Luận án Experimental validation of nuclear data in the k₀-standardized neutron activation analysis using the dalat research reactor

lot of neutrons, samples can be neutron activated quickly and effectively [7]. 3.2.2 The k0-NAA in Dalat nuclear research reactor The k0-NAA method has been implemented in the NAA laboratory at DNRR, and advancements in computer technology, evaluation programs, and laboratory instrument have led to re-validation of this standardization technique in laboratory. 3.3 Practical Experiment in Dalat nuclear research reactor 3.2.1 Sample preparation Table 3.2 Sample preparation. No. Name Type of sample Sample ID Mass (g) 1 IRMM 530R Al-0.1%Au Comparator A0289 0.00411 2 SMELS I Reference Material SM21a 0.03185 3.2.2 Prepare monitors Table 3.2. Description of sample preparation conditions under the k0-IAEA program. No Standard sample Code Matrix sample Geometry Weight of sample (mg) 1 Al-0.1%Au Au1102 Al-metal Foil 5.510 2 None BLK-1 None None 4000 3 NIST-2711a MO195 Plant leaves Powder/liquid 100.880 Page 19 of 29 4 NIS-1570a SP4 Al-metal Foil 204.200 5 NIST-1566b OT21 Plant leaves Powder/liquid 198.800 6 Al-0.1%Au Au1100 Al-metal Foil/wire 7.200 3.2.3 Measurement of monitors The samples were measured on a digital signal processing gamma spectrometer system comprising a 30% efficient HPGe detector (GMX 30190) and a transistor erasing preamplifier with high count rates, fast changes, and multiple functions. 3.2.4 The use of specialized program k0-IAEA To use the k0-NAA method, you need to do two main things: find out the neutron spectral paramters at the sample irradiation position and check how well the gamma spectrometer system records. Table 3.3. Neutron spectral parameters of sample in channel 7-1 in the thermal column. Parameter Value Uncertainty th 3.80E+16 n.cm -2s-1 1.524E+14 n.cm-2s-1 f 9.86 0.10  -0.0676 0.0006 3.2.5 Sample Irradiation of the seven short-lived radionuclides Table 3.5. The irradiation, decay and counting times for determination of k0 factor. Radionuclides Ti(s) Td (s) Tc (s) Distance to Detector (mm) 66Cu, 52V 70 s (~30 mg) 5-10 m 300 51 198Au, 38Cl, 134mCs, 128I, 140La, 56Mn 1-2 h 900 51 Table 3.6. SRMs and comparator information. Sample name Element Assigned Value ± U mg/kg-1 SMELS Type I Au 82.7 ± 1.7 Cl 4330 ± 170 Cs 897 ± 37 Cu 3930 ± 120 I 152 ± 5 La 265 ± 10 Mn 113.9 ± 3.3 V 39 ± 1.6 IRMM 530R Al-0.1%Au Au 1003 ± 12 3.2.6 Calibration of neutron spectra in Channel 7-1 Table 3.7. Irradiation channel neutron spectral parameter. Parameter Value Uncertainty th (n/m2/s) 3.80E+16 1.524E+15 f 9.86 0.10 Page 20 of 29  -0.0676 0.0006 Table 3.8. Nuclear parameters condition for k0-NAA. Element X (n, x) Y T1/2 Eγ (keV) Au 197Au (n, γ) 198Au 2.695 d 411.8 Cl 37Cl (n, γ) 38Cl 37.24 min 1642.7, 2167.4 Cs 133Cs (n, γ) 134mCs 2.903 h 127.5 Cu 65Cu (n, γ) 66Cu 5.12 min 1039.2 I 127I (n, γ) 128I 24.99 min 442.9 La 139La (n, γ) 140La 1.678 d 328.8, 487.0, 596.2 Mn 55Mn (n, γ) 56Mn 2.579 h 846.8, 1810.7 V 51V (n, γ) 52V 3.75 min 1434.1 3.2.7 Irradiation measurement The HPGe detector was used to measure gamma-rays emitted from the irradiated samples. The efficiency of absolute full energy peak detection was calibrated using a standard gamma-ray source of 152Eu, and the efficiency curve at 51 mm to the detector. Chapter 4: Results and discussion 4.1 Results The present study focused on determining seven radionuclides using the k0 factors. The α and ƒ values obtained from Table 3.4 were used to calculate the k0 factors by the equation (2.60) and k0 factors were determined using the "bare