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All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Nuclear Data Sheets for A=82☆

The evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reactions studies for all isobars, Z=28(Ni) to Z=42(Mo), with mass number A=82. For {sup 82}Ni not much is known other than its identification. Most of the new data, i.e., after the last NDS (2003Tu03), are based on compilations included in XUNDL. Contributions of the various compilers in XUNDL are gratefully acknowledged.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2014

Metallic beam development for the Facility for Rare Isotope Beam

The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will accelerate a primary ion beam to energies beyond 200 MeV/u using a superconducting RF linac and will reach a maximum beam power of 400 kW on the fragmentation target. The beam intensity needed from the ECR ion source is expected to be between 0.4 and 0.5 emA for most medium mass to heavy mass elements. Adding to the challenge of reaching the required intensity, an expanded list of primary beams of interest has been established based on the production rate and the number of isotope beams that could be produced with FRIB. We report here on the development done for some of the beam in the list including mercury (natural), molybdenum ({sup 98}Mo), and selenium ({sup 82}Ser)

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Results of the double beta decay experiment NEMO-3

The double beta decay experiment NEMO-3 has taken data from February 2003 to January 2011. The two-neutrino decay half lives were measured for seven different isotopes ({sup 100}Mo, {sup 82}Se, {sup 116}Cd, {sup 150}Nd, {sup 96}Zr, {sup 48}Ca and {sup 130}Te). No evidence for neutrinoless double beta decay is observed. The 0νββ half-life limits are found to be T{sub 1/2}{sup 0ν}({sup 100}Mo)>1.0×10{sup 24}yr(90%C.L.) and T{sub 1/2}{sup 0ν}({sup 82}Se)>3.2×10{sup 23}yr(90%C.L.)

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2013

Strategy of HPGe screening measurements in the SuperNEMO experiment

SuperNEMO is a double beta decay experiment that will use a tracko-calorimeter technique. The goal is to reach a sensitivity of T{sub 1/2}(0ν)>10{sup 26} y corresponding to an effective Majorana neutrino mass of 0.04-0.11 eV with 100 kg of {sup 82}Se. The general strategy of the HPGe screening measurements is described for the materials of the SuperNEMO demonstrator, regarding their radiopurity and their location. The two platforms, PRISNA and LSM, used for this screening are also briefly described.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

Search for 0ν2β of {sup 100}Mo by NEMO-3 and status of SuperNEMO

The NEMO-3 experiment was devoted to the research of the neutrinoless double beta decay and the precise measurement of the two-neutrino double beta decay of seven isotopes. The detector took data in the Laboratoire Souterrain de Modane (LSM) from 2003 to 2011. The unique combination of a 3D-tracker and a calorimeter allowed to fully reconstruct the double beta decay events topology and strongly reduces the backgrounds. This feature also permitted to characterize the remaining backgrounds in independent analysis channels. With an exposure of 34.7 kg·y of {sup 100}Mo no evidence for the 0ν2β signal has been found, yielding a limit for the light Majorana neutrino mass mechanism of T{sub 1/2}(0ν2β) > 1.1 10{sup 24} years (90 % C.L.) once both statistical and systematic uncertainties are taken into account. Depending on the Nuclear Matrix Elements this corresponds to an upper limit on the Majorana effective neutrino mass of |m{sub ββ}| < 0.3 − 0.9 eV (90 % C.L.). Constraints on other lepton number violating mechanisms of 0ν2β decays are also given. Searching for high-energy double electron events in all suitable sources of the detector, no event in the energy region [3.2-10] MeV is observed for an exposure of 47 kg·y. The next generation experiment, SuperNEMO, will use the same experimental technique to extend the sensitivity on the neutrinoless double beta decay search. Several aspects have been improved compared to NEMO-3: choice of the isotope, energy resolution, energy losses… but the main challenge is the background reduction. All the detector materials have been selected for their low natural radioactivity contaminations through High Purity Germanium (HPGe) gamma spectroscopy. The double beta sources after enrichment are being prepared with extreme care and the ultimate contaminations will be characterized by the most sensitive BiPo detector. External radon tightness and internal radon emanation have been studied to ensure a very low level in the tracker with very sensitive complementary detectors: diffusion apparatus, concentration line and emanation tanks. The construction of the first detector, called the demonstrator, has started in 2012. Studying 7 kg of {sup 82}Se, the demonstrator will reach the NEMO-3 sensitivity in only 5 months and improve it by at least a factor 6 in 2.5 years. Underground installation will start fall 2014 and physics data taking should start by summer 2015.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Average and recommended half-life values for two neutrino double beta decay: Upgrade-2013

