A Novel, Rapid Response Renewable Biopolymer Neutron and Gamma Radiation Solid-State Detector for Dosimetry and Nuclear Reactor Flux-Power Mapping
Round 1
Reviewer 1 Report
See comments in the attached file.
Comments for author File: 
Comments.pdf
Author Response
Response to Referee 1
We sincerely appreciate the care taken to review and the kind words in recognizing the potential impact of the research reported in our manuscript. We generally accept all the comments/suggestions and have revised our manuscript accordingly. We believe our manuscript has improved in quality and are thankful to the referee.
The individual responses -accommodations to the 15 bulletized comments are provided below:
Response/Accommodation to Comment 1:
We indeed mean “bead,” not “beam.” Referee 1 requested an image of the PLA resin beads, and we have included the same as an inset in Figure 1.
Response/Accommodation to Comment 2:
We agree. The term “monoenergetic” was intended to indicate what is commonly deemed to be single energy photons emanating during Co-60 decay (in contrast with X-ray photons which exhibit a continuum in energy). To avoid needless distraction, the term “monoenergetic” is deleted.
Response/Accommodation to Comment 3:
Fig. 1 is enlarged for improved readability.
Response/Accommodation to Comment 4:
Figs. 2 are enlarged for improved readability.
Response/Accommodation to Comment 5:
Figs. 4 and 5 are enlarged for improved readability. The color palette numbering is derived MCNP code simulation related graphics.
Response/Accommodation to Comment 6:
We agree. The stars have been repositioned.
Response/Accommodation to Comment 7:
We agree. “P” was previously used to represent photons (i.e., gamma radiation). The Table 1 labels have been changed to remove “P” and replace it with the Greek symbol for gamma.
Response/Accommodation to Comment 8:
Re: Fig. 7 (which should have been Fig. 6 for continuity), the results of repeat experiment checks were obtained independently (and after a significant multi-month gap in time using a similar but re-assembled setup) by a co-author are indeed seen to be somewhat lower and attributed to a somewhat lower ~49.5oC vs ~50oC acetone temperature bath type effect). However, the repeat results (e.g., the red open circles for 40 kGy irradiation dose) does indeed overlap with the spread of data from the prior (pristine) results. The text is re-written to clarify on this point.
Response/Accommodation to Comment 9:
We appreciate the requests for clarification. First of all, the (0,0) point refers to 0-kGy (i.e., un-irradiated) PLAD sample testing which was indeed conducted. This is clarified in the text. At For these scoping tests at 50oC (acetone bath temperature) the PLA resin was unaffected – the RMD was noted to be nil. Consequently, we believe it is appropriate to depict a trend line starting from (0,0). We have clarified that the error bars represent the spread of the data about the mean value.
Response/Accommodation to Comment 10:
The equipment utilized a temperature regulator source of thermal energy due to which we believe the measured acetone bath temperature reading remained constant over the 20 min. time frame for each test.
Response/Accommodation to Comments 11-14:
We agree with the referee. In the start of the section “Results and discussion” we now clarify and correct in response to this comment. The figure labels showing results indicate that the error bars (where indicated) represent the actual spread of the data about the mean value. it is inappropriate to cite the calculated 1 SD value assuming a normal distribution, in experiments with only 3-4 test data points. Instead, the label for each subsequent figure includes a note to clarify that the results of RMD from the experiments are “all” included in subsequent plots. For specific cases where multiple samples were tested for a given temperature and dose, the mean value is accompanied with an error bar showing the spread of the RMD around the mean value. Where only a single sample was tested, the RMD is depicted without an error bar. The verbiage “compatible” is included. Table 2 is replaced with a new table which summarizes the experimental test matrix.
Response/Accommodation to Comment 15:
We appreciate the comment and request to discuss the time needed for an actual field implementation. We believe more in-depth assessments need to be made but using the present protocol with 20 min. of dissolution, the overall mapping of power and flux should be possible to conduct within 0.5h; further optimization makes it feasible (but not yet verified) to bring the time down to under 5 min. We have included additional verbiage in the text per the referee's recommendation.
