Simulations of the EAS Development in the Atmosphere and Detectors for Experiments with the High-Altitude Ionization Calorimeter ADRON-55

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper describes the development of the Monte Carlo simulation of the performance of ADRON-55 calorimeter. The first part describes the development of the package that simulates the EAS, whereas the second part focus on the ADRON-55 expected performance.

I have several questions and comments about the paper:

The title is partially misleading. The main part of the article focus on the development of the EAS simulation more than on the calorimeter response. The same issue can be detected on the introduction, that focuses 100% on the EAS simulations and provides no scientific background about the importance and interest of the subject. 

In the first part, there is not a real description of the development of the simulation, and the choice of the energies for which results are shown is not explained. Also thresholds set on simulation are not explained or justified.

In the last part, the description of the detector and of the simulation structure is not detailed much. Results are not sufficient to give the reader an idea of the performance of the detector and are not compared with other projects and experiments with the same scientific target.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The english is acceptable, but the review of a native speaker would improve significantly the quality of the work.

Author Response

1. Reviewer: The title is partially misleading. The main part of the article focus on the development of the EAS simulation more than on the calorimeter response. The same issue can be detected on the introduction, that focuses 100% on the EAS simulations and provides no scientific background about the importance and interest of the subject. 

Answer:

Obviously, to compare the simulation results and experimental data on EAS characteristics, it is necessary to simulate the passage of hadrons and electromagnetic particles of EAS through the calorimeter. The corresponding calculations for the BIC calorimeter [1-- 5] were carried out using very primitive programs, which did not allow a detailed analysis of the experimental data. At present, it is possible to model processes in a hadron calorimeter using the modern Geant4 package.
(inserted into the article, last paragraph of the Introduction)

2. Reviewer: In the first part, there is not a real description of the development of the simulation, and the choice of the energies for which results are shown is not explained. Also thresholds set on simulation are not explained or justified.

Answer:

We started with the simplest case, i.e. simulation of vertical events because of easy interpretation of their behavior in the calorimeter. Energy range 1-100 PeV which is the most actual for experimental data interpretation was used. These thresholds are chosen for EAS simulations with CORSIKA. They are definitely lower than can be attributed to the calorimeter. While tracking the shower particles through ADRON-55 with Geant4 the electron threshold was made higher (50 MeV) insuring that the deposited energy distribution inside the calorimeter did not change after the rise.

3. Reviewer: In the last part, the description of the detector and of the simulation structure is not detailed much. Results are not sufficient to give the reader an idea of the performance of the detector and are not compared with other projects and experiments with the same scientific target.

Answer:

There is no an experiment with the same scientific target in the world, strictly speaking. The performance of the detector is still not clear to the authors, we are in the very beginning of the road to knowing the calorimeter capabilities.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have done an excellent simulation of the ADRON-55 detector. However, the paper's final statement is, “The calculated results are very preliminary.” If true, shouldn’t the authors wait until the simulation is final?

Upon reading the paper, I have several suggestions:

a)        The abstract starts by saying, “EAS cores.”  The paper indeed discusses what that means early in the paper.  It would benefit non-expert readers to discuss briefly what it is in the abstract.

b)        Given the paper's focus on the ADRON-55 calorimeter, it would greatly enhance the reader's understanding and engagement if a diagram of this crucial component were included.

c)         A strangelet is a very undefined term.  It is naively matter with strange quarks.  That is a very general term.  The authors need to define their model to study the effects of stangelets.

d)        The authors have presented detailed Monte Carlo studies, which is commendable. However, it's essential for them to clearly outline the methods used to verify the accuracy of these results. This will instill a sense of trust and security in the reader regarding the reliability of the findings.

e)        It would be beneficial if the version number of Geant4 and other Monte Carlo codes were specified in the paper.

f)           Discussing how well the authors could detect strangelets with their detector would be a useful topic to present.

Author Response

Comments and Suggestions for Authors

The authors have done an excellent simulation of the ADRON-55 detector. However, the paper's final statement is, “The calculated results are very preliminary.” If true, shouldn’t the authors wait until the simulation is final?

Answer:

The preliminary nature of the results meant that at this stage the results of modeling the passage of individual particles of different types through the ADRON-55 detector were analyzed. The authors consider the expression used to be inappropriate. It has been removed from the text of the article.

Upon reading the paper, I have several suggestions:

Reviewer:

1. a)        The abstract starts by saying, “EAS cores.”  The paper indeed discusses what that means early in the paper.  It would benefit non-expert readers to discuss briefly what it is in the abstract.

Answer:

It's done

Reviewer:

1. b)        Given the paper's focus on the ADRON-55 calorimeter, it would greatly enhance the reader's understanding and engagement if a diagram of this crucial component were included.