All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of {sup 48}Ca, {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 100}Mo−{sup 100}Ru (0{sub 1}{sup +}), {sup 116}Cd, {sup 130}Te, {sup 136}Xe, {sup 150}Nd, {sup 150}Nd−{sup 150}Sm (0{sub 1}{sup +}) and {sup 238}U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of {sup 128}Te and {sup 130}Ba are proposed. I recommend the use of these results as the most currently reliable values for half-lives.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

CALDER: Cryogenic light detectors for background-free searches

The development of background-free detectors is essential for experiments searching for rare events. Bolometers, that are among the most competitive devices for the study of neutrino-less double beta decay (0νDBD) and Dark Matter interactions, suffer from the absence of techniques that allow to identify the nature of the interacting particles. This limit can be overcome by coupling the bolometer to an independent device for the measurement of the light emitted by interactions, as the combined read-out of the bolometric and light signals allows to identify and reject particles different from those of interest. CUORE, the most advanced bolometric experiment for 0νDBD searches, could disentangle the electrons produced by 0νDBD from the dangerous background due to α particles, by measuring the (tiny) Cherenkov light emitted by electrons and not by α’s. LUCIFER, a project based on ZnSe scintillating bolometers for the study of {sup 82}Se 0νDBD, would be competitive also in the search of Dark Matter interactions if equipped with light detectors that allow to distinguish and reject the background due to electrons and γ’s. These advances require cryogenic detectors characterized by noise lower than 20 eV, large active area, wide temperature range of operation, high radio-purity and ease in fabricating hundreds of channels. The CALDER collaboration aims to develop such detectors by exploiting the superb energy resolution and natural multiplexed read-out provided by Kinetic Inductance Detectors.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

Radon emanation based material measurement and selection for the SuperNEMO double beta experiment

The SuperNEMO Demonstrator experiment aims to study the neutrinoless double beta decay of 7 kg of {sup 82}Se in order to reach a limit on the light Majorana neutrino mass mechanism T{sub 1/2} (ββ0ν) > 6.5 10{sup 24} years (90%CL) equivalent to a mass sensitivity mβ{sub β} < 0.20 - 0.40 eV (90%CL) in two years of data taking. The detector construction started in 2014 and its installation in the Laboratoire Souterrain de Modane (LSM) is expected during the course of 2015. The remaining level of {sup 226}Ra ({sup 238}U chain) in the detector components can lead to the emanation of {sup 222}Rn gas. This isotope should be controlled and reduced down to the level of a 150 µBq/m{sup 3} in the tracker chamber of the detector to achieve the physics goals. Besides the HPGe selection of the detector materials for their radiopurity, the most critical materials have been tested and selected in a dedicated setup facility able to measure their {sup 222}Rn emanation level. The operating principle relies on a large emanation tank (0.7m{sup 3}) that allows measuring large material surfaces or large number of construction pieces. The emanation tank is coupled to an electrostatic detector equipped with a silicon diode to perform the alpha spectroscopy of the gas it contains and extract the {sup 222}Rn daughters. The transfer efficiency and the detector efficiency have been carefully calibrated through different methods. The intrinsic background of the system allows one to measure 222Rn activities down to 3 mBq, leading to a typical emanation sensitivity of 20 µBq/m{sup 2}/day for a 30 m{sup 2} surface sample. Several construction materials have been measured and selected, such as nylon and aluminized Mylar films, photomultipliers and tracking of the SuperNEMO Demonstrator.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Neutrinoless double beta decay with 82 SeF 6 and direct ion imaging