In conclusion, we agree with the comments and suggestions made by the referee. The comments were valuable in improving our manuscript and we are deeply appreciative.
Reviewer 2 Report
Comments for author File: Comments.pdf
Author Response
Response to Referee 2
We appreciate the comments and suggestions for consideration by Referee 2. Our responses and accommodations are provided below:
Paper Text-Related Response to Comments and Suggestions:
The Abstract length has been reduced to ~300 words.
As recommended, we have summarized the implications of the importance of distinguishing neutron vs gamma radiation flux and dosimetry in the final sentences of the Abstract.
The relevance, significance and importance of PLAD have been discussed in the Introduction section and in the Abstract.
The introduction section (upfront) now discusses the relevance and need for the novel PLAD-based approach. A new reference is included. To aid the general audience, we have included a discussion on alternate instrumentation used for neutron-gamma dosimetry.
We have separated the Experimentation and Methodology discussions in the manuscript as mentioned by the referee.
Title Related Response-Accommodation:
We have considered the referee’s discussion for composing our manuscript’s title.
Reviewer 3 Report
This paper evaluates a biopolymer dosimeter for neutrons and gamma rays.
Abstract: define acronyms RMD and LWR
Figure 1: label isodose values? Dimensions in cm?
Line 203: wording is poor – reword.
Line 212: clarify how the ratio is determined. Show a formula? (initial mass – final dried mass)/initial mass? This is shown later.
Dissolution probably depends on time – how was the time to use determined? Dissolution probably occurs only at the surface not the bulk – true?
What chemically is actually dissolved? Polymer fragments? Atoms?
Why was acetone chosen rather than some other solvent?
Is there a physics reason why the neutron and gamma ray dose impacts differ at ~40C acetone? What is the physics behind the onset of RMD at a certain temperature?
Was a RMD test performed on samples that were only heated to high temperature but not exposed to radiation?
Author Response
Response to Referee 3
We sincerely appreciate the care taken to review and the kind words in recognizing the potential impact of the research reported in our manuscript. We generally accept all the comments/suggestions and have revised our manuscript accordingly. We believe our manuscript has improved in quality and are thankful to the referee.
The individual responses -accommodations to the 9 bulletized comments-requests are provided below:
The acronyms LWR and RMD are defined.
Figure 1 caption now includes clarification that the isodose curves represent relative axial and radial variations.
Line 203 (Original) has been reworded for clarity.
Line 212 (Original) has been revised to include the formula for RMD at this location.
We agree that dissolution time is an important parameter; for our experiments, the 20-min. period was chosen from experience for these studies but is not currently deemed optimal. More research is warranted, and we include this remark in the revised document.
We believe it is the PLA surface that starts dissolving inwards. However, the acetone-bath contents have to be studied for detailed understanding.
We chose acetone since it is a standard, low-cost, easy to handle, and utilizes laboratory solvent valuable for numerous reasons; we have been using it for several decades in our laboratory and have included a discussion in para.4 of the Introduction section.
The underlying physics of acetone-based dissolution of neutron vs. gamma irradiated PLA is not yet understood; this requires further studies.
Yes, RMD was indeed performed for non-irradiated PLA samples subject to 300C. This is included in Fig. 12 as a data point for 0 kGy dose.
Round 2
Reviewer 1 Report
I appreciate the efforts made by the authors to improve the overall quality of the manuscript. The document now represents a more rigorous analysis with an appropriate presentation of results, graphs, and pictures.
In addition, the authors have clarify my concerns by including new text in the document.
I recommend the manuscript for publication.
Reviewer 2 Report
The author has made substantial revisions to the manuscript based on the suggestions. The current version of the revised manuscript is suitable for publication.
Reviewer 3 Report
The revised paper is acceptable.
