Evaluated Nuclear Structure Data File Research Articles

Half-life determination of the ground state decay of 167Tm and 168Tm

Precise determination of half-lives of 167Tm and 168Tm are important for their application in nuclear medicine diagnostics, nuclear forensics, and other nuclear data measurements. We produced 167Tm and 168Tm sources using an α-particle beam bombarded 165Ho target and a series purification steps. A series of 173 measurements was performed over a period of 44 days using a high-purity germanium (HPGe) detector to track the count rate change as a function of time by following the 207.8 keV and 531.5 keV γ-lines to determine the radioactive decay half-life of 167Tm. The measurement of half-life of 168Tm ground state has been performed using the same HPGe γ-ray spectrometer to observe γ-lines at 198.3 keV, 816.0 keV, 184.3 keV, 741.4 keV and 914.9 keV. Weighted least-squares fits of exponential decay curves were performed for the dataset of each γ-ray emission, with final determined half-lives of 9.250(15) d and 93.41(12) d for 167Tm and 168Tm, respectively. The uncertainty budgets are presented and discussed in detail. Our result of 167Tm half-life is consistent with the Evaluated Nuclear Structure Data File (ENSDF) recommended half-life of 9.25(2) d. The outcome of 168Tm half-life determination is longer than the ENSDF recommended half-life of 93.1(2) d. Further independent measurements would be ideal to resolve the discrepancy.

Development of nuclear de-excitation model EBITEM Ver.2

ABSTRACT The gamma de-excitation model of the general-purpose radiation transport code Particle and Heavy Ion Transport code System, called the Evaluated Nuclear Structure Data File (ENSDF)-Based Isomeric Transition and isomEr production Model (EBITEM) has been upgraded with a focus on precise neutron-capture reaction simulation. The first de-excitation subsequent to neutron capture of numerous nuclei, which was formerly simulated by a model based on the single particle model, is calculated using the Evaluated Gamma Activation File. The database used for further de-excitation, ENSDF, retrieved in 2013, was replaced with Reference Input Parameter Library 3 to consider internal conversion. The internal conversion process was interfaced with the atomic de-excitation model to assess the emission of Auger electrons and fluorescent X-rays. The spectra of gamma-rays from neutron-capture reactions calculated by the upgraded EBITEM correlate better with the evaluated cross-section data than those of the previous version.

PyEGAF: An open-source Python library for the Evaluated Gamma-ray Activation File

The Evaluated Gamma-ray Activation File (EGAF) is one of the most comprehensive resources for thermal neutron-capture data. This database contains data from prompt gamma activation analysis measurements carried out in a consistent manner using the same experimental configuration at the Budapest Research Reactor for 245 isotopes. Although these valuable datasets have been freely available for many years, one of the drawbacks is the outdated and cryptic Evaluated Nuclear Structure Data File (ENSDF) format that is currently adopted for dissemination, making it difficult for users unfamiliar with the format to access and utilize the data contained therein. Furthermore, the ENSDF format does not readily lend itself to modern computational technologies and a parser is required to interpret the complicated mixed-record format. To help overcome these challenges, we have developed a translator to convert the ENSDF-formatted datasets into an open standard JavaScript Object Notation (JSON) format enabling accessibility to applications using different programming languages running in different environments. To compliment this effort, we have also developed an open-source software package implemented in Python, pyEGAF, that is designed to interact with the JSON data structures for general purpose access, manipulation, and analysis of the neutron-capture γ-ray data in EGAF. The new format, together with the pyEGAF library, greatly enhances access to the wider applications community where EGAF data may be useful or is required.

