Measurement of 139La(p,x) cross sections from 35–60 MeV by stacked-target activation

A stacked-target of natural lanthanum foils (99.9119% 139La) was irradiated using a 60 MeV proton beam at the LBNL 88-Inch Cyclotron. 139La(p,x) cross sections are reported between 35–60 MeV for nine product radionuclides. The primary motivation for this measurement was the need to quantify the production of 134Ce. As a positron-emitting analogue of the promising medical radionuclide 225Ac, 134Ce is desirable for in vivo applications of bio-distribution assays for this emerging radio-pharmaceutical. The results of this measurement were compared to the nuclear model codes TALYS, EMPIRE and ALICE (using default parameters), which showed significant deviation from the measured values

A structural evaluation of the tungsten isotopes via thermal neutron capture

Total radiative thermal neutron-capture $\gamma$-ray cross sections for the $^{182,183,184,186}$W isotopes were measured using guided neutron beams from the Budapest Research Reactor to induce prompt and delayed $\gamma$ rays from elemental and isotopically-enriched tungsten targets. These cross sections were determined from the sum of measured $\gamma$-ray cross sections feeding the ground state from low-lying levels below a cutoff energy, E$_{\rm crit}$, where the level scheme is completely known, and continuum $\gamma$ rays from levels above E$_{\rm crit}$, calculated using the Monte Carlo statistical-decay code DICEBOX. The new cross sections determined in this work for the tungsten nuclides are: $\sigma_{0}(^{182}{\rm W}) = 20.5(14)$ b and $\sigma_{11/2^{+}}(^{183}{\rm W}^{m}, 5.2 {\rm s}) = 0.177(18)$ b; $\sigma_{0}(^{183}{\rm W}) = 9.37(38)$ b and $\sigma_{5^{-}}(^{184}{\rm W}^{m}, 8.33 \mu{\rm s}) = 0.0247(55)$ b; $\sigma_{0}(^{184}{\rm W}) = 1.43(10)$ b and $\sigma_{11/2^{+}}(^{185}{\rm W}^{m}, 1.67 {\rm min}) = 0.0062(16)$ b; and, $\sigma_{0}(^{186}{\rm W}) = 33.33(62)$ b and $\sigma_{9/2^{+}}(^{187}{\rm W}^{m}, 1.38 \mu{\rm s}) = 0.400(16)$ b. These results are consistent with earlier measurements in the literature. The $^{186}$W cross section was also independently confirmed from an activation measurement, following the decay of $^{187}$W, yielding values for $\sigma_{0}(^{186}{\rm W})$ that are consistent with our prompt $\gamma$-ray measurement. The cross-section measurements were found to be insensitive to choice of level density or photon strength model, and only weakly dependent on E$_{\rm crit}$. Total radiative-capture widths calculated with DICEBOX showed much greater model dependence, however, the recommended values could be reproduced with selected model choices. The decay schemes for all tungsten isotopes were improved in these analyses.Comment: 25 pages, 15 figures, 15 table

Radioactive heat production of six geologically important nuclides

Heat production rates for the geologically important nuclides ${}^{26}$Al, ${}^{40}$K, ${}^{60}$Fe, ${}^{232}$Th, ${}^{235}$U, and ${}^{238}$U are calculated on the basis of recent data on atomic and nuclear properties. The revised data differ by several per cent from some older values, but indicate that more recent analyses converge toward values with an accuracy sufficient for all common geoscience applications, although some possibilities for improvement still remain, especially in the case of ${}^{40}$K and with regard to the determination of half-lives. A Python script is provided for calculating heat production (https://github.com/trg818/radheat).Comment: 14 pages, 1 figur

Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments

The Majorana Experiment will use arrays of enriched HPGe detectors to search for the neutrinoless double-beta decay of 76Ge. Such a decay, if found, would show lepton-number violation and confirm the Majorana nature of the neutrino. Searches for such rare events are hindered by obscuring backgrounds which must be understood and mitigated as much as possible. A potentially important background contribution to this and other double-beta decay experiments could come from decays of alpha-emitting isotopes in the 232Th and 238U decay chains on or near the surfaces of the detectors. An alpha particle emitted external to an HPGe crystal can lose energy before entering the active region of the detector, either in some external-bulk material or within the dead region of the crystal. The measured energy of the event will only correspond to a partial amount of the total kinetic energy of the alpha and might obscure the signal from neutrinoless double-beta decay. A test stand was built and measurements were performed to quantitatively assess this background. We present results from these measurements and compare them to simulations using Geant4. These results are then used to measure the alpha backgrounds in an underground detector in situ. We also make estimates of surface contamination tolerances for double-beta decay experiments using solid-state detectors.Comment: 10 pages, 11 figures, submitted to NIM