Here, we present a new neutrinoless double beta decay concept: the high pressure selenium hexafluoride gas time projection chamber. A promising new detection technique is outlined which combines techniques pioneered in high pressure xenon gas, such as topological discrimination, with the high Q-value afforded by the double beta decay isotope 82 Se. The lack of free electrons in SeF6 mandates the use of an ion TPC. The microphysics of ion production and drift, which have many nuances, are explored. Background estimates are presented, suggesting that such a detector may achieve background indices of better than 1 count per ton per year in the region of interest at the 100 kg scale, and still better at the ton-scale.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Oxidation of Dissolved Tetravalent Selenium by Birnessite: Se Isotope Fractionation and the Effects of pH and Birnessite Structure

Redox reactions control the mobility and bioavailability of selenium (Se) in biogeochemical systems, both modern and ancient. Se isotope ratio measurements (e.g., 82 Se/ 76 Se) have been developed to enhance understanding of biogeochemical transformations and transport of Se. Stable isotope ratios of many elements are known to be powerful indicators of redox reactions, and shifts in 82 Se/ 76 Se have been observed for Se reduction reactions. However, Se isotope shifts caused by naturally relevant oxidation reactions have not been published. Here, we report Se isotope fractionation factors for oxidation of Se(IV) by birnessite. Experiments were conducted at pH = 4.0 and 5.5, with two types of birnessite of contrasting composition at two concentrations of suspended birnessite. The results are consistent with a single 82 Se/ 76 Se fractionation factor, for all times during all experiments, of 0.99767 (±0.0035 2 s.d.). Expressed as ε, the fractionation is 2.33‰ (±0.08‰).

58 GEOSCIENCES↗
DOE OSTI2013

OMC studies for the matrix elements in ββ decay

Energy and time spectra of gamma-rays following μ-capture in natural Kr, Se, Cd and Sm, as well as isotopic enriched {sup 82}Kr, {sup 76}Se, {sup 106}Cd and {sup 150}Sm, have been measured. Total life-times of muons in different isotopes, as well as partial μ-capture rates to the excited states of {sup 48}Sc, {sup 76}As and {sup 106}Ag, were extracted. These results are discussed in the context of the double-beta decay matrix elements. The data are also compared with data from theoretical calculations and with data from charge-exchange reactions on {sup 48}Ti. It is the first time that μ-capture and charge-exchange reaction data are being compared in the context of ββ decay.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2013

THE IMPACT OF HELIUM-BURNING REACTION RATES ON MASSIVE STAR EVOLUTION AND NUCLEOSYNTHESIS

We study the sensitivity of presupernova evolution and supernova nucleosynthesis yields of massive stars to variations of the helium-burning reaction rates within the range of their uncertainties. The current solar abundances from Lodders are used for the initial stellar composition. We compute a grid of 12 initial stellar masses and 176 models per stellar mass to explore the effects of independently varying the {sup 12}C({alpha}, {gamma}){sup 16}O and 3{alpha} reaction rates, denoted R{sub {alpha},12} and R{sub 3{alpha}}, respectively. The production factors of both the intermediate-mass elements (A = 16-40) and the s-only isotopes along the weak s-process path ({sup 70}Ge, {sup 76}Se, {sup 80}Kr, {sup 82}Kr, {sup 86}Sr, and {sup 87}Sr) were found to be in reasonable agreement with predictions for variations of R{sub 3{alpha}} and R{sub {alpha},12} of {+-}25%; the s-only isotopes, however, tend to favor higher values of R{sub 3{alpha}} than the intermediate-mass isotopes. The experimental uncertainty (one standard deviation) in R{sub 3{alpha}}(R{sub {alpha},12}) is approximately {+-}10%({+-}25%). The results show that a more accurate measurement of one of these rates would decrease the uncertainty in the other as inferred from the present calculations. We also observe sharp changes in production factors and standard deviations for small changes in the reaction rates, due to differences in the convection structure of the star. The compactness parameter was used to assess which models would likely explode as successful supernovae, and hence contribute explosive nucleosynthesis yields. We also provide the approximate remnant masses for each model and the carbon mass fractions at the end of core-helium burning as a key parameter for later evolution stages.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

High energy-resolution measurement of the Se 82 ( He 3 , t ) Br 82 reaction for double- β decay and for solar neutrinos