Complete β -decay patterns of Cs142,Ba142, and La142 determined using total absorption spectroscopy

Background: The β decays of fission products produced in nuclear fuel are important for nuclear energy applications and fundamental science of reactor antineutrinos. In particular, nuclear reactor safety is related to the decay modes of radioactive neutron-rich nuclei, primarily via the emission of γ rays, neutrons, and electrons. Additionally nuclear reactors are the most powerful man-made source of antineutrinos emitted during the β decay of fission products. These antineutrinos are used to inspect fundamental properties of leptons as well as informing reactor operation. However, the majority of data on complex decays of fission products collected in the evaluated nuclear data repositories like Evaluated Nuclear Structure Data File (ENSDF) and Evaluated Nuclear Data Files (ENDF) are based on low-efficiency and often incomplete measurements resulting in questionable reference reactor antineutrino flux predictions, see the analysis by [Nichols, J. Nucl. Sci. Technol. 52, 17 (2015)]. Various assessments like the one done under the auspices of the [Yoshida et al., Assessment of Fission Product Decay Data for Decay Heat Calculations: A report by the Working Party on International Evaluation Co-operation of the Nuclear Energy Agency Nuclear Science Committee (Nuclear Energy Agency, Organization for Economic Co-operation and Development, Paris, France, 2007), Vol. 25], as well as by [Sonzogni, Johnson, and McCutchan, Phys. Rev. C 91, 011301(R) (2015)] and [Dwyer and Langford, Phys. Rev. Lett. 114, 012502 (2015)], list the A=142 isobars with high cumulative fission yield among the important nuclei where data for reactor decay heat and/or antineutrino production should be verified and/or improved. Purpose: Our goal is to improve the quality of β-decay measurements and evaluate the impact of modified decay schemes on reactor decay heat and antineutrino energy spectra, for fission products along the A=142 isobaric chain. This work is an in depth follow-up on [Rasco et al., Phys. Rev. Lett. 117, 092501 (2016)]. which presented briefly the impact of the corrected decay scheme of 142Cs. Here, we extend the data to full isobaric decay chain including the daughter nuclei, 142Ba and 142La, and present more details on the 142Cs results. Method: The decays of neutron-rich isobars of mass A=142 produced by means of proton-induced fission of U238 were measured using the Modular Total Absorption Spectrometer (MTAS) array on-line at the mass separator and Tandem accelerator at Oak Ridge National Laboratory. Results: The β-decay schemes for 142Cs and 142La were modified with respect to the nuclear data repositories. A small β-delayed neutron branching ratio for 142Cs emitter was remeasured as 0.10−3+5 %. Improved precision on the measured half-lives is reported. Small corrections to the low-energy decay of 142Ba are made. The β-decay patterns for 142La and 142Cs are presented. The decay heat release and cross section for the detection of reactor antineutrinos are deduced and compared to earlier results. Conclusions: The β-feeding pattern for 142Cs having decay energy value Qβ of over 7 MeV was substantially modified with respect to the current ENSDF entry. Smaller changes were encountered for 142La, but since this A=142 isobar also has a large cumulative yield in fission, the changes influence both decay heat and the antineutrino spectra. The previously known β intensities for 142Ba decay (Qβ value of 2.2 MeV) were verified and slightly modified. Overall, increased decay heat values and lower flux of antineutrinos interacting with matter are presented.12 MoreReceived 13 October 2022Accepted 14 February 2023DOI:https://doi.org/10.1103/PhysRevC.107.034303©2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeta decayFissionLifetimes & widthsNuclear reactorsNuclear structure & decaysProperties90 ≤ A ≤ 149TechniquesSpectrometers & spectroscopic techniquesNuclear Physics

A decay database of coincident γ−γ and γ−X-ray branching ratios for in-field spectroscopy applications

Current fieldable spectroscopy techniques often use single detector systems heavily impacted by interferences from intense background radiation fields. These effects result in low-confidence measurements that can lead to misinterpretation of the collected spectrum. To help improve interpretation of the fission products and short-lived radionuclides produced in a composite sample, a coincidence-database is being developed in support of a robust portable and X-ray coincidence detector system concurrently under development at the Pacific Northwest National Laboratory for in-field deployment. Hitherto, no database exists containing coincident γ−γ and γ−X-ray branching-ratio intensities on an absolute scale that will greatly enhance isotopic identification for in-field applications. As part of this project, software has been developed to parse all radioactive-decay data sets from the Evaluated Nuclear Structure Data File (ENSDF) archive to enable translation into a more useful JavaScript Object Notation (JSON) formats that more readily supports query-based data manipulation. The coincident database described in this work is the first of its kind and contains coincidence γ−γ and γ−X-ray intensities and their corresponding uncertainties, together with auxiliary metadata associated with each decay data set. The new JSON format provides a convenient and portable means of data storage that can be imported into analysis frameworks with relatively low overhead allowing for meaningful comparison with measured data.

