery Charge Remaining" or "Available Charge" or "Available Capacity" to the current phrase "Suministred Capacity."

Author Response

Paper is suitable for publication. All information is clearly described with citations. There are two missing pieces of information. The first are detailed diagrams of the beacon in Section 1 (overview), 2 (design), 6 (angle min and max), and maybe electronics diagrams if you have them for Section 9 (electronics). I think all that is required is labeling Figure 1 (left) and Figures 4-6 at the minimum. 

 

The labelling of Figure 1 (right and left), 4,5 and 6 has been done. Indeed Figures 4 and 6 have been redone.

  The second is a detailed description of how the beacon improves the point accuracy from both an intra and inter method. The ANTARES beacon is referenced but no motivation provided on why this beacon is better for inter and intra calibration and how that calibration improves point accuracy and NEMO measurements for a general reader. If the beacon's predicted or actual performance is not known and this would be too much to request, you could delete areas in which "improvement" are in Section 1 and the conclusion (line 401) but that is up to you.    

 

Indeed the laser is more appropriate for inter-line calibration (although it can help in inter-line calibration). The improvement in the calibration process (compared to Antares) is because the lase is more powerful and the light can be tuned (so similar amounts of light can be used for the inter-line calibration process. This has been clarified in the text.

 

 Full Comments

• Sections 1 and 2: Are there NEMO official plots that can be shown and described to motivate the needs of intra-string and inter-string calibration? I ask because I have a hard time understanding why this is an improvement to the ANTARES system and what physics benefits it provides. Even a diagram on Line 52 would help me "see" why ANTARES cannot do this and what this beacon can do.
•  
• There are no official plots from Nemo. The laser proposed for NEMO improves the one used in ANTARES [ref 12] because the light is more intense and it can be tuned (in addition to the battery system that improves the portability) so similar amounts of light can arrive at storeys located at different distances. This improves the inter-line calibration process. Figure 5 helps explain this. Also, some additional clarification has been added:

“This configuration allows the laser to perform inter-string calibration effectively, especially by allowing to illuminate optical modules of different lines with a similar amount of light.”

Also, some errata about inter and intra-calibration have been corrected

•  

• Why are things painted red? I read that a couple of times and was curious. I assumed it has something to do with locating the beacon, biofouling, or laser constraints but it would be good to say why it was painted red? Am I just being silly?

• This is explained in line 230: “This cover, painted in red, serves the dual purpose of enhancing visibility and mandating its removal prior to deployment. “

• The caption of Figure 1 has been expanded to better clarify: “which is protected by a PCB cap painted in red. It serves as a warning for its removal before deployment.”

            

• Line 48 (Proofreading): , expected to exceed . . . attenuation lengths,

                  , which would exceed 3 attenuation lengths,

• LIne 64 (Proofreading): The laser

                The laser beacon provides a solution to generate high-intensity pulses…

• Line 81 (Formatting and Substance): The two bullet lists appear to be together. Could you maybe break them up a little more?

• Done

•  
• A figure would be nice labeling each component in the beacon, similar to image in the left side of Figure 1.
•   Done
• Line 112 (Proofreading): "it is"

• Done

• Also: if it’s off while turns -> if it is off while turns ( in line 366)

• Line 115 (Proofreading): "of"->"from"

• Done

•  
• Figure 2: Can you change the x-axis to "Available". Suministred, I believe is Spanish for supplied, but it is confusing because isn't 1.4 V the total supplied voltage when 100% of battery charge is available.

            Done

• Line 121: nominal voltage

             Done

• Line 122: "when it is fully charged"

• Done

• Line 124: " necessary. Considering that the temperature . . . , the criterion should be met when deployed."
• Done
• Line 147: validates->validate
• Done
• Line 190: quotations not necessary for the variables, either use () or mathmode, as what is used in the equaitons. Could you also list the equations in LaTeX and reference them?

             Modified to mathmode and added numbers to equations.

• Figure 4: Faded and hard to read. Is it 1.1472 for n' and the way the angles are written is in minutes. Can it be degrees? 

• The n is the refractive index. The units of the angle of the figure is not specified (in the text is in degrees)

• Can you label all the components? Could Figure 5 and 6 have its rectangles labeled too? Done. Figure 5 exemplifies why this beacon improves the one from Antares. In addition to the battery system that enhances the portability, the level of light can be adjusted to illuminate the different storeys with the same level of light.
• Table 2: Possible typo for elongation where it says "14”

• Done: 14% -> %

• Section 8 very hard to see without a diagram. The proposed diagram in comment on Line 81 could be moved here?

• A reference to figure 1 has been added. Also it has been added the reference to Figure 7.

• Figure 7: "Glass rod next to the top tap . . "
• Done: “Glass rod next to the top cap”
• Line 241: "for the optical attenuator"

• Done

• Line 280: Can these be numbered equations so they can be referenced?

             Done

• Line 313: "Laser"->"laser"
• Done
• Line 331: "initiates"->"starts operation" I do not understand if this means it starts operation or
• Done
• Define "fuse" on line 331, you did at line 339 after using it three times.

• Done

• Line 352: Quotations both closed, make one open in LaTeX, check this for all other quotations like line 357
• Done
•  
• Line 361 Standby in italics but Analyze Command in quotations.
• Done
•  What is the difference between the two are the modes different than the functions?

• Yes, this is why the functions are in quotations and the modes in italics.

• See above for line 364-366

• The modes have been set to italics

• Line 391 Qualification
• Modified to “Lase beacon qualification”
• Line 401: I do not think that has been highlighted sufficiently. Was there some number or plot I missed? The only mention is to the existing literature from DUMAND, Amanda, etc.

• Additional text has been added in the intro:

•  

• Neutrino telescopes employ large volumes of ice or water to detect Cherenkov light from neutrino interactions. These detection systems incorporate arrays of photomultipliers, organized in lines or towers. Ensuring precise synchronization of these photomultipliers is imperative for accurate Cherenkov light identification and timing measurements. While a primary clock signal is distributed to nodes for synchronization purposes, its effectiveness can be hindered by signal deviations and limited range. Consequently, in-situ calibration techniques, such as leveraging downgoing muons, exploiting radioactive Potassium-40 emissions, or employing pulsed light sources with 1 ns precision, become indispensable for achieving synchronization and precise measurements.

 

Round 2

Reviewer 1 Report

The authors have made important improvements to the manuscript, and it now seems suitable for publication.

Author Response

Thanks for the review

Reviewer 2 Report

Change figure 1 left, so the caption "Laser control board" is moved to the left and no longer covered by the device.

See previous report.

Author Response

 

 

 The label of Figure 1 left: "Laser control board" has been moved to the left and the document has been proofread.