monitor" method. It was observed that the α and ƒ values obtained in this study agreed with the literature values of DNRR [24]. The k0 factors were determined using the "bare monitor" method. Table 4.1 presents the experimental results of the k0 factor determination for short- and medium-lived radionuclides using DNRR, and the obtained values were compared with the k0 references [16]. Regarding the contribution of the parameters such as sample mass, irradiation time, decay time, and counting time, are less than 0.1%, Q0 and f are about 1.0%, α is less than 1.5% and overall, they are about 3.24%, that all of which are in the agreement with the k0 reference as shown in Table 4.3. Table 4.1. Experimental k0, Au -factors of the short- and medium-lived radionuclides compared to the k0 reference using Channel 7-1 facility at DNRR. Nuclides E𝛾 (keV) k0-experiment Uncertainty k0-Reference [16] Exp / Ref 198Au 411.8 - - 1 - 52V 1434.1 1.969E-01 1.237E-02 1.96E-01 1.004 66Cu 1039.2 1.868E-03 1.156E-04 1.86E-03 1.004 38Cl 1642.7 1.893E-03 1.197E-04 1.97E-03 0.961 38Cl 2167.4 2.595E-03 1.635E-04 2.66E-03 0.976 134mCs 127.5 4.768E-03 3.049E-04 5.74E-03 0.831 128I 442.9 1.185E-02 7.582E-04 1.12E-02 1.065 140La 328.8 2.687E-02 1.679E-03 2.87E-02 0.936 140La 487 6.080E-02 3.789E-03 6.37E-02 0.955 140La 1596.2 1.279E-01 8.013E-03 1.34E-01 0.955 56Mn 846.8 4.887E-01 3.028E-02 4.96E-01 0.985 56Mn 1810.7 1.314E-01 8.120E-03 1.35E-01 0.973 Table 4.2. Relative standard uncertainties of parameters in the k0-NAA standardization. Page 21 of 29 Parameter Contribution Mass ~0.1% Q0 ~1.0% α ~1.5% f ~1.0% Efficiency ~2.0% Concentration ~1.5% Irradiation time, Decay time, Counting time Less than ~0.1% Overall ~3.24% 4.2 Discussions 4.2.1 Research results This section provides a detailed discussion of the experimental k0 factors obtained in this study. It is divided into three main parts: characterization of the neutron irradiation, calibration of gamma-ray spectrometers, and validation of the results using SRMs. Tables and figures are included in this section to support the discussion, and a summary is provided at the end. This study used seven short- and medium-lived radionuclides for neutron activation analysis. These samples were prepared in polyethylene boxes and irradiated at channel 7-1 of the DNRR for 70 seconds. The FWHM was 1.9 keV at 1132 keV, and the efficiency was calibrated using 152Eu at 51 mm. The HPGe detector (GMX-30190) was used to count the samples with a relative efficiency of 30%. Decay times ranged from 5-10 minutes for short-lived radionuclides and 1-2 hours for medium-lived radionuclides, and the counting time was set at 300 seconds and 900 seconds. All parameters are shown in Tables 3.8, Table 3.9, and Table 3.10. The accuracy of the reference materials was analyzed with the sample, and the nuclear reactions necessary for obtaining the results were characterized, particularly the short-lived irradiation of the SMELS materials. Gamma-ray spectrometers were calibrated using an HPGe detector (GMX-30190) to calibrate for energy, peak width, and full energy detection efficiency, as shown in Fig. 21. The calibration results showed that the value of 𝜙th is 3.80×106 n/m-2.s-1, ƒ is 9.86, and α is -0.0676. The calibration of the detector's energy efficiency detection and full peak energy was in good agreement with the standard value of the reference. The accuracy of the detector response functions for low activity was also calibrated. This allowed for simultaneously determining several other short-lived or detectable radionuclides