Ongoing Updates to NNDC Web Services

The National Nuclear Data Center (NNDC) provides nuclear data through 40 websites, many of which are being updated to make data easier to find. The most visible change is a site-wide navigation menu that links to the NNDC’s most-visited databases. The Evaluated Nuclear Structure Data File (ENSDF) front page now also has a chart interface for visual exploration of its data. NuDat 3.0 provides a faster, smoother, and feature-rich interactive Chart of Nuclides. The Medical Internal Radiation Dose (MIRD) website has been updated with improved response times and decay diagrams. More recently, the NNDC has focused on standardizing its web development process. Through the use of Git version control and Gradle Build Tool, the NNDC intends to improve existing websites and guide the creation of new ones.

Systematic trends of 0[formula omitted], 1[formula omitted], 3[formula omitted] and 2[formula omitted] excited states in even-even nuclei

The spin and parity (Jπ) assignments in even-even nuclei were reviewed across the nuclear chart using the Evaluated Nuclear Structure Data File (ENSDF). The prevalence of 21+ first or lowest excited states is confirmed. The properties of 02+, 11−, and 31− lowest excited states were reexamined using the ENSDF data evaluation procedures. The Jπ systematic trends and correlations between level quantum numbers and nuclear physics phenomena are discussed.

Determination of β -decay feeding patterns of Rb88 and Kr88 using the Modular Total Absorption Spectrometer at ORNL HRIBF

Precise determination of ground-state feeding in the β decay of fission products is an important but challenging component in modeling reactor antineutrino flux and reactor decay heat. The Modular Total Absorption Spectrometer (MTAS) is a versatile NaI(Tl) detector array that determines the true β-decay pattern free from the pandemonium effect, including precise ground-state feeding intensities. In this paper, we report MTAS results of the β feeding intensities of Rb88 and Kr88, fission products with large cumulative yields in nuclear reactors. By comparing MTAS results with previous measurements, Rb88 provides a validation of MTAS's ability to determine ground-state feedings in β decays, while the precision of Kr88 ground-state feeding is improved when compared with the Evaluated Nuclear Structure Data File (ENSDF). The investigation of sources that contribute to β feeding branching uncertainties in MTAS experiments is discussed in detail. Lastly, the deconvolution of Rb88 decay spectra suggests that MTAS can distinguish an allowed β spectral shape from a first forbidden unique β spectral shape.1 MoreReceived 29 October 2021Accepted 15 April 2022DOI:https://doi.org/10.1103/PhysRevC.105.054312©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeta decayNuclear structure & decaysProperties59 ≤ A ≤ 89TechniquesNuclear data analysis & compilationSpectrometers & spectroscopic techniquesNuclear Physics

Two-step gamma cascade decays from the compound state to the ground state of 182Ta nucleus

Two-step gamma transitions corresponding to the decays from the compound state (6,062.93 keV) to the ground state of 182Ta nucleus have been investigated via a 181Ta(n,γ)182Ta reaction using the thermal neutron beam from the No.3 neutron channel of the Dalat Nuclear Research Reactor and a gamma-gamma coincidence spectrometer. By comparing with data extracted from the Evaluated Nuclear Structure Data File (ENSDF) library, the authors have determined the order of 20 pairs of gamma cascade transitions, and then constructed a corresponding partial nuclear level scheme of 182Ta. Based on the detected gamma transitions and levels, 17 primary transitions, 1 secondary transition, and 20 intermediate levels are found to be the same as those in the ENSDF. The remaining 3 primary transitions and 19 secondary transitions are, thus, considered as the new data. In addition, a tentative spin range of (2, 3, 4)ℏ. has been assigned to all the intermediate levels detected within the present work.

