Measurements of Decoherence in Small Sea-Level Extensive Air Showers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The submitted paper considers known effect of air-shower decoherence. Despite of educational impact of the study, its scientific significance is at rather low lower. The author does not provide quantitative results, and does not compare them with previous ones.

The paper can be published only after elaboration of conclusion with clear numerical output and comparison with existing results showing the novelty of the result.

Other minor comments:

* The LaTeX formulas and special symbols should be properly formatted

* Fig. 1 and 2 show the same, could be either combined, or Fig. 2 can be simply removed

 

Author Response

The submitted paper considers known effect of air-shower decoherence. Despite of educational impact of the study, its scientific significance is at rather low lower. The author does not provide quantitative results, and does not compare them with previous ones.

The paper can be published only after elaboration of conclusion with clear numerical output and comparison with existing results showing the novelty of the result.

Other minor comments:

* The LaTeX formulas and special symbols should be properly formatted

• Fig. 1 and 2 show the same, could be either combined, or Fig. 2 can be simply removed

I thank the reviewer for carefully reading the manuscript.  The paper includes numerical values of decoherence scale lengths and the Discussion and Conclusions have been modified to discuss those values in comparison to the limited data in the literature.

Figures 2 and 3 (not 1 nd 2?) do contain the same data but the former is expressed in the usual way and the other is to lead into the discussion later in the paper.  I have left both Figures in to aid the reader.

The paper was prepared using the Universe Word template so LaTex symbols were not used.

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript outlines and evaluates some design features of instruments built to detect and measure cosmic-ray-induced extensive air showers near sea level. Such instruments often are built as arrays of detectors, some of which can be triggered by a given air shower event  with the air shower "measurements" dependent, in part on "coincident triggering of detectors. Nominally, detector triggering and subsequently derived air shower information depends on the location of a given detector within the air shower. On the other hand coincident detector triggering also depends on instrument function in several ways. The manuscript focuses specifically on information (both real and bogus) derived from pairs of triggered detectors and especially on triggered detector separation and size. A key point of the study presented is improved reliability of triggering behaviors when the triggering involves both the specific detectors themselves and signal from an external shower detector. While, I am familiar with the basic physics of extensive air showers and their detection by instruments such as those discussed in this manuscript, my cosmic ray related research concentrates on theoretical issues associated with the acceleration and transport of cosmic rays in astrophysical contexts. I will say that the instrumental issues dealt with in the manuscript are obviously important to understand in order to understand the information the instruments provide and that the design of the study presented in the manuscript seems solid.  There are, however, specific presentation issues that need to be addressed in order for the manuscript to be acceptable for publication in Universe.

Most notable is that the term ""Shower Size Parameter:" is used extensively as a dimensionless number, but is not clearly defined. At its introduction in section 2.2.1 there is a general statement that it is related to the total number of detected particles. On the other hand, Figure 1 plots the total number of detected particles vs this parameter. This would seem to contradict the previous statement. This confusion weakens much of the subsequent presentation of the study.

 

Author Response

This manuscript outlines and evaluates some design features of instruments built to detect and measure cosmic-ray-induced extensive air showers near sea level. Such instruments often are built as arrays of detectors, some of which can be triggered by a given air shower event  with the air shower "measurements" dependent, in part on "coincident triggering of detectors. Nominally, detector triggering and subsequently derived air shower information depends on the location of a given detector within the air shower. On the other hand coincident detector triggering also depends on instrument function in several ways. The manuscript focuses specifically on information (both real and bogus) derived from pairs of triggered detectors and especially on triggered detector separation and size. A key point of the study presented is improved reliability of triggering behaviors when the triggering involves both the specific detectors themselves and signal from an external shower detector. While, I am familiar with the basic physics of extensive air showers and their detection by instruments such as those discussed in this manuscript, my cosmic ray related research concentrates on theoretical issues associated with the acceleration and transport of cosmic rays in astrophysical contexts. I will say that the instrumental issues dealt with in the manuscript are obviously important to understand in order to understand the information the instruments provide and that the design of the study presented in the manuscript seems solid.  There are, however, specific presentation issues that need to be addressed in order for the manuscript to be acceptable for publication in Universe.

Most notable is that the term ""Shower Size Parameter:" is used extensively as a dimensionless number, but is not clearly defined. At its introduction in section 2.2.1 there is a general statement that it is related to the total number of detected particles. On the other hand, Figure 1 plots the total number of detected particles vs this parameter. This would seem to contradict the previous statement. This confusion weakens much of the subsequent presentation of the study.

I thank the reviewer for carefully reading the manuscript and considering the experimental issues in the paper.