contained elsewhere. However, it is important to consider the setting and self- grinding of the matrix in the container, and the matrix was kept compact. The volume in the container is fixed to ensure stability and non-alteration of the matrix in long- term usage. The ready standard has also fixed the volume that cannot be changed during transportation and usage of the standard, and natural matrices were used in the properties as close to the analyzed sample as possible. Page 22 of 29 Table 4.3. Values of k0,Au determined by this work and the other authors. Radionuclides (Energy, keV) This work ± Unc. Reference [16] ± Unc. Reference [26] ± Unc. IAEA [41] ± Unc. Reference [42] ± Unc. 52V (1434.1) 1.97E-1 ± 1.24E-2 1.96E-1 ± 2.35E-3 2.00E-1 ± 2.40E-3 1.96E-1 ± 2.35E-3 2.00E-1 ± 2.20E-3 66Cu (1039.2) 1.87E-3 ± 1.16E-4 1.86E-3 ± 9.30E-6 1.76E-3 ± 8.80E-6 1.86E-3 ± 9.30E-6 2.03E-3 ± 2.03E-5 38Cl (1642.7) 1.89E-3 ± 1.2E-4 1.97E-3 ± 2.76E-5 2.30E-3 ± 3.22E-5 1.97E-3 ± 2.76E-5 2.06E-3 ± 2.88E-5 38Cl (2167.4) 2.60E-3 ± 1.64E-4 2.66E-3 ± 3.46E-5 2.72E-3 ± 3.81E-5 2.66E-3 ± 3.46E-5 2.75E-3 ± 3.58E-5 134mCs (127.5) 4.77E-3 ± 3.05E-4 5.74E-3 ± 9.76E-5 5.35E-3 ± 9.10E-5 5.74E-3 ± 6.89E-5 - 128I (442.9) 1.19E-2 ± 7.59E-4 1.12E-2 ± 1.90E-4 1.79E-2 ± 3.04E-4 1.16E-2 ± 1.62E-4 - 140La (328.8) 2.69E-2 ± 1.68E-3 2.87E-2 ± 2.87E-4 2.48E-2 ± 2.48E-4 2.87E-2 ± 2.87E-4 2.83E-2 ± 3.11E-4 140La (487) 6.08E-2 ± 3.79E-3 6.37E-2 ± 5.73E-4 5.77E-2 ± 5.19E-4 6.37E-2 ± 5.73E-4 6.26E-2 ± 6.26E-5 140La (1596.2) 1.28E-1 ± 8.02E-3 1.34E-1 ± 1.47E-3 1.28E-1 ± 1.41E-3 1.34E-1 ± 1.47E-3 1.30E-1 ± 5.20E-4 56Mn (846.8) 4.89E-1 ± 3.03E-2 4.96E-1 ± 2.98E-3 5.01E-1 ± 3.01E-3 4.96E-1 ± 2.98E-3 5.02E-1 ± 5.02E-3 56Mn (1810.7) 1.31E-1 ± 8.13E-3 1.35E-1 ± 5.40E-4 1.38E-1 ± 5.52E-4 1.35E-1 ± 5.40E-4 1.37E-1 ± 1.23E-3 * Remark: Unc. = Absolute uncertainty. Page 23 of 29 Table 4.4. The comparison of analysis results (mg/kg) based on the experimented and referenced k0,Au factors. Elements Radio- nuclides Ce Ue Cr Ur Cc Uc cC/ eC cC/ rC Using k0,Au factors (experiment) Using k0,Au factors (reference) Certified values Experiment/ Certified Reference/ Certified V 52V 38 2 42 2 39 2 0.97 1.08 Cu 66Cu 4284 171 4039 7 3930 118 1.09 1.03 Cl 38Cl 4407 176 4313 173 4330 173 1.02 1.00 Cs 134mCs 934 56 776 47 897 36 1.04 0.87 I 128I 151 8 143 7 152 5 0.99 0.94 La 140La 267 19 254 18 265 11 1.01 0.96 Mn 56Mn 111 3 108 3 114 3 0.97 0.95 Remarks: Ce and Ue - The experimental concentrations and uncertainties, respectively obtained using the k0,Au values in this work; Cr and Ue - The reference concentrations and uncertainties, respectively obtained using the k0,Au values from references of DeCort, 2003 [17]; Cc and Uc - The certified concentrations and uncertainties of the certified reference material (SMELS Type-I). The comparison of the determined k0,Au factors (Ce) experimentally with those from references (Cr) showed a good agreement with certified values (Cc) for various elements (see Table 4.4). The ratios Ce/Cc and Cr/Cc, which measure agreement, are consistently close to one, confirming that both the experimentally determined and reference k0,Au factors are reliable for analysis of the elemental concentrations of interest. We carefully considered uncertainty, represented by Ue and Ur for the experimental and reference k0,Au factors resulted in a high accuracy of the k0-based method as demonstrated in this study. However, upon closer investigation, there are slight differences, especially for Cu (this work) and Cs (reference). In these cases, experimentally determined and