(Received 2025; April 2026) Abstract: This work presents a comprehensive and critical evaluation of experimental nuclear spectroscopic data from reactions and decays for all 11 known nuclides with mass number 35 (Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca). Recommended values are produced for level energies, spins and parities, half-lives, and radiation properties including energies, branching ratios, and multipolarities of y rays, as well as characteristics of /3 radiation decays, based on a rigorous assessment of all available experimental data. Discrepancies among existing results are carefully addressed. This work supersedes earlier full evaluations of A=35 published by 2011Ch48, 1990En08 (also 1998En04 update) and 1978En02.
The integral gamma and electron spectra emitted by fission products, also known as delayed gamma and electron spectra, were measured at Oak Ridge National Laboratory in the 1970s for the thermal-neutron induced fission of 235U and 239,241Pu. Scintillator detectors were used to measure these spectra, data used later on to obtain decay heat values - that is, the spectra mean values per unit time as function of time - work that was published in the Nuclear Science and Technology journal; the spectral data, however, was only published in laboratory reports. In this work, we analyze the gamma spectra data using modern methods and nuclear databases to reveal the signature of individual fission products as well as to gauge the performance of the ENDF/B-VIII.0 decay data sub-library, concluding about possible future enhancements in predictive capabilities.
The Nuclear Data Sheets for A=261 (1999Ar21)and A=265 (1999Ar21) and a part of (2000Fi12) have been revised using experimental decay and reaction data received by January 1, 2018.
Experimental data from reaction and decay studies on nuclei with A=216 have been reviewed. Elements included in this review span from mercury (Z=80) to uranium (Z=92). Based on the published data, level and decay schemes are presented for the evaluated nuclides. This work updates and supersedes the previous A=216 evaluation (2007Wu02).
Experimental data pertaining to all nuclei with mass number A=169 (Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt) have been evaluated. Level schemes from both radioactive decay and reaction studies are presented, along with associated tables of experimental data and adopted properties for levels and gamma rays. The present evaluation for A=169 supersedes the 2008 evaluation, 2008Ba31, by C.M. Baglin. A few highlights of this evaluation: More extensive work on s decay from 169W is needed and new experimental work will be required to resolve a discrepancy between the J " values deduced for a 180-keV level in 169 Ta based on extensive band structure from (HI,xn gamma) work (J"=1/2-) and TDPAD measurements (J=5/2). Low lying states of 169 Os were studied via fine structure of 173 Pt alpha decay in 2014ThZZ. The E alpha s feeding the g.s. of 169 Os in 2008Ba31 are separated well into two consistent groups to feed the g.s. and the newly proposed state at 34.84 keV. Based on the studies of 2014ThZZ and 2021Zh52, the g.s. spin-parity assignment of 169 Os has been proposed to be (7/2-) from (5/2-). The 169 Ir g.s. half-life and alpha emission branching reported in 2012Th13 from 173 Au alpha decay measurements are preferred over the values in 2005Sc22. The reported half-life value in 2005Sc22 for 169 Ir g.s. is discrepant and the research work was carried out in the same lab of 2012Th13.
The Nuclear Data Sheets for A=261 (1999Ar21) and A=265 (1999Ar21) and a part of (2000Fi12) have been revised using experimental decay and reaction data received by January 1, 2018.
Evaluated nuclear structure and decay data for all nuclei with mass number A=229 (At-229, Rn-229, Fr-229, Ra-229, Ac-229, Th-229, Pa-229, U-229,Np-229, Pu-229, and Am-229) are presented. All available experimental data are compiled and evaluated, and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities and transition probabilities, as well as other nuclear properties, are recommended. Inconsistencies and discrepancies that exist in the literature are discussed. A number of computer codes (https://wwwnds.iaea.org/public/ensdf pgm/) developed by members of the NSDD network were used during the evaluation process. This work supersedes the earlier evaluation by E. Browne and J.K. Tuli (2008Br17), published in Nuclear Data Sheets 109, 2657 (2008).
Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for all nuclei with mass number A=234. This evaluation for A=234 supersedes the earlier one by E. Browne and J.K. Tuli (2007Br04), published in Nuclear Data Sheets 108, 681 (2007).