Level scheme of 164Dy obtained from 163Dy(n[formula omitted],2γ) experiment

This work presents the nuclear level scheme (NLS) of 164Dy nucleus obtained from the 163Dy(nth,2γ) experiment. The latter has used a γ−γ coincidence spectrometer to measure the two-step gamma cascades corresponding to the decays from the compound state to 9 low-lying states of 164Dy, whose energies are 0.0, 73.393, 242.234, 761.815, 828.215, 915.991, 976.916, 1039.309, and 1122.774 keV. Based on the measured data, the 164Dy NLS, which consists of 64 primary gamma transitions and their corresponding intermediate levels, together with 132 secondary gamma transitions, has been constructed. Among these data, 20 primary gamma transitions, 51 intermediate levels, and 63 secondary gamma transitions are found to be the same as those currently exist in the Evaluated Nuclear Structure Data File (ENSDF) database. The remaining data, which include 44 primary transitions, 13 intermediate levels, and 69 secondary transitions, are therefore, considered as an update for the NLS of 164Dy. In particular, the spin values of 57 observed intermediate levels have been tentatively assigned by means of transition rules. Furthermore, the influence of the present experimental data on the nuclear level density and radiative strength function is also discussed.

Texas A&M US Nuclear DATA Program

Nuclear data evaluation is an independent century-long expert activity accompanying the development of the nuclear physics science. Its goal is to produce periodic surveys of the world literature in order to recommend and maintain the set of the best nuclear data parameters of common use in all basic and applied sciences. After WWII the effort extended and while it became more international it continued to be supported mainly by the US for the benefit of the whole world. The Evaluated Nuclear Structure Data File (ENSDF) is the most comprehensive nuclear structure database worldwide maintained by the United States National Nuclear Data Center(NNDC)at Brookhaven National Laboratory(BNL)and echoed by the IAEA Vienna Nuclear Data Services. Part of the US Nuclear Data Program since 2005 the Cyclotron Institute is one of the important contributors to ENSDF. Since 2018 we became an international evaluation center working in a consortium of peers hosted traditionally by prestigious national institutes as well as universities. In this paper the main stages of the evaluation work are presented in order to facilitate a basic understanding of the process as a guide for our potential users. Our goals are to maintain a good productivity vs. quality performance assuring the currency of the data and participating in the effort of modernizing the structure of ENSDF databases in order to make them compatible with the data-centric paradigms of the future.

International network of nuclear structure and decay data evaluators

Compilation, evaluation and dissemination of nuclear data are arduous tasks that rely on contributions from experts in both the basic and applied sciences communities whose efforts are coordinated by the International Atomic Energy Agency (IAEA). The Evaluated Nuclear Structure Data File (ENSDF) includes the most extensive and comprehensive set of nuclear structure and decay data evaluations performed by the international network of Nuclear Structure and Decay Data evaluators (NSDD) under the auspices of the IAEA. In this report we describe the recent NSDD activities supported by the IAEA and provide some future perspectives.

Level scheme of Sm153 obtained from the Sm152(nth,γ) reaction using a γ−γ coincidence spectrometer