reference values deviated from certified values of 9% and 13%, respectively. This observation suggests a further research to the specific conditions or factors affecting the determination of k0,Au factors for these elements. This detailed investigation would be crucial for improving the method and ensuring higher accuracy for analyses in the future. In summary, the concentrations and uncertainties of the experimental and reference of k0,Au factors. The value of k0,Au factors obtained in this work for some short and medium-lived radionuclides (52V, 66Cu, 38Cl, 134mCs, 128I, 140La, and 56Mn) have been assessed by analyzing the SMELS Type-I. The deviation of the results of analysis for SMELS Type-I with the experiment and reference k0,Au factors as compared with the certified values were within ± 9.0% and ± 13.0%, respectively. The comparative results showed that the experiment k0,Au factors done by this study were acceptable and better agreement as compared with the reference ones. Page 24 of 29 4.3 Conclusions and future work 4.3.1 Conclusions The Dalat Nuclear Research Reactor (DNRR) was used to test and confirm the k0 factors needed for the k0-standardized neutron activation analysis (k0-NAA) Experimental validation of the k0 factors required by the k0-standardized neutron activation analysis (k0-NAA) using the Dalat Nuclear Research Reactor (DNRR) was done. The new k0 factors of 7 short and medium-lived radionuclides, were evaluated, including: 66Cu, 52V, 38Cl, 134mCs, 128I, 140La, and 56Mn, which were determined at DNRR. Perform the k0-NAA using the new k0 dataset to determine the concentrations of the elements in the reference materials (RMs) against the certified concentration values. The difference between the experimental results of determining the new k0 factors and the reference values (literature) is less than 7%. From there, applying the new k0 factors to k0-NAA at DNRR resulted in the elemental concentrations in the RMs compared to the certified values in the range of 7-11%. Exception for 134mCs, which were biased by 19%. This work conducted the experiments at DNRR, including the characterization of the Channel 7-1; calibration of the gamma-ray spectrometer using the HPGe detector; and the data processing that is required by the k0-NAA method with experimental parameters (neutron field parameters, detector efficiency, corrections, etc.). The "self-characterization" method for Channel 7-1 using synthetic multi-element standard samples (SMELS I) was the first use regarded as simple and convenient experimentally, with results consistent with the conventional method using independent monitors. To sum up the result of the experimental validation of nuclear data in k0-NAA as using the Dalat nuclear research reactor (DNRR), it can be seen that Table 12 presents the experimentally determined k0 factor of 11 gamma-rays from 7 radionuclides of both short- and medium-lived nuclides using the DNRR. The results are compared with the recommended literature value and k0 reference. It was found that the k0 factors for the short-lived radionuclides 52V at 1434.1 keV and 66Cu at 1039.2 keV, as well as the medium-lived radionuclide 128I, are similar to the k0 factors for short-lived radionuclides 52V at the energy of 1434.1 keV and 66Cu at the energy of 1039.2 keV, as well as medium-lived radionuclides 128I, are determined and are in good agreement with the result of the k0 reference. It is important to note that 52V, 66Cu, and 128I emit only a single gamma ray, and there is no true coincidence effect. The ratio of the experiment to reference is 1.004 for both isotopes. 