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Ambient neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He3 neutron counters are used for a detailed study of the ambient neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to neutrons of energies higher than 10 MeV. For each He3 counter moderator assembly, the energy-dependent neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the neutron energy spectrum from 10-9 to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61±0.05), (1.96±0.15), and (4.6±0.4)×10-4 cm-2 s-1, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls., Financial support by DFG (BE 4100/4-1), the Helmholtz Association (NAVI VH-VI-417 and ERC-RA-0016), the Spanish Ministerio de Economía y Competitividad (Grants No. FPA2014-52823-C2, No. FPA2017-83946-C2, No. RTI2018-098868-B-I00, and No. SEV-2014-0398/ program Severo Ochoa), and the COST Association (ChETEC CA16117) is gratefully acknowledged

β-delayed one-neutron and two-neutron branching ratios (P1n and P2n) have been measured in the decay of A=84 to 87 Ga isotopes at the Radioactive-Isotope Beam Factory (RIBF) at the RIKEN Nishina Center using a high-efficiency array of He3 neutron counters (BRIKEN). Two-neutron emission was observed in the decay of Ga84,85,87 for the first time and the branching ratios were measured to be P2n=1.6(2)%,1.3(2)%, and 10.2(28)stat(5)sys%, respectively. One-neutron branching ratio of Ga87(P1n=81(9)stat(8)sys%) and half-life of 29(4) ms were measured for the first time. The branching ratios of Ga86 were also measured to be P1n=74(2)stat(8)sys% and 16.2(9)stat(6)sys% with better precision than a previous study. The observation that P1n>P2n for both Ga86,87 was unexpected and is interpreted as a signature of dominating one-neutron emission from the two-neutron unbound excited states in Ge86,87. In order to interpret the experimental results, shell-model and Hauser-Feshbach statistical model calculations of delayed particle and γ-ray emission probabilities were performed. This model framework reproduces the experimental results. The shell model alone predicts P2n significantly larger than P1n for the Ga87 decay, and it is necessary to invoke a statistical description to successfully explain the observation that P1n>P2n. Our new results demonstrate the relevance and importance of a statistical description of neutron emission for the prediction of the decay properties of multineutron emitters and that it must be included in the r-process modeling.

6 pags., 3 figs., Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions of Nb100gs,100m and Nb102gs,102m β decays have been determined using the total absorption γ-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyväskylä. Here, the double Penning trap system JYFLTRAP was employed to disentangle the β decay of the isomeric states. The new data obtained in this challenging measurement have a large impact in antineutrino summation calculations. For the first time the discrepancy between the summation model and the reactor antineutrino measurements in the region of the shape distortion has been reduced., This work has been supported by the Spanish Ministerio de Economía y Competitividad under Grants No. FPA2011- 24553, No. AIC-A-2011-0696, No. FPA2014-52823-C2-1- P, No. FPA2015-65035-P, No. FPI/BES-2014-068222, and the program Severo Ochoa (SEV-2014-0398), by the Spanish Ministerio de Educación under the FPU12/01527 Grant, by the European Commission under the FP7/EURATOM Contract No. 605203 and the FP7/ENSAR Contract No. 262010, and by the Junta para la Ampliación de Estudios Programme (CSIC JAE-Doc contract) co-financed by ESF. V. G. thanks the support of K. Zygmunt. This work was supported by the Academy of Finland under the Finnish Centre of Excellence Programme (Project No. 213503, Nuclear and Accelerator-Based Physics Research at JYFL). It was also supported by the UK Science and Technology Facilities Council (STFC) Grant No. ST/ F012012/1.

The present invention relates to a system (10) and method for the volumetric and isotopic identification of the spatial distribution of ionising radiation from point or extensive radioactive sources (3) in radioactive surroundings. More specifically, this system (10) comprises a gamma radiation detector (2) and an optical transducer (1) joined to each other and linked to a control unit to detect the absolute position of radioactive sources (3) relative to a visual reference located in the radioactive surroundings, and to determine the radioactive activity of the sources, that is to say it detects the isotope composition of the radioactive sources (3). [EN], La presente invención es un sistema (10) y método para la identificación volumétrica e isotópica de la distribución espacial de una radiación ionizante procedente de fuentes radioactivas (3) puntuales, o extensas, en escenas radioactivas. Más concretamente, este sistema (10) comprende: un detector de radiación gamma (2) y un transductor óptico (1) solidarios entre si y vinculados con una unidad de control para detectar la posición absoluta, con respecto a una referencia visual que se encuentra en la escena radioactiva, de las fuentes radioactivas (3) y determina su actividad radioactiva, es decir detecta la composición de isótopos de las fuentes radioactivas (3). [ES], Consejo Superior de Investigaciones Científicas (España), Universitat de València, Empresa Nacional de Residuos Radiactivos S.A. (ENRESA), A1 Solicitud de patente con informe sobre el estado de la técnica