The ENDF/B-VIII.1 library is the newest recommended evaluated nuclear data file by the Cross Section EvaluationWorking Group (CSEWG) for use in nuclear science and technology applications, and incorporates advances made in the six years since the release of ENDF/B-VIII.0. Among key advances made are that the Pu-239 file was reevaluated by a joint international effort and that updated O-16,O-18, F-19, Si28-30, Cr50-54, Mn-55, Fe-54,Fe-56,Fe-57, Cu-63,Cu-65, La-139, U-233,U-235,U-238, and Pu-240,Pu-241 neutron nuclear data from the IAEA coordinated INDEN collaboration were adopted. Over 60 neutron dosimetry cross sections were adopted from the IAEA's IRDFF-II library. In addition, the new library includes significant changes for He-3, Li-6, Be-9, V-51, Sr-88, Rh-103, Ce-140,Ce-142, Dy, Ta-181, Pt, Pb206-208, and U-234,U-236 neutron data, and new nuclear data for the photonuclear, charged-particle and atomic sublibraries. Numerous thermal neutron scattering kernels were reevaluated or provided for the very first time. On the covariance side, work was undertaken to introduce better uncertainty quantification standards and testing for nuclear data covariances. The significant effort to reevaluate important nuclides has reduced bias in the simulations of many integral experiments with particular progress noted for fluorine, copper, and stainless steel containing benchmarks. Data issues hindered the successful deployment of the previous ENDF/B-VIII.0 for commercial nuclear power applications in high burnup situations. These issues were addressed by improving the 238U and 239,240,241Pu evaluated data in the resonance region. The new library performance as a function of burnup is similar to the reference ENDF/B-VII.1 library. The ENDF/B-VIII.1 data are available in ENDF-6 and GNDS format at https://doi.org/10.11578/endf/2571019.
The experimental nuclear structure data available through October 2013 have been reviewed. A summary of information obtained in various reaction and decay experiments is presented, together with adopted level schemes.
Experimental data on ground-and excited-state properties for all known nuclei with mass number A=69 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given in detail. This work supersedes the 2013 evaluation by C.D.Nesaraja (2014Ne01).
The experimental reaction and decay studies producing nuclei in the A=240 mass chain have been reviewed. Data on elements from uranium (Z=92) to einsteinium (Z=99) are included, and level and decay schemes are presented for these nuclides. This work supersedes the previous evaluation for this mass chain (2008Si25).
Nuclear structure data for 15 known nuclides of mass number 175 (Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg) have been evaluated, which supersedes the earlier work done by M. Shamsuzzoha Basunia (2004Ba89), published in Nuclear Data Sheets 102, 719 (2004).
Evaluated spectroscopic data and level schemes are presented for 25N (unobserved), 25O, 25F, 25Ne, 25Na, 25Mg, 25Al, 25Si, and 25P based on the measured decay and nuclear reaction studies. This evaluation for A=25 supersedes the earlier one by R.B. Firestone (2009Fi05). Overall the decay datasets associated with 25Ne, 25Na, and 25Mg remain the same compared with those in the previous evaluation, 2009Fi05, however, new beta-n decay datasets are added in 25Ne along with new reaction datasets almost for all of the above mentioned nuclides from older and new references. Other highlights of this evaluation are the following: Ground state of 25O is neutron unbound. Several new articles reported resonance energies of this nuclide, studied using radioactive beams, like 24O,27Ne, 26F, etc. These results have been included in this evaluation. Due to the lack of direct experimental evidence, a tentative (5/2+) assignment for the ground state and no spin-parity assignments for the known excited states of 25Si has been adopted in the present evaluation. In the absence of experimental evidence, tentative (1/2+) assignment has been adopted for the ground state of 25P. As suggested in 2015Fe02, light-ion scattering experiment in the inverse kinematics seems to be a probable probe for investigating the low-lying states of 25P, which are the mirror analogs of the states of 25Ne.