38Cl and 56Mn, which emit two gamma-rays with a high emission probability, the experimental results for determining the k0 factor are also in good agreement with the k0 reference. The differences between the experiment and reference values are less than 3%. For other radionuclides, such as 140La, which had three different gamma-ray energies, the k0 factor was generally in good agreement compared to the reference information. However, for 134mCs, a medium-lived radionuclide with an energy of 127.5 keV, the experiment value was compared to the k0 reference, and the Exp./Ref ratio. was 8.31E-01. The k0 factor of 134mCs has a high difference with the k0 reference value because this energy is in a low energy region (< 200 keV), and some effects from Compton or low X-ray may influence the results. Thus, 134mCs appear to be not good due to low uncertainty. The determination of the k0 factor measured the absolute uncertainty and was calculated based on the component of parameter error propagation. The uncertainties obtained uncertainties for determining the k0 factor for short- and medium-lived radionuclides were reported in the study. Page 25 of 29 4.3.2 New points of discussion To validate the k0 experiment used in my own experiments, I compare them with those reported by different authors in the field [16, 26, 41, 42]. This will involve a thorough review of the literature, looking for studies that have used similar reactor and neutron spectra to those used in my experiments. This comparison will be critical for validating the nuclear data used in my experiments, as well as for ensuring that my experimental results are in good agreement with the reference values. Any discrepancies or differences between my k0 values and those reported in the literature will need to be carefully investigated, to ensure that my results are as accurate as possible. In addition to comparing my k0 experiment with those reported in the literature, I will also need to consider any potential sources of error in my own experiments. This may involve a careful analysis of the data, looking for any systematic errors or biases that could affect the accuracy of my results. I will also need to consider the effects of any uncertainties in the nuclear data used in my experiments, and to quantify these uncertainties wherever possible. 4.3.2 Future plan A Future plan in this research area is proposed to investigate and re-determine the k0 factors of very short-lived radionuclides (less than 20 seconds), such as 77mSe and 20F as follows: (1) There is a lack of experimental data for these radionuclides, and additional experiments are needed to improve their accuracy and reduce the uncertainty of their k0 values. (2) Re-determination of k0 factors for radionuclides with high uncertainties, such as 133Ba is needed. This will help to improve the accuracy of k0 factor and increase the reliability of the k0-NAA method for the element. (3) Determination of the k0 factor for 152Eu at low energy (46 keV) is proposed because it is missing in the current k0 dataset. Papers published using for the dissertation 1. Ho Manh Dung, Tran Tuan Anh, Tran Quang Thien, Ho Van Doanh, Truong Truong Son, Phonesavanh Lathdavong, Analysis of automobile window glass samples by the k0-based Neutron Activation Analysis for forensic applications, Journal of Radioanalytical and Nuclear Chemistry, Volume 332 (2023) 3493- 3498; 2. Ho Manh Dung, Phonesavanh Lathdavong, A review of nuclear data for the k0- based neutron activation analysis, Journal