For this study, a high-resolution ( 3 He,t) charge-exchange experiment at an incident energy of 420 MeV has been performed on the double beta (ββ) decay nucleus 82 Se. A detailed Gamow-Teller (GT - ) strength distribution in 82 Br has been extracted, which provides information to the ββ-decay nuclear matrix elements. Three strong and isolated transitions, which are to the 75, 1484 and the 2087 keV states in 82 Br, are found to dominate the low-excitation region below ≈ 2.1 MeV. Above 2.1 MeV a sudden onset of a strong GT fragmentation is observed. The degree of fragmentation resembles a situation found in the neighboring A = 76 system 76 Ge, whereas the observed concentration of strength in the three low-lying states is reminiscent of the heavier neighbors 96 Zr and 100 Mo. The strong GT transition to the 75 keV (1 + ) state makes 82 Se interesting for solar neutrino detection. The 82 Se(ν e ,e - ) 82 Br solar neutrino capture rate in a nonoscillation scenario is therefore evaluated to 668 ± 12(stat) ± 60(sys) SNU, and some of the advantages of using selenium for solar neutrino studies are discussed.

59 ≤ A ≤ 89↗
DOE OSTI2018

Defatted Microalgae-Mediated Enrichment of n–3 Polyunsaturated Fatty Acids in Chicken Muscle Is Not Affected by Dietary Selenium, Vitamin E, or Corn Oil

We previously showed enrichments of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in broiler chicks fed defatted microalgae. The aims of this study were to determine 1) if the enrichments affected meat texture and were enhanced by manipulating dietary corn oil, selenium, and vitamin E concentrations and 2) how the enrichments corroborated with hepatic gene expression involved in biosynthesis and oxidation of EPA and DHA. Day-old hatching Cornish Giant cockerels (n= 216) were divided into 6 groups (6 cages/group and 6 chicks/cage). Chicks were fed 1 of the 6 diets: a control diet containing 4% corn oil, 25 IU vitamin E/kg, and 0.2 mg Se/kg (4CO), 4CO + 10% microalgae (defatted Nannochloropsis oceanica; 4CO+ MA), 4CO+ MA – 2% corn oil (2CO+MA), 2CO+MA + 75 IU vitamin E/kg (2CO+MA+E), 2CO+MA + 0.3 mg Se/kg (2CO+MA+Se), and 2CO+MA+E + 0.3 mg Se/kg (2CO+MA+E+Se). After 6 wk, fatty acid profiles, DHA and EPA biosynthesis and oxidation, gene expression, lipid peroxidation, antioxidant status, and meat texture were measured in liver, muscles, or both. Compared with the control diet, defatted microalgae (4CO+MA) enriched (P< 0.05) DHA and EPA by ≤116 and 24 mg/100 g tissue in the liver and muscles, respectively, and downregulated (41–76%, P< 0.01) hepatic mRNA abundance of 4 cytochrome P450 (CYP) enzymes (CYP2C23b, CYP2D6, CYP3A5, CYP4V2). Supplemental microalgae decreased (50–82%, P< 0.05) lipid peroxidation and improved (16–28%, P< 0.05) antioxidant status in the liver, muscles, or both. Furthermore, the microalgae-mediated enrichments in the muscles were not elevated by altering dietary corn oil, vitamin E, or selenium and did not affect meat texture. The microalgae-mediated enrichments of DHA and EPA in the chicken muscles were associated with decreased hepatic gene expression of their oxidation, but were not further enhanced by altering dietary corn oil, vitamin E, or selenium.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Data Validation Package October 2015 Groundwater and Surface Water Sampling at the Monticello, Utah, Processing Site January 2016