The level scheme of the compound $^{153}\mathrm{Sm}$ nucleus formed via the $^{152}\mathrm{Sm}({n}_{\text{th}},\ensuremath{\gamma})$ reaction is studied by using a $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence spectrometer at Dalat Nuclear Research Institute, Vietnam. All the $\ensuremath{\gamma}$ cascades, which correspond to the decays from the compound state to 12 final levels of 0 (${\frac{3}{2}}^{+}$), 7.535 (${\frac{5}{2}}^{+}$), 35.844 (${\frac{3}{2}}^{\ensuremath{-}}$), 90.875 (${\frac{5}{2}}^{\ensuremath{-}}$), 126.412 (${\frac{1}{2}}^{\ensuremath{-}}$), 127.298 (${\frac{3}{2}}^{\ensuremath{-}}$), 182.902 (${\frac{5}{2}}^{\ensuremath{-}}$), 321.113 (${\frac{3}{2}}^{+}$), 404.129 (${\frac{1}{2}}^{\ensuremath{-}}$), 405.470 (${\frac{3}{2}}^{\ensuremath{-}}$), 414.924 (${\frac{1}{2}}^{+}$), and 481.088 (${\frac{3}{2}}^{+}$) keV, have been measured. A total number of 386 cascades corresponding to 576 $\ensuremath{\gamma}$ transitions has been detected. Among these cascades, 103 primary $\ensuremath{\gamma}$ transitions together with their corresponding intermediate levels and 299 secondary transitions have been determined. In addition, 29 primary $\ensuremath{\gamma}$ transitions, 42 intermediate levels, and 8 secondary transitions have been found to be the same as those extracted from the Evaluated Nuclear Structure Data File (ENSDF) data. The remaining 74 primary $\ensuremath{\gamma}$ transitions, 61 intermediate levels, and 291 secondary transitions are therefore considered as new data. In particular, based on an assumption that most of the transitions are dipole, we have tentatively assigned the unique spin value of $\frac{3}{2}\ensuremath{\hbar}$ for 53 observed intermediate levels corresponding to the cascades from the compound state to the final levels of 7.535 (${\frac{5}{2}}^{+}$), 90.875 (${\frac{5}{2}}^{\ensuremath{-}}$), and 182.902 (${\frac{5}{2}}^{\ensuremath{-}}$) keV, whereas the remaining levels are assigned with the spin values in the range of $[\frac{1}{2},\frac{3}{2}]\ensuremath{\hbar}$. Moreover, the total and partial (for the spin range of $[\frac{1}{2},\frac{3}{2}]\ensuremath{\hbar}$) cumulative numbers of levels have been constructed by combining the ENSDF data with the new data obtained in the present experiment. Comparison between these new cumulative curves and those extracted from the nuclear level density (NLD) data, which are obtained using the Oslo method, shows that the maximum excitation energy ${E}_{\mathrm{max}}$, defined as the energy threshold below which most of the excited levels are observed, is extended to about 1.2 and 1.8 MeV for the total and partial NLD data, respectively. These values of ${E}_{\mathrm{max}}$ are higher than those obtained by using the present ENSDF data, which are around 1 MeV. The new cumulative curves have also been compared with different phenomenological and microscopic NLD models, and the recent exact pairing plus independent-particle model at finite temperature ($\mathrm{EP}+\mathrm{IPM}$), in which no fitting parameter has been employed, is found to be the best-fit one. The present findings provide updated information on the nuclear level structure and make a step toward the completed level schemes of excited compound nuclei.

Half-life determination of 77Kr using the reference source method

Samples of 77Kr were produced by (n, 2n) reaction with a DT accelerator, the decay of 77Kr has been tracked by the reference source method with three High-Purity Germanium (HPGe) detectors. Experimental data were recorded at regular time intervals during measurements covering more than 600 min. The determined half-life of 77Kr is 71.25 (42) min, which indicated that the most recent values reported in the 1970s and the value recommended by Evaluated Nuclear Structure Data File (ENSDF) may be biased.

Neutron inelastic scattering of 232Th: measurements and beyond

Gamma production cross sections have been obtained for 81 transitions in 232Th from (n,n’γ), 11 in 231Th from (n,2nγ) and 7 in 230Th from (n,3nγ) reactions using prompt gamma spectroscopy. Incident neutron energies were determined using the neutron time-of-flight technique. Sources of uncertainty have been examined and their correlations have been computed. Total uncertainty on cross sections ranges from 4 to 20%. Obtained cross sections are in agreement with prior experiments, but are not well reproduced by the TALYS 1.8 reaction code using default parameters. During analysis, discrepancies between our findings and the Evaluated Nuclear Structure Data File (ENSDF) were noted. Future work related to the present experiment includes: improving theoretical models, quantifying the influence of the 232Th inelastic neutron cross section on reactor core parameters, and conducting additional measurements.