of Nuclear Science and Technology, Vietnam, Vol.9, No. 1 (2019) 28-33; 3. Phonesavanh Lathdavong, Ho Manh Dung, Tran Quang Thien, Doanh Van Ho, Son Truong Truong, Self-characterization of irradiation facility using synthetic multi-element standard (SMELS) for the determination of k0-factors of seven radionuclides of interest, Journal of Nuclear Science and Technology, Vietnam, accepted for publishing in September 2023; 4. Ho Manh Dung, Tran Tuan Anh, Ho Van Doanh, Tran Quang Thien, Nguyen Thi Tho, Trinh Van Cuong, Truong Truong Son, Phonesavanh Lathdavong, Evaluation of “k0-DALAT” software for the k0-Standardized neutron activation analysis, VINANST-14, Da Lat, 09-10/12/2021. Page 26 of 29 References [1] Gibbons, D., & Kruger, P. (1971). Principles of activation analysis. John Wiley & Sons. Wiley-Interscience. [2] Hamidatou, L. A. (2019). Advances technologies and applications of neutron activation analysis. IntechOpen. https://www.intechopen.com/books/6336. DOI: 10.5772/intechopen.69725. [3] IAEA (2001). Use of research reactors for neutron activation analysis (IAEA- TECDOC-1215). IAEA-Vienna. [4] Speakman, R. J., & Glascock, M. D. (2007). Acknowledging fifty years of neutron activation analysis in archaeology. Archaeometry, 49, 179-183. [5] Byrne, A. R., & Kucera, J. (1997). Role of the self-validation principle of NAA in the quality assurance of bioenvironmental studies and in the certification of reference materials. Proc. Int. Symp. Harmonisation of Health-related Environ. Measurements using Nucl. and Isotopic techniques (Hyderabad, 4–7 Nov. 1996), IAEA Vienna (1997) 223–238. [6] k0-International Scientific Committee (k0-ISC). Classic k0 Database. 2012. [7] Dung, H. M., & Hien, P. D. (2003). The application and development of k0- standardization method of neutron activation analysis at Dalat research reactor. Journal of Radioanalytical and Nuclear Chemistry, 257(3), 643-647. [8] Greenberg, R. R., Bode, P., & Fernandes, E. A. D. N. (2011). Neutron activation analysis: A primary method of measurement. Spectrochimica Acta, B66, 193-241. [9] Kučera J., Byrne A.R.: Role of the self-validation principle of NAA in the quality assurance of bioenvironmental studies and in the certification of reference materials. IAEA-SM-344/8, IAEA Vienna, 1997. [10] De Corte, F. (1999). Thirty years of NAA developments and applications at the Thetis reactor of the Institute for Nuclear Sciences, Gent. Czechoslovak journal of physics, 49, 247-254. [11] Freitas, M. C., Reis, M. A., Marques, A. P., Almeida, S. M., Farinha, M. M., De Oliveira, O. M., Ventura, M. G., Pacheco, A. M., & Barros, L. P. (2003). Monitoring of environmental contaminants: 10 years of application of k0- INAA. Journal of Radioanalytical and Nuclear Chemistry, 257(3), 621-625. [12] Byrne, A. R. (1993). Review of neutron activation analysis in the standardization and study of reference materials, including its application to radionuclide reference materials. Fresenius' journal of analytical chemistry, 345, 144-151. [13] Řanda, Z., Kučera, J., & Soukal, L. (2003). Elemental characterization of the new Czech meteorite ‘Moravka’ by neutron and photon activation analysis. Journal of Radioanalytical and Nuclear Chemistry, 257, 275-283. [14] Santos J. O., Munita C. S., Toyota R. G., Vergne C., Silva R. S., Oliveira P. M. S.: The archaeometry study of the chemical and mineral composition of pottery from Brazil’s Northeast. J. Radioanal. Nucl. Chem. 281 (2009), p. 189–192. [15] Pomme, S., Hardeman, F., Robouch, P., Etxebarria, N., & Arana, G. (1997). Neutron activation analysis