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Isotopes have been widely applied in a variety of scientific subjects; many aspects of isotopes, however, remain not well understood. In this study, I investigate the relation between the number of neutrons (N) and the number of protons (Z) in stable isotopes of non-radioactive elements and long-lived isotopes of radioactive elements at the double-linear scale (conventional Segrè chart) and the double-logarithmic scale. Statistical analyses show that N is a power-law function of Z for these isotopes: N = 0.73 x Z[sup 116]. This power-law relation provides better predictions for the numbers of neutrons in stable isotopes of nonradioactive elements and long-lived isotopes of radioactive elements than the linear relation on the conventional Segrè chart. The power-law pattern reveled here offers empirical guidance for probing long-lived isotopes of unknown radioactive elements. [ABSTRACT FROM AUTHOR]

The nuclear resonance vibrational spectroscopy (NRVS) measurements of the Fe vibrational density of states for one of the simplest porphyrins, Fe(II) octaethylporphyrin (FE(OEP)), are used to refine the force field for a normal-mode analysis. Better fits to the NRVS data might require explicit treatment of intermolecular forces, and NRVS measurements on single crystals of Fe(OEP) would further constrain the best-fit force field.

In this paper we discuss our experimental work in photoproducing two medically-useful radioisotopes (Zn(γ,p) Cu and Ca(γ,n)Ca → Sc) using an electron linear accelerator. We further address the issues of production and separation of medical isotopes arising from photoneutron (γ,n) and photoproton (γ,p) reactions. While (γ,n) reactions typically result in greater yields, separating product nuclides from the target is challenging since the chemical properties of both nuclides are identical. Although the yields of (γ,p) reactions are typically lower than for (γ,n), these proton-rich isotopes have the advantage that target and product nuclides belong to different chemical species allowing for more straightforward chemical separation. We conclude the paper by touching upon the dire necessity of experimentally revisiting a broad swath of photonuclear reactions in the 10- to 50-MeV regime. The very paucity of empirical cross-sectional data makes it altogether impossible to realistically predict accelerator-based photoproduction of many promising radiopharmaceuticals. [ABSTRACT FROM AUTHOR]

We performed computational and experimental studies of the feasibility of the gold bearing ore assay utilizing the Au(γ,n)Au photonuclear reaction. Gold bearing silicate samples were irradiated using bremsstrahlung produced by an electron accelerator with endpoint energies ranging from 25 to 40 MeV. Au yield simulations were benchmarked and experimental results were in good agreement with the predictions. Optimum electron beam energy for photon activation analysis was found to be around 32 MeV which corresponded to a detection limit of 80 ppb. Two-hour gamma-spectroscopy measurements were repeated every 24 h and the optimum sample cooling time was found to be about 100-160 h. [ABSTRACT FROM AUTHOR]

Abstract: We have used EML Surface Air Sampling Program (SASP) data to analyze the long-term trend in 7Be surface concentration and address possible correlation between this long-term trend and climatic changes, namely changes in precipitation patterns and temperature. In this paper we present 7Be concentration data from 23 sites, spanning over 25 years, all over the world, and extract long-term trend parameter using two independent techniques. The 7Be concentrations in most stations show a pronounced decreasing trend, potentially corresponding to statistically significant changes in transporting 7Be from upper atmosphere source to these sites. Weak negative correlation between 7Be concentration and amount of precipitation was also observed. However, more data from more representative sites around the world are needed the statistical robustness of this trend. [Copyright &y& Elsevier]

The 14th International Topical Meeting on Nuclear Applications of Accelerators (AccApp'21) was held in 2021 as an embedded topical meeting during the ANS Winter Meeting in Washington, D.C. The conference aimed to promote accelerator-based research and development and covered various research topics, including accelerator facilities, nuclear data, medical applications, and industrial applications. A total of 120 abstracts were submitted, and 105 presentations were given. The conference faced challenges due to the COVID-19 pandemic but was successful with the support of participants and sponsors. The conference proceedings were published in Nuclear Science and Engineering (NSE). [Extracted from the article]

Despite interesting properties, the use of 67 Cu, 186 Re and 47 Sc theranostic radionuclides in preclinical studies and clinical trials is curtailed by their limited availability due to a lack of widely established production methods. An IAEA Coordinated Research Project (CRP) was initiated to identify important technical issues related to the production and quality control of these emerging radionuclides and related radiopharmaceuticals, based on the request from IAEA Member States. The international team worked on targetry, separation, quality control and radiopharmaceutical aspects of the radionuclides obtained from research reactors and cyclotrons leading to preparation of a standard recommendations for all Member States. The CRP was initiated in 2016 with fourteen participants from thirteen Member States from four continents. Extraordinary results on the production, quality control and preclinical evaluation of selected radionuclides were reported in this project that was finalized in 2020. The outcomes, outputs and results of this project achieved by participating Member States are described in this minireview., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)