I have added further comments on the use of the wording "Shower Size Parameter".  This wording is used because of the small size of the Roof Array.  Workers used to larger arrays would not be particularly used to some bias issues found with very small arrays.  However, it is pointed out that this parameter is close to the familiar 'shower size'.  For some instances relevant to their work Figs 11-13 and the toy model, a simple shower size was retained since that would be familiar.  Figure 1 shows the distribution of this parameter and the caption notes its closeness to a shower particle size.

Reviewer 3 Report

Comments and Suggestions for Authors

The paper is well written and I only have a few minor comments.

1. Line 102, font -> front?
2. Line 111, size parameter is not well defined.
3. Line 211, remove one ‘thresholds’
4. Line 298, this sentence is confusing. 

Comments on the Quality of English Language

The quality of English is good. I don't have comment on this.

Author Response

The paper is well written and I only have a few minor comments.

1. Line 102, font -> front?
2. Line 111, size parameter is not well defined.
3. Line 211, remove one ‘thresholds’
4. Line 298, this sentence is confusing. 

I thank the reviewer for carefully reading the manuscript.  The revised manuscript addresses the comments of the reviewer.  In particular, there is an extended discussion of the size parameter and the confusing sentence has been rephrased, hopefully to be an improvement.

Reviewer 4 Report

Comments and Suggestions for Authors

See the attached file for comments for the author.

Comments for author File: Comments.pdf

Author Response

The study examines the "decoherence" of cosmic ray extensive air shower particle 
detector signals through measurements of coincidence rates for pairs of detectors versus 
their separation. It looks at two scenarios: when only the two detectors trigger in 
coincidence, and when the coincidence trigger also requires detection of a local air shower 
by an external array. The study aims to understand the statistical properties of particle 
density measurements within air shower detection systems, particularly near the shower 
core. It hypothesizes that including the explicit air shower trigger will lead to different 
decoherence results compared to using only the two detectors. Without the Roof Array 
trigger, the decoherence curve followed a power law. With the Roof Array trigger, the 
decoherence curve became exponential, with a characteristic scale length that varied with 
shower size threshold and detector signal thresholds. The detector signal correlations also 
showed a transition from non-Poissonian to Poissonian behavior as the shower size and 
detector distance from the core increased. The inclusion of the air shower trigger added an 
extra constraint, selecting a subset of showers compared to the self-triggered case. This 
allowed investigation of particle density relationships within the air shower detection 
system, revealing characteristic scales related to the steep shower core region. 
Contribution to the field 
The study provides insights into the statistical properties of particle density measurements 
in air shower detectors, particularly near the shower core, which is relevant for 
understanding measurements in large air shower arrays. 
Structure and flow 
The paper is well-structured, with clear sections covering the background, methods, 
results, discussion, and conclusions. The flow of the analysis is logical and easy to follow. 
Achievements and significance 
The study demonstrates that including an explicit air shower trigger can provide additional 
information about the structure of air showers, beyond what can be learned from a simple 
two-detector decoherence experiment. 

Review conclusions 

The manuscript deserves to be published, but it needs some minor revisions. The clear and 
linear style of the exposition is remarkable, considering that similar experiments can be 
performed in laboratories with undergraduate students. In line with this approach, I 
suggest including a more detailed explanation of lines 94-96, describing how the area of 
the triggering detectors is related to the shower size in terms of number of particles and 
then to the primary energy. 
Other aspects to be addressed in the proposed revision include improving the formatting 
of the equations (e.g., line 113) and, most importantly, the quality of the plots. The figures 
currently included in the publication appear to be screenshots of plots created with 
spreadsheet software, which does not seem appropriate for the quality of a scientific 
journal article. 
Lines 199 through 204 contain comments on Figures 7 and 8, but there are no direct 
citations of the figures. Please add them. 
I suggest avoiding nested parentheses in lines 254-255. 
In Figures 11, 12, and 13, the 1:1 relationship and the values of +/- its square root are 
plotted as scatter plots. Even though they use distinct colors and markers with respect to 
experimental data, it can be a bit confusing. I recommend replacing these scatter plots 
with straight lines and adding a legend to the figures for direct explanation outside the 
caption. 
In line 350, remove one of the two trailing periods after the word "set".

I thank the reviewer for this detailed and constructive review.  I have attended to the typos identified by the reviewer and have improved Figures 11-13.  However, it is true that they were prepared in spreadsheets, but are not screenshots.  I believe that the figures, nonetheless, are clear and are appropriate for the journal.  The journal editor may comment if necessary.  Also, the Universe Word template was used and, again, I believe that the equation formatting is legible.

Explicit reference is now made in the text to Figures 7 and 8.

Comment is made to the relationship between shower size and the energy of the initiating cosmic ray particle.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The author has taken referee's comments into account, and extend discussion and conclusion sessions as suggested by referee. The paper can be published now.