with k0-standardisation: general formalism and procedure. Applied Radiation and Isotopes, 48, 1275-1288. Page 27 of 29 [16] De Corte, F., & Simonits, A. (2003). Recommended nuclear data for use in the k0 standardization of neutron activation analysis. Atomic Data and Nuclear Data Tables, 85, 47-65. [17] De Corte, F. D. (1987). The k0-standardization method - a move to the optimization of NAA. Habilitation Thesis, University of Gent. [18] De Corte F., De Wispelaere A. (2005), "The use of a Zr-Au-Lu alloy for calibrating the irradiation facility in k0-NAA for general neutron spectrum monitoring", J. Radioanal. Nucl. Chem. 263, pp.653-657. [19] Eguskiza, M., Robouch, P., Wätjen, U., & De Corte, F. (2003). The preparation and homogeneity study of synthetic multi-element standards (SMELS) for QC/QA of k0-NAA. Journal of Radioanalytical and Nuclear Chemistry, 257, 669-676. [20] Vermaercke, P., Robouch, P., Eguskiza, M., De Corte, F., Kennedy, G., Smodiš, B., ... Lin, X. (2006). Characterisation of synthetic multi-element standards (SMELS) used for the validation of k0-NAA. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 564, 675-682. [21] Dung, H. M. (2016). Quality evaluation of the k0-standardized neutron activation analysis at the Dalat research reactor. Journal of Radioanalytical and Nuclear Chemistry, 309(1), 135-143. [22] Doanh, H. V., & Dung, H. M. (2018). The upgrading of the cyclic neutron activation analysis facility at the Dalat research reactor. Journal of Radioanalytical and Nuclear Chemistry, 315, 301-308. [23] Ho Manh Dung, Tran Quang Thien, Ho Van Doanh, Truong Truong Son, Phonesavanh Lathdavong, Development of a PC program for the k0‑based epithermal neutron activation analysis, Journal of Radioanalytical and Nuclear Chemistry, Volume 332 (2023) 3469–3474. [24] Vu, C. D., Thien, T., Doanh, H., Quyet, P., Anh, T., & Dien, N. (2014). Characterization of neutron spectrum parameters at irradiation channels for neutron activation analysis after full conversion of the Dalat nuclear research reactor to low enriched uranium fuel. Journal of Nuclear Science and Technology, Vol. 4(1), 70-75. [25] Farina Arboccò, F., Vermaercke, P., Smits, K., Sneyers, L., & Strijckmans, K. (2014). Experimental determination of k0, Q0 factors, effective resonance energies and neutron cross-sections for 37 isotopes of interest in NAA. Journal of Radioanalytical and Nuclear Chemistry, 302(1), 655-672. [26] De Corte, F., & Simonits, A. (1989). k0-Measurements and related nuclear data compilation for (n, γ) reactor neutron activation analysis: IIIb: tabulation. Journal of Radioanalytical and Nuclear Chemistry, 133, 43-130. [27] Arbocco, F. F., Vermaercke, P., Smits, K., Sneyers, L., Strijckmans, K. (2013). Experimental determination of k0, Q0, Er factors and neutron cross-sections for 41 isotopes of interest in Neutron Activation Analysis. J. Radioanal. Nucl. Chem., 296, 931-938. [28] Blaauw, M. (1994). The holistic analysis of gamma-ray spectra in instrumental neutron activation analysis. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 353(1-3), 269-271. Page 28 of 29 [29] Kučera, J., Kamenik, J., & Povinec, P. P. (2017). Radiochemical separation of mostly short-lived neutron activation products. Journal of Radioanalytical and Nuclear Chemistry, 311, 1299-1307. [30] Kučera, J., & Zeisler, R. (2004). Do we need radiochemical separation in activation analysis? Journal of radioanalytical and nuclear chemistry, 262(1), 255-260. [31] Kučera J., Řanda Z.: The present role of neutron and photon activation analysis in determination of trace elements. 