Dose rate conversion parameters: Assessment of nuclear data

The dating of materials using stored dose methods requires accurate determination of the environmental dose rate. The calculation of dose rates from radionuclide concentrations requires conversion parameters derived from nuclear data (half life, decay energies and intensities, and branching ratios). With the substantial body of primary data, it is convenient to use data from evaluated libraries. These libraries show variations reflecting both newer data unavailable to earlier evaluations and the relative importance given to different data sets by the evaluators. Commonly used conversion parameters derive from the Evaluated Nuclear Structure Data File (ENSDF), either directly or from secondary publications, with new tabulations produced in recent years following revisions to this library. Other international evaluations of nuclear data include the NEA/OECD supported JEF2.2 and JEFF3.11 evaluations, and the Decay Data Evaluation Project (DDEP). A technique comparing different evaluations to identify data that can not be confidently used has been developed. These differences have been investigated with an evaluation of underlying nuclear data. Particular radionuclides of interest are discussed; 214Bi where recent evaluations depend on a single high precision data set, 228Ac where the decay scheme is incomplete and further measurements are required, and 40K where the mean beta energy has been calculated in the evaluations using an incorrect shape factor. Revised dose rate conversion factors have been produced, which are largely consistent with earlier values with the exception of the 40K beta parameter which is 4% higher than recent values but consistent with earlier calculations.

Complete β -decay pattern for the high-priority decay-heat isotopes I137 and Xe137 determined using total absorption spectroscopy

Background: An assessment done under the auspices of the Nuclear Energy Agency in 2007 suggested that the $\ensuremath{\beta}$ decays of abundant fission products in nuclear reactors may be incomplete. Many of the nuclei are potentially affected by the so called pandemonium effect and their $\ensuremath{\beta}\text{\ensuremath{-}}\ensuremath{\gamma}$ decay heat should be restudied using the total absorption technique. The fission products $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ were assigned highest priority for restudy due to their large cumulative fission branching fractions. In addition, measuring $\ensuremath{\beta}$-delayed neutron emission probabilities is challenging and any new technique for measuring the $\ensuremath{\beta}$-neutron spectrum and the $\ensuremath{\beta}$-delayed neutron emission probabilities is an important addition to nuclear physics experimental techniques.Purpose: To obtain the complete $\ensuremath{\beta}$-decay pattern of $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ and determine their consequences for reactor decay heat and ${\overline{\ensuremath{\nu}}}_{e}$ emission. Complete $\ensuremath{\beta}$-decay feeding includes ground state to ground state $\ensuremath{\beta}$ feeding with no associated $\ensuremath{\gamma}$ rays, ground state to excited states $\ensuremath{\beta}$ transitions followed by $\ensuremath{\gamma}$ transitions to the daughter nucleus ground state, and $\ensuremath{\beta}$-delayed neutron emission from the daughter nucleus in the case of $^{137}\mathrm{I}$.Method: We measured the complete $\ensuremath{\beta}$-decay intensities of $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ with the Modular Total Absorption Spectrometer at Oak Ridge National Laboratory. We describe a technique for measuring the $\ensuremath{\beta}$-delayed neutron energy spectrum, which also provides a measurement of the $\ensuremath{\beta}$-neutron branching ratio, ${P}_{n}$.Results: We validate the current Evaluated Nuclear Structure Data File (ENSDF) evaluation of $^{137}\mathrm{Xe}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$ decay. We find that major changes to the current ENSDF assessment of $^{137}\mathrm{I}\ensuremath{\beta}$-decay intensity are required. The average $\ensuremath{\gamma}$ energy per $\ensuremath{\beta}$ decay for $^{137}\mathrm{I}\ensuremath{\beta}$ decay ($\ensuremath{\gamma}$ decay heat) increases by 19%, from 1050--1250 keV, which increases the average $\ensuremath{\gamma}$ energy per $^{235}\mathrm{U}$ fission by $0.11%$. We measure a $\ensuremath{\beta}$-delayed neutron branching fraction for $^{137}\mathrm{I}\ensuremath{\beta}$ decay of $7.9\ifmmode\pm\else\textpm\fi{}0.2(\mathrm{fit})\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{sys})%$ and we provide a $\ensuremath{\beta}$-neutron energy spectrum.Conclusions: The Modular Total Absorption Spectrometer measurements of $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ demonstrate the importance of revisiting and remeasuring complex $\ensuremath{\beta}$-decaying fission products with total absorption spectroscopy. We demonstrate the ability of the Modular Total Absorption Spectrometer to measure $\ensuremath{\beta}$-delayed neutron energy spectra.