S. Rice et al. -- 10 pags., 12 figs., 4 tabs., The beta decays of Br86 and Rb91 have been studied using the total absorption spectroscopy technique. The radioactive nuclei were produced at the Ion Guide Isotope Separator On-Line facility in Jyväskylä and further purified using the JYFLTRAP. Br86 and Rb91 are considered to be major contributors to the decay heat in reactors. In addition, Rb91 was used as a normalization point in direct measurements of mean gamma energies released in the beta decay of fission products by Rudstam et al. assuming that this decay was well known from high-resolution measurements. Our results show that both decays were suffering from the Pandemonium effect and that the results of Rudstam et al. should be renormalized. The relative impact of the studied decays in the prediction of the decay heat and antineutrino spectrum from reactors has been evaluated., This work was supported by Spanish Ministerio de Economía y Competitividad under grants FPA2008-06419, FPA2010-17142, FPA2011-24553, FPA2014-52823-C2-1- P, FIS2014-51971-P, and CPAN CSD-2007-00042 (Ingenio2010), and the program Severo Ochoa (SEV-2014-0398), by EPSRC and STFC (UK), and by the CHANDA European project, the In2p3 institute of the CNRS, and the NEEDS challenge through the NACRE project. Work at ANL was supported by the U.S. Department of Energy under contract DE-AC02-06CH11357.

Sistema y método para la identificación volumétrica e isotópica de distribuciones de escenas radioactivas. La presente invención es un sistema (10) y método para la identificación volumétrica e isotópica de la distribución espacial de una radiación ionizante procedente de fuentes radioactivas (3) puntuales, o extensas, en escenas radioactivas. Más concretamente, este sistema (10) comprende: un detector de radiación gamma (2) y un transductor óptico (1) solidarios entre si y vinculados con una unidad de control para detectar la posición absoluta, con respecto a una referencia visual que se encuentra en la escena radioactiva, de las fuentes radioactivas (3) y determina su actividad radioactiva, es decir detecta la composición de isótopos de las fuentes radioactivas (3)., Consejo Superior de Investigaciones Científicas (España), Universitat de València, Empresa Nacional de Residuos Radioactivos (ENRESA), A1 Solicitud de patente con informe sobre el estado de la técnica

V. Guadilla et al. -- 10 pags., 10 figs., 2 tabs., The β decay of Tc100 has been studied by using the total absorption γ-ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. In this work the new Decay Total Absorption γ-ray Spectrometer in coincidence with a cylindrical plastic β detector has been employed. The β intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximation framework are also reported. Comparison of these calculations with our measurement serves as a benchmark for calculations of the double β decay of Mo100., This work has been supported by the Spanish Ministerio de Economía y Competitividad under Grants No. FPA2011-24553, No. AIC-A-2011-0696, No. FPA2014-52823-C2-1-P, No. FPA2015-65035-P, and No. FPI/BES-2014-068222, and by the program Severo Ochoa (SEV-2014-0398), by the Spanish Ministerio de Educación, Cultura y Deporte under the FPU12/01527 Grant, by the European Commission under the FP7/EURATOM contract 605203 and the FP7/ENSAR contract 262010, and by the Junta para la Ampliación de Estudios Programme (CSIC JAE-Doc contract) co-financed by FSE. This work has been partially supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2012-2017 (Project No. 213503, Nuclear and Accelerator Based Programme at JYFL). W.G. was supported by the UK Science and Technology Facilities Council (STFC) Grant ST/F012012/1 and by the Atracció de talent VLC-CAMPUS Programme of the University of Valencia.