Sampling Period: October 12–14, 2015. This semiannual event includes sampling groundwater and surface water at the Monticello Mill Tailings Site. Sampling and analyses were conducted as specified in the 2004 Monticello Mill Tailings Site Operable Unit III Post-Record of Decision Monitoring Plan, Draft Final and Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). Samples were collected from 52 of 61 planned locations (15 of 17 former mill site wells, 17 of 18 downgradient wells, 9 of 9 downgradient permeable reactive barrier wells, 2 of 7 seeps and wetlands, and 9 of 10 surface water locations). Locations MW00-07, Seep 1, Seep 2, Seep 3, Seep 5, Seep 6, SW00-01, T01-13, and T01-19 were not sampled because of insufficient water availability. All samples were filtered as specified in the monitoring plan. Duplicate samples were collected from surface water location W3-04 and from monitoring wells 82-08, 92-09, and 92-10. Water levels were measured at all but one sampled well and an additional set of wells. The contaminants of concern (COCs) for the Monticello Mill Tailings Site are arsenic, manganese, molybdenum, nitrate + nitrite as nitrogen (nitrate + nitrite as N), selenium, uranium, and vanadium. Time-concentration graphs of the COCs for all groundwater and surface water locations are included in this report. Locations with COCs that exceeded remediation goals are listed.

2015 Monticello↗
DOE OSTI2024

Development of selenium imaging detectors toward a definitive search for neutrinoless ββ decay

Imaging sensors made from an ionization target layer of amorphous selenium (aSe) coupled to a silicon complementary metal-oxide-semiconductor (CMOS) active pixel array for charge readout are a promising technology for neutrino physics. The high spatial resolution in a solid-state target provides unparalleled rejection of backgrounds from natural radioactivity in the search for the neutrinoless ββ decay of 82 Se. With this grant, we experimentally determined two crucial factors necessary for the realization of this novel technology: i) the intrinsic energy response of aSe to ionizing electrons, and ii) the feasibility to couple a target layer of aSe to a CMOS active pixel sensor to image electron tracks.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Inorganic resins enable the increased purification efficiency of 82 Sr from rubidium targets for use in PET imaging isotope production

The 82 Sr/ 82 Rb generator system has found use in positron emission tomography (PET) imaging of myocardial perfusion. 82 Sr is produced by proton irradiation of Rb metal/RbCl salt followed by chemical separation. Inorganic ion-exchangers were synthesized by hydrothermal methods and evaluated for the purification of accelerator-produced 82Sr from a RbCl target and co-produced impurities like 75 Se, Fe, Cr, and Ni. A process consisting of removal of bulk RbCl using sodium nonatitanate (SNT), then removal of remaining tracers of Rb and Se using poorly crystalline silicotitanate (pCST) is suitable for 82 Sr separation and achieves higher purity of 82 Sr vs. commonly used organic resins.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

New detections of arsenic, selenium, and other heavy elements in two metal-poor stars

We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope to obtain new high-quality spectra covering the 1900 ≤λ ≤ 2360 Å wavelength range for two metal-poor stars, HD 108317 and HD 128279. We derive abundances of Cu II, Zn II, As I, Se I, Mo II, and Cd II, which have not been detected previously in either star. Abundances derived for Ge I, Te I, Os II, and Pt I confirm those derived from lines at longer wavelengths. We also derive upper limits from the non-detection of W II, Hg II, Pb II, and Bi I. The mean [As/Fe] ratio derived from these two stars and five others in the literature is unchanged over the metallicity range –2.8 < [Fe/H] <–0.6, ([As/Fe]) = +0.28 ± 0.14 (σ = 0.36 dex). The mean [Se/Fe] ratio derived from these two stars and six others in the literature is also constant, ([Se/Fe]) = +0.16 ± 0.09 (σ = 0.26 dex). The As and Se abundances are enhanced relative to a simple extrapolation of the iron-peak abundances to higher masses, suggesting that this mass region (75 ≤A ≤ 82) may be the point at which a different nucleosynthetic mechanism begins to dominate the quasi-equilibrium α-rich freezeout of the iron peak. ([Cu II/Cu I]) = +0.56 ± 0.23 in HD 108317 and HD 128279, and we infer that lines of Cu I may not be formed in local thermodynamic equilibrium in these stars. The [Zn/Fe], [Mo/Fe], [Cd/Fe], and [Os/Fe] ratios are also derived from neutral and ionized species, and each ratio pair agrees within the mutual uncertainties, which range from 0.15 to 0.52 dex.

79 ASTRONOMY AND ASTROPHYSICS↗