The Decay Data Evaluation Project (DDEP) and the JEFF-3.3 radioactive decay data library: Combining international collaborative efforts on evaluated decay data

The Decay Data Evaluation Project (DDEP), is an international collaboration of decay data evaluators formed with groups from France, Germany, USA, China, Romania, Russia, Spain and the UK, mainly from the metrology community. DDEP members have evaluated over 220 radionuclides, following an agreed upon methodology, including a peer review. Evaluations include all relevant parameters relating to the nuclear decay and the associated atomic processes. An important output of these evaluations are recommendations for new measurements, which can serve as a basis for future measurement programmes. Recently evaluated radionuclides include: 18 F, 59 Fe, 82 Rb, 82 Sr, 88 Y, 90 Y, 89 Zr, 94m Tc, 109 Cd, 133 Ba, 140 Ba, 140 La, 151 Sm and 169 Er. The DDEP recommended data have recently been incorporated into the JEFF-3.3 Radioactive Decay Data Library. Other sources of nuclear data include 900 or so radionuclides converted from the Evaluated Nuclear Structure Data File (ENSDF), 500 from two UK libraries (UKPADD6.12 and UKHEDD2.6), the IAEA Actinide Decay Data Library, with the remainder converted from the NUBASE evaluation of nuclear properties. Mean decay energies for a number of radionuclides determined from total absorption gamma-ray spectroscopy (TAGS) have also been included, as well as more recent European results from TAGS measurements performed at the University of Jyvaskyla by groups from the University of Valencia, Spain and SUBATECH, the University of Nantes, France. The current status of the DDEP collaboration and the JEFF Radioactive Decay Data Library will be presented.

New neutrino source for the study of solar neutrino physics in the vacuum-matter transition region

Production of a neutrino source through proton induced reaction is studied by using the particle transport code, GEANT4. Unstable isotope such as $^{27}$Si can be produced when $^{27}$Al target is bombarded by 15 MeV energetic proton beams. Through the beta decay process of the unstable isotope, a new electron-neutrino source in the 1.0 $\sim$ 5.0 MeV energy range is obtained. Proton induced reactions are simulated with JENDL High Energy File 2007 (JENDL/HE-2007) data and other nuclear data. For radioactive decay processes, we use "G4RadioactiveDecay" model based on the Evaluated Nuclear Structure Data File (ENSDF). We suggest target systems required for future's solar neutrino experiments, in particular, for the vacuum-matter transition region. As for the detection system of the new neutrino source, we evaluate reaction rates for available radiochemical detectors and LENA type scintillator detector. Possibility of detecting sterile neutrinos is also discussed.

Evolving landscape of low-energy nuclear physics publications

Evolution of low-energy nuclear physics publications over the last 120 years has been analyzed using nuclear physics databases. An extensive study of Nuclear Science References, Experimental Nuclear Reaction Data (EXFOR), and Evaluated Nuclear Structure Data File (ENSDF) contents provides a unique picture of refereed and non-refereed nuclear physics references. Significant fractional contributions of non-refereed reports, private communications and conference proceedings in EXFOR and ENSDF databases in the 1970's reflect extensive experimental campaigns and an insufficient number of research journals. This trend has been reversed in recent years because the number of measurements is much lower, while number of journals is higher. In addition, nuclear physics results are mainly published in a limited number of journals, such as Physical Review C and Nuclear Physics A. In the present work, historic publication trends and averages have been extracted and analyzed using nuclear data mining techniques. The results of this study and implications are discussed and conclusions presented.