Experimental nuclear spectroscopic data are evaluated for 12 known nuclides of mass number A=62 (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge). Detailed evaluated information are presented for each reaction and decay. Recommended values combining all available data are provided for all the spectroscopic properties of each level, gamma-ray, and decay radiation. Following is the status of structure and decay information available for each of the nuclides. 62Sc: only the isotopic identification has been made, with unknown half-life of its g.s., and its decay scheme. 62Ti: half-life of the g.s. is unknown, but the first (2+) and (4+) states have been reported, the second at 1506 keV. 62V: information is available for only the ground state, its decay scheme is poorly known, with three gamma rays, and one level in 62Cr. 62Cr: only three excited states are known up to 1458 keV, with half-life of one excited state. Its decay scheme is poorly known, with five gamma rays and three levels in the daughter nucleus. 62Mn: two beta-decaying activities are known, but with poorly known decay schemes. Ten excited states are known up to 1531 keV, and up to J=(8), but with no half-life known for any of the excited states. 62Fe: 23 excited states are known up to 5475 keV, and up to 10+, with the half-lives known for only the first 2+ and 4+ states. Its decay scheme is poorly known with only one gamma ray and one level in 62Co. 62Co: two beta-decaying activities are known, with their decay decay schemes fairly well established. Large number of levels are up to 6950 keV, and up to (13+), but half-lives of only two excited states are known. 62Ni: stable nucleus with a large number of levels known up to 24.5 MeV excitation, and up to (24-). Half-lives of 30 excited states are known. 62Cu: a large number of levels are known up to 10.9 MeV excitation, and up to (14+), but half-lives known for only seven excited states. Its decay scheme is fairly well established. 62Zn: a rare nucleus with co-existence of many different types of structures: five superdeformed bands, 11 well-deformed bands, two terminating bands, and nine normal-deformed bands, up to an excitation energy of 42.5 MeV, and up to (35-), with half-lives known for 18 excited states. Its decay scheme is well established. 62Ga: many levels are known up to 16.8 MeV excitation, and up to (21+), but half-life of only one excited state is known. Its decay scheme is of special interest due to superallowed decay to 62Zn, and has been intensively pursued in recent works. 62Ge: only two possible excited states have been suggested up to 2285 keV, with no knowledge of their J pi values. Its decay scheme to 62Ga is fairly well known, with probable involvement of a superallowed decay. 62As: this nuclide has not been investigated, it is included only for completeness. 62Se: experimental search for this nuclide by 2016Bl05 did not yield any events, implying that this nucleus is likely unbound towards two-proton emission as theoretical S(2p)=-3290 keV (2019Mo01). This work supersedes data in earlier ENSDF evaluation of A=62 nuclei by 2012Ni08.
Available information pertaining to the nuclear structure of ground and excited states for all known nuclei with mass numbers A=248 has been compiled and evaluated. The adopted level and decay schemes, as well as the detailed nuclear properties and configuration assignments based on experimental data, are presented for these nuclides. When there are insufficient data, expected values from systematics of nuclear properties and/or theoretical calculations are utilized. Unexpected or discrepant experimental results are also noted. This work supersedes the 2014 evaluation by M.J. Martin (2014Ma86).
Experimental nuclear spectroscopic data are evaluated for 14 known nuclides of mass number A=86 (Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru). Detailed evaluated information is presented for each reaction and decay. Recommended values combining all available data are provided for the spectroscopic properties of each level, gamma-ray, and decay radiation. Limited level and gamma information is available for 86Ga (ground state and one excited level), 86Ge (six levels), and 86As (ten excited states), with their respective /3-decays poorly known. Fairly detailed level and gamma data are available for 86Se, 86Br, 86Kr, 86Rb, 86Sr and 86Y nuclei. The decay of 86Br to 86Kr has recently been studied by gamma spectroscopy (2016Ur04) and by TAGS technique (2017Ri08), the latter suggesting that many additional levels in 86Kr exist which have not been detected in high-resolution gamma-ray spectroscopy. The gamma-ray spectra in 2016Ur04 were valid up to E gamma=4 MeV, whereas the Q(/3) value of 7.63 MeV for 86Br permits population of high-energy levels. For 86Zr, 86Nb and 86Mo, the data are available for mostly the high-spin states, as the decays of 86Nb, 86Mo, and 86Tc, which could populate low-spin levels, are not known well. For 86Tc, only four levels are known from the decay of an isomeric activity in 86Tc. In addition, decay of 86Tc with g.s. J pi=(0+) to 0+ g.s. in 86Mo could involve superallowed /3 transition, which has been pursued experimentally in detail. For 86Ru only the isotopic identification is established, with its half-life and decay modes unknown. The evaluated data in this work supersede data in earlier ENSDF evaluation of A=86 nuclei by 2015Ne01, where the literature cutoff date was November 30, 2014.
Spectroscopic data for all nuclei with mass number A=47 have been evaluated and the corresponding level schemes from radioactive decay and reaction studies are presented. Highlights from this evaluation include first observation of gamma-ray transitions in 47Ar, a new high precision measurement of 47K beta decay, and first observation of excited levels and gamma-ray transitions in 47Mn.
The experimental results published before Aug 2022 from the various reaction and decay studies leading to nuclides of Z=56 to Z=72, 154Ba, 154La, 154Ce, 154Pr, 154Nd, 154Pm, 154Sm, 154Eu, 154Gd, 154Tb, 154Dy, 154Ho, 154Er, 154Tm, 154Yb, 154Lu, 154Hf, in the A=154 mass chain have been reviewed. These data are collected and presented in decay or reaction datasets, together with Adopted Levels and gammas datasets that are the most extensive collections of nuclear structure data for each nuclide. This work is intended to supersede the previous evaluation of the A=154 nuclides by C.W. Reich (2009Re14), which was published in Nuclear Data Sheets 110, 2257 (2009).
