[en] The aim of this work is to update the coefficients of our empirical formula as a tool for quickly and better estimating the stopping range of different charged particles ranging in Z=2−103 at various energies from 2.5 to 500 AMeV in aluminum material. A graphical-user-interface computer code (SRC v1.0) was also programmed to execute the calculation based on the empirical model. The reliability of the common computer codes, SRIM2013 and ATIMA, was examined together with the empirical formula by comparing the computed results to the experimental data evaluated by Hubert et al. (Atom Data Nucl Data Tables 46:1–213, 1990) for the practical use. The ranges based on the empirical model computed using the self-developed SRC code with the updated coefficients are in an excellent agreement with the experimental data and better than those computed using the SRIM2013 and ATIMA codes. The maximum deviation of the empirical model from the evaluated measured database is only 3% while it is about 10% (or 15%) for the SRIM2013 (or ATIMA) code. The results of the present study are useful for radiation shielding and nuclear experiments at radioactive-isotope accelerator facilities

[en] The (n,2n) threshold reaction cross-sections, available in the literature are analysed for nuclei with 20≤Z≤92 in the neutron energy range of about 14.5 MeV. An empirical formula based on multiple regression technique is proposed for quick estimation of the (n,2n) reaction cross sections. The results obtained are compared with experimental data and those from other empirical formulae as long as by N-Z systematic. The validity of this formula is discussed. (author)

[en] The dependences of the depth and mass resolutions of analysis using Rutherford Backscattering Spectrometry (RBS) on some experimental conditions (such as the beam energy, the target tilting angle, etc.) have been investigated. A computer program for simulating the RBS spectra and for calculating the depth and mass resolution under different experimental conditions was developed. The results of calculation were experimentally checked by using some reference samples. The good agreements between calculated and experimental values have been found. The optimum analysis conditions over a wide range of RBS applications based on our calculation can be chosen. This investigation was conducted by using the RBS system at HUS 5SDH-2 Tandem accelerator at the Hanoi University of Science. (paper)

[en] A new empirical formula for quick estimation of range in beryllium material of charged particles with the charge number from 2 to 103 and with energy in the range from 2.5 to 500 MeV/nucleon has been given. This formula was found based on a table of ranges measured experimentally and calculated up to 1990. It is shown that the differences between the values calculated by our formula and the values tabulated in the table is less than about 2% for all ions in the whole energy range.

[en] Low-dose radiation stimulates plant growth, particularly in mosses, thereby enhancing their ability to absorb airborne elements using the moss bag technique. An experiment was conducted to investigate the effects of low-energy X-ray radiation (1-20 Gy, with a 1 Gy interval) on the growth of Babular indica moss. The results revealed that doses ranging from 2 Gy to 16 Gy improved moss growth compared to the non-irradiated control. The optimum stimulatory effect was observed at 14 Gy, as indicated by morphological characteristics, moss weight, and chlorophyll content. Consequently, 14 Gy was selected as the irradiation dose for moss in the monitoring environment. Analysis of element concentrations using Total Reflection X-ray Fluorescence (TXRF) demonstrated that the irradiated moss exhibited significantly improved element absorption compared to the non-irradiated moss, although still lower than that of natural moss. This study emphasizes that low-dose (14 Gy) radiation treatment of mosses holds promise as a solution for achieving more accurate results and a closer reflection of real air conditions in environmental monitoring using the moss bag technique. (author)

[en] The radioactivity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K natural radionuclides in Lao Portland cement samples were measured using a gamma-spectrometry with a HPGe detector. The activity concentrations were found to vary from 28.32 ± 2.23 to 65.50 ± 2.83 Bq kg-1 with a mean value of 41.12 ± 2.44 Bq kg^-1 for ²²⁶Ra; from 7.25 ± 2.00 to 44.01 ± 2.45 Bq kg^-1 with a mean of 16.60 ± 2.37 Bq kg^-1 for ²³²Th and from 49.19 ± 4.27 to 196.74 ± 4.75 Bq kg^-1 with a mean of 141.48 ± 4.50 Bq kg^-1 for ⁴⁰K, respectively. The radiological parameters were estimated to assess the potential radiological hazard including radium equivalent activity, total external absorbed dose rate in outdoor air at 1 m above the earth's surface, the annual effective dose, the gamma and alpha-indices were calculated using the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K. The results obtained in this study show no significant radiological hazards arising from using Lao Portland cement for building construction. (authors)

[en] Fragmentation of secondary beams of neutron-rich, unstable ^19,20,21O isotopes at beam energies near 600 MeV/nucleon was studied by measuring the production cross sections for carbon, nitrogen, and oxygen fragments. Data for stable ^17,18O beams were obtained as well. The measurements serve to illuminate the isospin dependence of the fragmentation process. The experimental results are compared to those from empirical parametrization and those from abrasion-ablation models

[en] A normalization procedure has been applied to improve the descriptive and predictive power of the enhanced generalized superfluid (EGS) model for the nuclear level density (NLD). In this procedure, the EGS model is normalized based on the experimental average level spacing at the neutron binding energy D${}_0$ and the cumulative number of experimental discrete levels in the low-energy region N(E). The values of normalization parameters are determined by systematically analyzing a set of 288 nuclei from ${}^{25}$Mg to ${}^{251}$Cf, whose experimental D${}_0$ and N(E) data are available. The systematical analysis permits to determine the values of the normalization parameters for any nucleus. The descriptive and predictive power of the normalized EGS (NEGS) model are demonstrated by making the comparison of the NEGS NLDs with the experimental NLD data of 70 nuclei obtained from the Oslo method. The results obtained show that the NEGS model describes reasonably well almost all the experimental NLDs and should be better used in the reaction codes than the conventional EGS, in particular for nuclei whose experimental NLDs are not available.

[en] After a brief review on low-energy RI beam production technology, nuclear astrophysics programs at CNS are presented including a scope of the field in the Wako campus. The CRIB project involves a total development of the whole facility to maximize the low-energy RI beam intensities, including the ion source, the AVF cyclotron and the low-energy RI beam separator CRIB, Some recent nuclear astrophysics experiments performed with the RI beams were discussed, including the measurement of the 14O(α,p)17F reaction, the key stellar reaction for the onset of the high-temperature rp-process. The first experiment performed with a newly installed high-resolution magnetic spectrograph PA of CNS was also presented. Collaboration possibilities for nuclear astrophysics in the RIKEN campus are also touched

[en] The role of nuclear clustering inreactions is discussed, with Cluster Nucleosynthesis Diagram (CND) proposed before, for nucleosynthesis in stellar evolution and explosive stellar phenomena. Special emphasis is placed on α-induced stellar reactions. We report here the first experimental evidence that a cluster resonances dominate the (α,p) stellar reaction cross sections that is crucial for the vp-process in core-collapse supernovae.