## 6 Summary and Discussion  
In this study, an array-type scintillator detector was designed for fast neutron imaging. Through Monte Carlo simulations, the main parameters of the detector were optimized. In addition, the prototype of this detector was fabricated and tested, which was composed of scintillator array basic units with a dimension of 1 mm \(\times\) 1 mm \(\times\) 25 mm, 16 \(\times\) 16 SiPM array, and self-design capacitive multiplexing network electronics. Using the D-T fast neutron source, stainless-steel sample imaging was obtained with a minimum spatial resolution of 1.2 mm.  
The radiation damage of these SiPMs was also considered in the test [30]. After the radiation of the 14 MeV D-T neutron beam for 24 h, the gain in these SiPMs was measured and compared with that without radiation. The results demonstrated that the gain decreased and the dark current increased apparently. However, it could still work normally in the avalanche mode, which indicated that it had certain radiation resistance. Nevertheless, the initial research data were not comprehensive enough. Subsequent separate tests will be conducted, and corresponding articles will be published to discuss and explain relevant irradiation damage problems.  
To avoid the long-time irradiation damage of these SiPMs, a new detector with a long bending scintillating fiber array can be designed. In addition, the SiPM array can be placed in the position without direct exposure to the neutron.  
SiPMs have an increasingly wide range of applications owing to their high photon gain, low operating voltage, and relatively low cost. SiPMs can be assembled into photon detection modules with arbitrary sizes. After the spatial resolution is improved to a sufficient level, these modules can be used for non-destructive detection of larger volume objects.  
Conceptualization, B.T., R.C. and Z.S.; methodology, B.T., X.C. ([PERSON]) and R.C.; software, C.H., X.C. ([PERSON]) and X.W.; validation, B.T., S.C. and Z.Z.; formal analysis, Z.Z. and Z.S.; investigation, X.C. ([PERSON]) and Q.Y.; resources, R.C., P.Z., Z.S., Y.W. and Y.L.; data curation, X.C. ([PERSON]), Q.Y., C.H., X.C. ([PERSON]) and D.G.; writing--original draft, X.C. ([PERSON]); writing--review and editing, X.C. ([PERSON])and B.T.; visualization, C.H. and S.C.; supervision, H.X. and L.Y.; project administration, B.T and R.C.; funding acquisition, B.T. All authors have read and agreed to the published version of the manuscript.  
Figure 12: (**a**) A raw 2-D image without the correction of the stainless-steel sample with the sample shape overlay on it; (**b**) projection of a part section (red box) on the \(x\)-axis.  
**Funding:** This study was funded by Guangdong Basic and Applied Basic Research Foundation, China, grant number 2022B1515120071.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The raw data in this paper are based on the experiments conducted within the authors' team. The data presented in this study are available on request from the corresponding author ([EMAIL_ADDRESS]). The raw data supporting the conclusions of this article will be made available by the authors on request.  
**Acknowledgments:** Thanks for the assistance provided by [PERSON] and his team throughout the entire experimental process. Thanks to the China Academy of Engineering Physics for providing the neutron source.  
**Conflicts of Interest:** The authors declare no conflict of interest.