Answer:

It's done  (see Fig.1)

Reviewer:

1. c)         A strangelet is a very undefined term.  It is naively matter with strange quarks.  That is a very general term.  The authors need to define their model to study the effects of stangelets.

Answer:

Indeed, the model of strangelet interactions used, described in Section 3.2, is very naive, a kind of zero approximation. The authors are currently developing a new model of strangelet interactions that differs from the interactions in the quasi-nuclear model.

Reviewer:

1. d)        The authors have presented detailed Monte Carlo studies, which is commendable. However, it's essential for them to clearly outline the methods used to verify the accuracy of these results. This will instill a sense of trust and security in the reader regarding the reliability of the findings.

Answer:

We use well-known and widely used codes, shown plots and graphs indicate reasonable behavior of particle tracks and spectra in accordance with the laws of physics. These are the methods we use to verify the accuracy of these results.

Reviewer:

1. e)        It would be beneficial if the version number of Geant4 and other Monte Carlo codes were specified in the paper.

Answer:

Already done.

Reviewer:

1. f)           Discussing how well the authors could detect strangelets with their detector would be a useful topic to present.

Answer:

Clearly, distinguishing showers initiated by hypothetical strangelets and traditional cosmic ray primary particles is a difficult task. We plan to seek ways to address this issue by exploring the combination of information that can be obtained from the characteristics of the hadron and electron-positron components, in particular from the longitudinal development of hadron cascades deep in the calorimeter, as well as from the lateral distribution of charged particles.
(inserted into the article, the last paragraph of section 3.2.2)

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is devoted to a numerical modeling of extensive air shower (EAS) development, for various types of primary particles, and of the corresponding signal in a high altitude hadronic calorimeter.

The presented study is interesting and can be accepted for publication, after a suitable revision.


Queries and remarks.

1. The presented results seem to demonstrate that discriminating hypothetical strangelets from usual cosmic ray primaries should be a difficult task. The authors may consider to comment on that point.

2. The superposition model is expected to work rather well for nucleus-induced EAS, which is a direct consequence of the Glauber geometry for nucleus-nucleus interactions. I.e., average characteristics of EAS initiated by primary nucleus of mass number $A$ can be approximated by the ones of $A$ proton-induced showers, of $A$ times smaller energy. It may be of interest to check how well this works for the energy spectra and lateral distributions of hadrons, presented in Figs. 1 and 2, and how large are deviations from the superposition model for the chosen treatment of strangelet interactions.

3. Since hadron component of EAS is highly stochastic, in addition to average characteristics presented in the manuscript, it is advisable to study the corresponding fluctuations, e.g., a distribution of the number of hadrons, above a certain energy threshold.

4. In Figs. 12c and 12d, the iron signal in all the scintillator layers is systematically lower, compared to the proton case, which is consistent with results presented in Figs. 1-5. However, this is not the case for Figs. 12a and 12b, where one observes a deeper 'penetration' of iron-induced cascades: there is no suppression in the last 2-3 layers of the calorimeter. A similar behavior is observed in the case of strangelets (Fig. 13). This requires additional clarifications.

Comments on the Quality of English Language

1) Since experimental measurements are not discussed in the manuscript, the last sentence of the abstract ('...based on data from...') should be rephrased. For example, like '...related to measurements with...

2) Last paragraph at page 1, 1st sentence.
'In the last tens of years ago in the...' -> 'In the last tens of years the...'

3) Last sentence in section 2.1: add a bracket after 'etc.'.

4) The 2nd and 3rd paragraphs at page 5 are identical to each other.

5) 1st paragraph at page 8, 2nd sentence:
'This is expressed in the fact...' -> This reflects the fact...'

Author Response

Reviewer: 1. The presented results seem to demonstrate that discriminating hypothetical strangelets from usual cosmic ray primaries should be a difficult task. The authors may consider to comment on that point.
Answer:

Clearly, distinguishing showers initiated by hypothetical strangelets and traditional cosmic-ray particles is a difficult task. We plan to seek ways to address this issue by exploring the combination of information that can be obtained from the characteristics of the hadron and electron-positron components, in particular from the longitudinal development of hadron cascades deep in the calorimeter, as well as from the lateral distribution of charged particles.
(inserted into the article, the last paragraph of section 3.2.2)

Reviewer: 2. The superposition model is expected to work rather well for nucleus-induced EAS, which is a direct consequence of the Glauber geometry for nucleus-nucleus interactions. I.e., average characteristics of EAS initiated by primary nucleus of mass number $A$ can be approximated by the ones of $A$ proton-induced showers, of $A$ times smaller energy. It may be of interest to check how well this works for the energy spectra and lateral distributions of hadrons, presented in Figs. 1 and 2, and how large are deviations from the superposition model for the chosen treatment of strangelet interactions.
Answer:

We plan to do this in the future, in particular, we are currently developing a new model for strangelet interactions

Reviewer: 3. Since hadron component of EAS is highly stochastic, in addition to average characteristics presented in the manuscript, it is advisable to study the corresponding fluctuations, e.g., a distribution of the number of hadrons, above a certain energy threshold.
Answer:

The authors fully agree that it is advisable to study fluctuations in the distribution of the number of hadrons, as well as other fluctuations, such as spatial and energetic ones. We plan to do this in the nearest future.

Reviewer: 4. In Figs. 12c and 12d, the iron signal in all the scintillator layers is systematically lower, compared to the proton case, which is consistent with results presented in Figs. 1-5. However, this is not the case for Figs. 12a and 12b, where one observes a deeper 'penetration' of iron-induced cascades: there is no suppression in the last 2-3 layers of the calorimeter. A similar behavior is observed in the case of strangelets (Fig. 13). This requires additional clarifications.

Answer:

13a: proton 1 PeV; 13b: iron nucleus; 13c: proton 100 PeV; 13d: iron nucleus 100 PeV.  Iron nuclei always give lower ionization compared to protons. What else can we conclude using only a few profiles?
As for Figs. 14a and 14b, obtained for two different strangelet-initiated showers, they show that fluctuations in such showers are very small.

 

Reviewer: Comments on the Quality of English Language

1) Since experimental measurements are not discussed in the manuscript, the last sentence of the abstract ('...based on data from...') should be rephrased. For example, like '...related to measurements with...
Answer:

It is corrected

2) Last paragraph at page 1, 1st sentence.
'In the last tens of years ago in the...' -> 'In the last tens of years the...'
Answer:

It is corrected

3) Last sentence in section 2.1: add a bracket after 'etc.'.
Answer:

It is corrected

4) The 2nd and 3rd paragraphs at page 5 are identical to each other.
Answer:

It is corrected

5) 1st paragraph at page 8, 2nd sentence:
'This is expressed in the fact...' -> This reflects the fact...'

Answer:

It is corrected

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors addressed all the comments and their answers are implemented in the text. I have no more comment for them.

Author Response

• Page 2 --- (Fig. 1 in Ref. [7])

Ester Ricci -  Can you add the figure there? It is quite important to understand the detector structure and it is really unconvenient to have to search the figure elsewhere.

 

Answer: Added to the article -- Figure 1. Cross section of the “ADRON-55” calorimeter.

___________________________________________________________________________

• Page 3. The QGSJET II-04 [9-12] model of hadronic interactions was accepted as the basic one.

Ester Ricci - Page 3.1 --- What is the reason to choose this model? Do you compared more models and their performances?

Answer: The model is well established and kept up to date using accelerator and cosmic ray data. It is used by many colleagues for years. We also use it widely but plan to involve also SIBYLL and EPOS into simulations. At the moment, we don't need them, since we are at the very beginning of studying the ADRON-55 calorimeter and are more interested in studying its capabilities than in the differences in the behavior of the interaction models that it can reveal.

• Page 3.1 The following energy thresholds were used: 1 GeV for hadrons and muons, and 30 MeV for electromagnetic particles (e±, γ).

 

Ester Ricci - Page 3.1 --- How have these thresholds been selected? Does they come from hardware properties

Answer:

These thresholds have been chosen for EAS simulations with CORSIKA. They are definitely lower than can be attributed to the calorimeter. While tracking the shower particles through ADRON-55 with Geant4 the electron threshold was made higher (50 MeV) insuring that the deposited energy distribution inside the calorimeter did not change after the rise.

___________________________________________________________________________

• Page 3.2 --- Modeling of the development of EASs from the so-called strangelets – stable particles of strange quark matter (SQM).

 

Ester Ricci - Page 3.2 --- This sentence looks incomplete.

Answer: 

This error is corrected and the sentence is completed as follows:

Modeling of the development of EASs from the so-called strangelets – stable particles of strange quark matter (SQM) – has begun.

___________________________________________________________________________

• Page 3.2 --- 1, 4, 12, 32, 56 (i.e. protons, He, C, S, Fe).

Ester Ricci   --- Units!!!

Answer:

This error is corrected: the term  a.m.u.” (“atomic mass unit) is used as follows:

“…, which can then form a nucleus (or several nuclei) with masses of 1, 4, 12, 32, 56 a.m.u. (i.e. p, He, C, S, Fe)”

 

___________________________________________________________________________

• Page 3.2 --- The energy thresholds are taken to be 30 MeV for electromagnetic particles (e± and γ-rays) and 1 GeV for muons and hadrons.