Nuclear Data Sheets for A=213

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for 213Hg, 213Tl, 213Pb, 213Bi, 213Po, 213At, 213Rn, 213Fr, 213Ra, 213Ac, 213Th, and 213Pa. This evaluation for A=213 supersedes the earlier one by the same evaluator, M. S. Basunia (2007Ba19), published in Nuclear Data Sheets 108, 633 (2007). One highlight of this evaluation is the following: In 213Po, from 208Pb(18O,Xγ) study 2011As05 proposed revision of spin-parity assignments for 293 level: 7/2+ instead of (11/2+); 440 level: 11/2+ instead of (7/2+); 868 level: 9/2+ instead of (13/2+). New experiments are needed

Best-fitted mathematical model to represent the moisture desorption characteristics of whole limes

Three commonly cited models for drying of agricultural products i.e. Page, Approximate form of diffusion, and Exponential were compared for their ability to the fit the experimental drying data of whole limes based on the root mean square error of estimate (RMSE) of the measured and simulated moisture contents. The comparison shows the Page model is the most suitable model having average RMSE = 0.046 wet-basis (decimal) while the Approximate form of diffusion and the Exponential models have 0.132  and 0.128 wet-basis (decimal),  respectively. This indicated that the Approximate form of diffusion and the Exponential models both have less fitting ability then the  Page model for the entire period (> 7 days) of drying in 30 tests at different combinations of temperatures (35 - 800C) and relative humidities (12.5 – 33.5%). The Page model was found to be most suitable equation, to describe the drying  characteristics of whole mature limes over a typically seven day drying. The Page  models can be used for the simulation of bulk volume of whole limes occurring during ventilated storage as commonly used in the middle east region

Comparison of five commonly used thin-layer moisture transfer models in fitting the re-wetting data of barley

Five commonly cited thin-layer rewetting models, including Page, Diffusion, Approximate form of diffusion, Exponential, and Polynomial were compared for their abilities to the fit the experimental re-wetting data of barley based on the root mean square error (RMSE) and mean relative error (MRE) of estimate of the measured and simulated moisture contents.  The comparison shows the Page model is the most suitable model (average, RMSE = 0.176% d.b. and MRE = 0.713% d.b.) followed by the Diffusion model (average RMSE = 0.199% d.b. and MRE = 0.862% d.b) to fit the re-wetting experimental data of barley.  The Approximate form of diffusion, the Exponential and the Polynomial models have less fitting ability then the Page and Diffusion models for the entire period (> 4 days) of re-wetting of 33 tests at different combinations of temperatures (5.7- 46.30C) and relative humidity (48.2%-88.6%).  The Page and Diffusion models were found to be the most suitable equations, to describe the thin-layer re-wetting characteristics of barley over a typically five day re-wetting.  These two models can be used for the simulation of deep-bed re-wetting of barley occurring during ventilated storage.   Keywords: Thin-layer, barley, re-wetting parameters, temperature, relative humidit

Calorific Value of Dried Branches of Coconut Plant at Different Moisture Contents

The reserves of non-renewable energy sources such as coal, crude oil and natural gas are not limitless, they gradually get exhausted and their price continually increases. This project showed how coconut branches could be an alternative source of energy. The calorific values of dried coconut branches were determined by using the bomb calorimeter along with the data of moisture content. The calorific values were noticed to be indirectly proportional to the moisture content. The calorific values (kJ/kg) of the sample as a function of the moisture content is correlated with correlation coefficient (R2) was 0.96. Ten out of fifteen specimens collected were shown to have moisture content in the range of 10% to 30%. With this moisture content, the amount of calorific values acquired were shown to be in the range of 14-16 MJ/kg which is enough to show its importance and practicality as a source of renewable energy.

The Pt isotopes: comparing the Interacting Boson Model with Configuration Mixing and the Extended Consistent-Q formalism

The role of intruder configurations in the description of energy spectra and B(E2) values in the Pt region is analyzed. In particular, we study the differences between Interacting Boson Model calculations with or without the inclusion of intruder states in the even Pt nuclei $^{172-194}$Pt. As a result, it shows that for the description of a subset of the existing experimental data, i.e., energy spectra and absolute B(E2) values up to an excitation energy of about 1.5 MeV, both approaches seem to be equally valid. We explain these similarities between both model spaces through an appropriate mapping. We point out the need for a more extensive comparison, encompassing a data set as broad (and complete) as possible to confront with both theoretical approaches in order to test the detailed structure of the nuclear wave functions.Comment: To be published in NP

Addendum for the article Radio Graceful Labelling of Graphs

Additional references listed for the article: Saha, Laxman and Basunia, Alamgir Rahaman (2020) Radio Graceful Labelling of Graphs, Theory and Applications of Graphs: Vol. 7: Iss. 1, Article 7. DOI: 10.20429/tag.2020.07010