3rd, 85 Symp. on Nuclear Chemistry, Halifax, NS, Canada, 11–14 June, 2001. [32] Use of research reactors for neutron activation analysis. IAEA-TECDOC- 1215, IAEA Vienna, 2001. [33] Currie, L. A. (1999). Detection and quantification limits: origins and historical overview. Analytica Chimica Acta, 391(2), 127-134. [34] Taskaeva, M., Taskaev, E., & Penev, I. (1996). On the preparation of efficiency calibration standards for gamma-ray spectrometers. Applied Radiation and Isotopes, 47, 981-990. [35] De Corte, F., Bellemans, F., De Neve, P., Simonits, A. (1994). The use of a modified Westcott-formalism in the ko-standardization of N The state of affairs. Journal of radioanalytical and nuclear chemistry, 179, 93-103. [36] De Corte, F., Simonits, A., De Wispelaere, A., & Hoste, J. (1987). Accuracy and applicability of the k0-standardization method. Journal of Radioanalytical and Nuclear Chemistry, 113(1), 145-161. [37] De Corte, F. et, al., (1972). In Book of Abstract, FOUR DECADES OF k0- NAA: AN APPRAISAL, Neutron Activation Analysis, 17, 115. [38] De Corte, F., & Simonits, A. (1994). Vademecum for k0-users. DMS Research, Geleen. [39] Ellison, S. L., & Williams, A. (2012). Quantifying uncertainty in analytical measurement. [40] Truong Truong Son, Ho Van Doanh, Ho Manh Dung, Determination of k0 factors of short-lived nuclides 46mSc and 110Ag for the k0-NAA, Journal of Nuclear Engineering and Technology, 55 (2023) 3202-3205. [41] IAEA (2020). The k0-database by k0-ISC 2020. [42] Farina Arboccò, F., Vermaercke, P., Smits, K., Sneyers, L., Strijckmans, K. (2014). Experimental determination of k0, Q0 factors, effective resonance energies and neutron cross-sections for 37 isotopes of interest in NAA. Journal of Radioanalytical and Nuclear Chemistry, 302, 655-672. [43] Acharya, R., Holzbecher, J., & Chatt, A. (2012). Determination of k0-factors of short-lived nuclides and application of k0-NAA to selected trace elements. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 680, 1-5. [44] D’Agostino, G., Di Luzio, M., & Oddone, M. (2018). An uncertainty spreadsheet for the k0-standardisation method in neutron activation analysis. Journal of Radioanalytical and Nuclear Chemistry, 318(2), 1261-1269. [45] Molnar, G. L., Revay, Z., & Szentmiklosi, L. (2003). New perspectives for very short-lived neutron activation analysis. Journal of Radioanalytical and Nuclear Chemistry, 255(2), 157-163. Page 29 of 29 [46] Acharya, R., Nair, A., Reddy, A., & Manohar, S. (2002). Validation of a neutron activation analysis method using k0-standardization. Applied Radiation and Isotopes, 57(3), 391-398. [47] Jaćimović, R., Stibilj, V. (2010). Determination of Q0 and k0 factors for 75Se and their validation using a known mass of Se on cellulose. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 622, 415-418. [48] Acharya, R., & Chatt, A. (2003). Characterization of the Dalhousie University SLOWPOKE-2 reactor for k0-NAA and application to medium-lived nuclides. Journal of Radioanalytical and Nuclear Chemistry, 257(3), 525- 529.2012 [49] Acharya, R., Swain, K., & Reddy, A. (2010). Analysis of SMELS and reference materials for validation of the k0-based internal mono-standard NAA method using in-situ detection efficiency. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 622, 411-414. [50] Alghem, L., Ramdhane, M., Khaled, S., & Akhal, T. (2006). The development and application of k0-standardization method of neutron activation analysis at Es-Salam research reactor. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol.556, 386-390.