Research on Wavelength-Shifting Fiber Scintillator for Detecting Low-Intensity X-Ray Backscattered Photons
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript is focused on enhancing the detectors for X - ray Compton backscattering imaging technology. The authors employed Geant4 to construct a model of the wavelength - shifting fiber (WSF) scintillator detector. They simulated the effects of various factors on the detection efficiency, developed the detector, and established an experimental system based on the simulation outcomes. The experiments validated that the optimization measures could boost the signal acquisition efficiency and image contrast. The content of the manuscript is logically well - organized, the experimental data are reliable, and the study shows good integrity. It is recommended that, after making some detailed revisions, the manuscript could be published in PHOTONICS.
- In the model, the distance between the two detectors in the X - axis direction is 50 cm. However, in the experiment, the distance between the two detectors on the X - axis is 5 cm. Why was the experimental verification not carried out according to the distance in the simulation? What conclusions would be obtained if the experiment was conducted following the simulated distance?
- It is advisable to present a comparison table contrasting with current relevant research methods to demonstrate the innovativeness of the research in this manuscript.
- There are certain flaws in Figure 2(b). It is suggested to substitute it with a clearer image.
- The image in Figure 7 has an excessive exposure level and insufficient clarity. It is recommended to replace it with a higher - resolution image.
- Both Figure 9 and Figure 10 require the provision of scale bars and color bars to convey adequate information.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsRecommendation: Accept after major revisions
Comments:
To advance high-sensitivity fiber scintillators, the authors studied the influence of X-ray source parameters and optical coupling mechanisms on the detection efficiency of wavelength-shifting fiber scintillator detectors. The study systematically evaluates the contribution of various factors to detection performance and offers valuable guidance for the design of imaging systems employing Compton scattering to achieve high signal-to-noise ratios. However, the paper lacks theoretical discussion, which is necessary for enhancing the reader’s understanding of both the underlying mechanisms and correlation between it to the experimental results. Such an approach would also strengthen the general applicability of the model, extending its relevance beyond the specific system studied. Overall, the paper should be reconsidered after major revisions (substantial revisions to text or experimental methods needed).
Specific comments:
1 For Figure 2a and 2b, please annotate the incident light, Compton-scattered particles, and the detector to enhance clarity. Additionally, we recommend revising Figure 2b to indicate the positions of the wavelength-shifting fibers (WSFs), scintillator, and detector more clearly.
2 In the "Results and Discussion" section, the authors simply present the experimental results; however, the discussion would benefit from a deeper integration of theoretical analysis, such as the theoretical relation between the Compton scattering efficiency and the geometric arrangement, the energy of incident particles and the energy transfer (fluorescence) between the scintillator and the WSFs, etc.
3 The authors demonstrated the high Compton scattering efficiency of the designed system. It would be useful to contextualize these results with other types of system using Compton scattering technology for high signal-to-noise ratio imaging.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors simulated a WSF scintillator detector model with Geant4 to study factors affecting detection efficiency. Epoxy resin coupling improved transmission efficiency significantly. The authors then constructed an X-ray detector and backscattering imaging system, obtaining high-contrast images to verify its performance.The author is requested to consider the following revision suggestions:
- The captions for Figures 2, 3, 8, and 10 need to be revised. Generally, the content displayed in the figures should be used as the subject, rather than "a" or "b".
- The multiplication sign in Figure 4 should not be represented by "*". It is more standard to use "×".
- Section 2 introduces the composition of the system model, parameters, and simulation steps. Please supplement the specific methods of simulation calculations so that readers can understand.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors addressed all the comments in the last review and the whole manuscript improved a lot from the last one. The revised manuscript offered clear interpretation of the experiment setting and the deeper integration of theoretical analysis will benefit the audiences in the community for their research. I would recommend to accept in present form.
Author Response
Thank you very much for your positive feedback and recommendation. I sincerely appreciate your time and effort in reviewing our manuscript and your helpful comments that contributed to its improvement. Your recognition is greatly encouraging, and we are grateful for your support.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper has been revised and can be considered for acceptance.
Author Response
Thank you very much for your positive feedback and recommendation. I sincerely appreciate your time and effort in reviewing our manuscript and your helpful comments that contributed to its improvement. Your recognition is greatly encouraging, and we are grateful for your support.
