Muon Radiography Method for Non-Invasive Probing an Archaeological Site in the Naryn-Kala Citadel

Round 1

Reviewer 1 Report

The paper is well written, interesting to read, and reports on an original measurement. The authors have placed several emulsion plates within an underground construction of the Naryn-Kala fortress, aiming at revealing the structure of/behind the walls. Definitely, muon imaging is a very appropriate, non invasive technique in this configuration.

The authors performed Geant4 simulations to evaluate different scenarios of thicknesses and densities. The choice of the muon detector (nuclear emulsions) was apparently driven by its availability, spatial resolution, easy operation and scanning equipment at hand. However, the spatial resolution was not needed in this case, as the images and analysis seem to be limited by the statistics. More importantly, the emulsions apparently strongly suffered from the environmental conditions. Looking at Figure 5, it is questionable whether a muography from such emulsions can give relevant/precise information. However, as I understand, it is a first trial, and this work should definitely be encouraged and continued.

I list below some questions/comments of various importance for the authors:

- line 46-49: the pyramid should be named consistently (Khufu or Cheops)

- line 134: the 2 should be a square

- Figure 4: could you please explain the muon deficit around ty = -0.5?

- Figure 6 really does not look like the simulations presented on Figure 4, and this should be commented. In particular, why has it a circular shape, with a hole at the center? The maximum of muon is obtained around ty -0.5, i.e. at the place of the muon deficit in the simulation.

- related to the previous comment, I think the statement of lines 199-200 is hard to justify

- the authors mentionned 5 plates used for this experiment, but only one is presented in the paper, does it mean the others were not usable?

- line 207: the study the -> the study of the

To conclude, I think that if these questions/comments are properly addressed, this paper should definitely be published.

Author Response

Dear colleague,

thank you very much for useful remarks and comments!

In attached file our answers for your remarks/

Best regards - Natalia Polukhina

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper describes a preliminary study for a muon radiography of a building in the Naryn-Kala citadel. The method described follows the famous Khufu's Pyramid discovery (well cited), which lead to the finding of a large void gallery inside the pyramids. However, the proposed paper is a first attempt  of employing this method and no clear findings are presented.

Still it is possible to publish the results as "proof of concept" and simulation studies, but results from the data taking are very vague.  

- a picture of the detector could be added 

- more details on the spatial resolution of the emulsion plates used would be advisable

- missing explanation about the handling of the emulsion (have the emulsions been transported by plane? have backgound tracks been rejected?). No humidity or temperature protection protections: whoch effect can they have on the measurement?

- l. 122 and following: better specify the source of "estimates"

- Muon decays has been taken into account?

- cuts on the angular range of muons have been applied?

- l.199: the similarity to the simulation variant (b) is not so clear to the average reader: a better quantification would improve the scientific soundness of the paper.

- possibly go into details of the plans for future measurements  

Author Response

Dear colleague,

thank you very much for useful remarks and questions!

In attached file our answers for your remarks.

Best regards - Natalia Polukhina

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I thank the authors for their detailed comments and answers to my 1st review. I think the paper should now be published. I just noticed a few typos on the added text:

-l 177: is to do -> has to do

- l 212: 2 dots after shifted

- l 212: "c" after ty>0

- l 212: indicate -> indicates

I'm impatient to see more about this research!

Author Response

Dear colleague,

thanks a lot for your remarks and comments! Best regards - Natalia Polukhina

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

     the ideas behind the "Muon radiography method for non-invasive probing an archaeological site in the Naryn-Kala citadel " are good and extensive simulation of the results have been carried out. The measurements themselves are very preliminary (ruined by bad quality of the detector and not by lack of knowledge from the authors). I would recommend the publication of the paper to allow further studies. 

Author Response

Dear colleague,

thanks a lot for your support! Best regards - Natalia Polukhina