Ester Ricci   ---  Again, how do you set this threshold? 
Answer:

Please, see Answer in the point 3) Page 3.1  

___________________________________________________________________________

• Page 3.2.2 --- Since the dimensions of the “ADRON-55” calorimeter are ~8×7 m², EAS characteristics near the core are primarily of interest. Properties of showers initiated by different primary particles at the same energy E0 differ most strongly in this region. All the simu-lation results presented below were obtained for the central region, i.e. at distances R to the EAS axis of less than 10 m.

Ester Ricci   ---  How many events of this type can we expect in one year? 

Answer: We expect ~1500 EASs with E₀ > 1 PeV per one year

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

1. Please clarify "Ionization profiles of protons exceed the profiles of ion nuclei of the same primary energy, the later exceed the profiles of stranglets.".  It is not clear what the word "exceed" means. This sentence needs more explanation.

2.  Describe the model of strangelets used in Ref. 7 in a few sentences.

3. I suggest putting the data from 13 a and 13 b on the same plot. It would be easier for the reader to compare them. I have the same suggestion for 13 c and 13 d and 14 a and 14 b.

Comments on the Quality of English Language

The English is acceptable.  There is a problem with the formatting for Reference 4.

Author Response

Comment 1: Page 2 --- (Fig. 1 in Ref. [7])

Ester Ricci -  Can you add the figure there? It is quite important to understand the detector structure and it is really unconvenient to have to search the figure elsewhere.

Answer: Added to the article -- Figure 1. Cross section of the “ADRON-55” calorimeter.

___________________________________________________________________________

Comment 2: Page 3. The QGSJET II-04 [9-12] model of hadronic interactions was accepted as the basic one.

Ester Ricci - Page 3.1 --- What is the reason to choose this model? Do you compared more models and their performances?

Answer: The model is well established and kept up to date using accelerator and cosmic ray data. It is used by many colleagues for years. We also use it widely but plan to involve also SIBYLL and EPOS into simulations. At the moment, we don't need them, since we are at the very beginning of studying the ADRON-55 calorimeter and are more interested in studying its capabilities than in the differences in the behavior of the interaction models that it can reveal.

Comment 3: Page 3.1 The following energy thresholds were used: 1 GeV for hadrons and muons, and 30 MeV for electromagnetic particles (e±, γ).

Ester Ricci - Page 3.1 --- How have these thresholds been selected? Does they come from hardware properties

Answer:

These thresholds have been chosen for EAS simulations with CORSIKA. They are definitely lower than can be attributed to the calorimeter. While tracking the shower particles through ADRON-55 with Geant4 the electron threshold was made higher (50 MeV) insuring that the deposited energy distribution inside the calorimeter did not change after the rise.

___________________________________________________________________________

Comment 4: Page 3.2 --- Modeling of the development of EASs from the so-called strangelets – stable particles of strange quark matter (SQM).

Ester Ricci - Page 3.2 --- This sentence looks incomplete.

Answer: 

This error is corrected and the sentence is completed as follows:

Modeling of the development of EASs from the so-called strangelets – stable particles of strange quark matter (SQM) – has begun.

___________________________________________________________________________

Comment 5: Page 3.2 --- 1, 4, 12, 32, 56 (i.e. protons, He, C, S, Fe).

Ester Ricci   --- Units!!!

Answer:

This error is corrected: the term  a.m.u.” (“atomic mass unit) is used as follows:

“…, which can then form a nucleus (or several nuclei) with masses of 1, 4, 12, 32, 56 a.m.u. (i.e. p, He, C, S, Fe)”

___________________________________________________________________________

Comment 6: Page 3.2 --- The energy thresholds are taken to be 30 MeV for electromagnetic particles (e± and γ-rays) and 1 GeV for muons and hadrons.

Ester Ricci   ---  Again, how do you set this threshold? 
Answer:

Please, see Answer in the point 3) Page 3.1 

___________________________________________________________________________

Comment 7: Page 3.2.2 --- Since the dimensions of the “ADRON-55” calorimeter are ~8×7 m², EAS characteristics near the core are primarily of interest. Properties of showers initiated by different primary particles at the same energy E0 differ most strongly in this region. All the simu-lation results presented below were obtained for the central region, i.e. at distances R to the EAS axis of less than 10 m.

Ester Ricci   ---  How many events of this type can we expect in one year? 

Answer:

We expect ~1500 EASs with E₀ > 1 PeV per one year

Author Response File: Author Response.pdf