Perovskite Nanocrystal-Coated Inorganic Scintillator-Based Fiber-Optic Gamma-ray Sensor with Higher Light Yields

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this manuscript, the authors reported inorganic scintillators coated with perovskite nanomaterials to detect gamma rays with high-light yields. This work is well done, so I suggested this manuscript be accepted for publication, provided following questions have been addressed.

1. TEM images of perovskite nanocrystals in toluene and PMMA should be provided, in order to estimate the size distribution of perovskite nanocrystals.

2. The authors should explain why the thickness of scintillator and PMMA concentration can affect the photon counting results? Why do all curves in Figures 10 and 11 tend to increase and then decrease? Will the size of perovskite nanocrystals influence the photon counting results?

3. The authors mentioned some data are presented in Table 3, but I have not found it.

4. Comparisons with scintillators in other literature are lacking in this work

5. Please check the units of the Y-axis coordinate in Figures 10, 11, 12-15.

Author Response

Thank you for your comment. Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

 

Thank you for submitting your paper titled “Perovskite Nanocrystal-coated Inorganic Scintillator-based Fiber-optic Gamma-ray Sensor with Higher Light Yields” for publication in Photonics. This is a fascinating piece of research that makes advances in the use of perovskite-coated inorganic scintillators for gamma-ray sensors. While the study is indeed compelling, I believe it requires major revision. Below, I have provided my general and specific comments on the paper.

 

Kind regards, 

Reviewer

 

General comments.

To enhance the readability of the paper, including an abbreviation list in a single location where all abbreviations are referenced would be beneficial. Even though the abbreviations are defined within the paper, having a dedicated section for them would be convenient.

 

In the Introduction section, it is mentioned that Ba-133 has less distinct peak regions. The study demonstrates an improvement in resolutions. Could you measure the improved resolution with Ba-133 as well, to show that the peak regions are better resolved?

 

Specific comments.

Line 57.

The highest energy of beta particles released in tritium decay, called the endpoint energy, is just under 20 keV. Because of their low energy, beta particles from tritium don't travel very far. Will the scintillation response from tritium's beta decay be comparable to the response to gamma particles used in this study?

Line 58.
The phrase "relatively short half-life of 12 years" for tritium should be clarified when discussing its use in emergency exit signs. In the context of nuclear remediation within the CANDU nuclear industry, this 12-year half-life is considered quite long.

Figure 1.

It would be useful for reader if additional details related to the figure will be provided in the caption of the figure or in the text (what horizontal and vertical dashed lines means?). What is typical scale for the time if half-life of tritium of 12 years considered is relatively short. Does the time scale of 12 years is also applied here?

Lines 167 to 177 and Figure 7.

The decay of Co-60 primarily involves a beta minus transition with an endpoint energy of 317.32 keV and a high probability of 99.88%. When Co-60 decays to Ni-60 (stable), it emits two gamma rays with energies of 1173.240 keV and 1332.508 keV, which happen with probabilities of 99.85% and 99.9988%, respectively. There are also two less common beta minus transitions with endpoint energies of 664.46 keV (0.002% probability) and 1490.56 keV (0.12% probability). The arrangement of the Co-60 source in near surfaces geometry is significant. If the Co-60 source is configured in a certain way, it emits beta particles with enough energy to reach perovskite-coated inorganic scintillators and produce light. Further information on the Co-60 source and its placement relative to the perovskite-coated inorganic scintillators is necessary. To isolate gamma particles produced from the decay of Co-60, an absorber with a specific thickness is positioned to block most of the beta particles.

Line 238.

The fact that there are 5 digits after the decimal indirectly indicates the uncertainty in determining the maximum range of beta particles. Please demonstrate or calculate the uncertainty for the maximum range of beta particles estimated using Equation (1).

Figure 13.

Please explain how the peak resolutions of 8.47% and 7.93% were determined. From the figure, it is not clear whether you used a Gaussian fit function to obtain the width for the Cs-137 peak or if a different approach was used. Please provide additional details either in the caption of the figure or in the text. Additionally, it's unclear what assumptions were made for the 'Calculated value' of 8.01%.

Equation (2).

The right-hand side of Equation (2) suggests that three factors influence the amplitude of the PMT output pulse. Yet, in the explanation of each factor, only two are defined.

Lines 266, 267.

Energy resolution is a measure of a detector's ability to distinguish between different energies of radiation. A lower percentage value indicates better resolution, as it means the detector can more precisely differentiate between closely spaced energy levels. In your statement, "the energy resolution of the peaks increased from 8.47% to 7.93%," a decrease from 8.47% to 7.93% represents an improvement in energy resolution, not an increase. Therefore, the correct wording should be: "Consequently, the energy resolution of the peaks improved from 8.47% to 7.93%."

Lines 276, 277.

Saying that ‘v(M) is the variance’ and that ‘v(M) is the PMT gain’ is contradictory.

Lines 282, 283.

What is the uncertainty in the estimated value of 8.01% and the measured value of 7.93%?

Figure 14.

Please review the feedback regarding Figure 13 and make the necessary changes.

Lines 290.

What is the uncertainty for values of 11.7% and 16.4%?

Figure 15 (b).

What are the error bars for each point at Figure 15 (b)?

 

Author Response

Thank you for your comment. Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for addressing my concerns and comments. Thank you for providing detailed explanations on the uncertainty estimations. I really like that the abbreviations are also located in a single place, making it easy for the reader to refer to them. Moreover, I appreciate that you have highlighted the changes in the text.

I have found two minor typos that would be useful to fix before publishing.

Line 109:

I believe "Figure 1" should be changed to "Figure 2."

Line 112:

I believe "C_s" should be changed to "Cs."

Again, thank you for your detailed explanations and for addressing all my comments.

Kind regards,

Reviewer