Pragati et al. ; 8 págs.; 9 figs.; 2 tabs. ; Open Access funded by Creative Commons Atribution Licence 3.0, γ rays following the EC/β+ and α decay of the N = 126, Fr213 nucleus have been observed at the CERN isotope separator on-line (ISOLDE) facility with the help of γ-ray and conversion-electron spectroscopy. These γ rays establish several hitherto unknown excited states in Rn213. Also, five new α-decay branches from the Fr213 ground state have been discovered. Shell model calculations have been performed to understand the newly observed states in Rn213. Published by the American Physical Society, Financial support from the European Union Sixth Framework through RII3-EURONS Contract No. 506065, the UK STFC, the Spanish MINECO through Grants No. FPA2005-03993, No. FPA2013-41267-P, No. FPA2014-52823-C2-1-P, and No. FPA2015-65035-P, and the Centro de Excelencia Severo Ochoa del IFIC SEV-2014-0398 Projects is gratefully acknowledged. Pragati acknowledges financial support from the Ministry of Human Resource Development, Government of India.

13 págs.; 11 figs. ; 1 tab., The rare-earth region of the nuclear table around the quasi-doubly magic nucleus Gd146 is one of the very few places in which the Gamow-Teller (GT) resonance can be populated in β decay. The appropriate technique to study such a phenomenon is total absorption spectroscopy, thanks to which one can measure the B(GT) distribution in β-decay experiments even when it is very fragmented and lies at high excitation energy in the daughter nucleus. Results on the GT resonance measured in the β decay of the odd-Z, N=83 nuclei Tb148, Ho150, and Tm152 are presented in this work and compared with shell-model calculations. The tail of the resonance is clearly observed up to the limit imposed by the Q value. This observation is important in the context of the understanding of the >quenching> of the GT strength. ©2016 American Physical Society, The authors would like to thank the GSI accelerator crew and the MSEP group for their support. This work has been partially supported by the Spanish Ministry (Grants No. FPA2005-03993, No. FPA200806419-C02-01, No. FPA2011- 24553, No. FPA2012-32443, No. FPA2014-57196-C5, and No. FPA2014-52823-C2-1-P) and the Generalitat Valenciana (PROMETEOII/2014/019).

[ES] Cámara Compton focalizable equipada con detectores de separación variable. La presente invención se refiere a una cámara Compton focalizable que comprende: un detector de dispersión Compton (1); uno o más detectores de absorción (2, 2'), cuyos planos se encuentran separados del plano del detector de dispersión (1); y un sistema mecánico (3) de separación de los detectores de dispersión (1) y de absorción (2, 2') para variar la citada distancia (d) comprendida entre dichos detectores (1, 2, 2'). La invención permite mejorar la información asociada a la formación de imágenes por medio de radiación gamma, mediante el cálculo de la distancia de los objetos evaluados, así como identificar la distribución de los radioisótopos presentes en dichos objetos, superando así las limitaciones de otros equipos y cámaras del estado de la técnica., [EN] The invention relates to a focusable Compton camera comprising: a Compton dispersion detector (1); at least one absorption detector (2, 2'), the planes of which are separate from the plane of the dispersion detector (1); and a mechanical system (3) for separating the dispersion (1) and absorption detectors (2, 2') so as to vary said distance (d) between said detectors (1, 2, 2'). The invention allows the improvement of the information associated with the formation of images by means of gamma radiation, by calculating the distance of the evaluated objects, and identifying the distribution of the radioisotopes present in said objects, thereby overcoming the limitations of other equipment and cameras of prior art., Consejo Superior de Investigaciones Científicas (España), Universitat de València, Empresa Nacional de Residuos Radioactivos, B1 Patente sin examen previo

8 pags.; 5 figs.; 2 tabs.; PACS number(s): 23.40.Hc, 27.80.+w, 29.30.Kv; Open Access funded by Creative Commons Atribution Licence 3.0, The beta decay of Pb-192,Pb-190 has been studied using the total absorption technique at the ISOLDE (CERN) facility. The beta-decay strength deduced from the measurements, combined with QRPA theoretical calculations, allow us to infer that the ground states of the Pb-192,Pb-190 isotopes are spherical. These results represent the first application of the shape determination method using the total absorption technique for heavy nuclei and in a region where there is considerable interest in nuclear shapes and shape effects. Published by the American Physical Society, This work has been supported by the Spanish Ministerio de Ciencia e Innovacion y Ministerio de Economıía y Competitividad through projects no. FPA2008-06419-C02-01, FPA2011-24553, FPA2013-41267-P, FPA2014-52823-C2-1- P, FRPA2012-32443, FIS2011-23565, and CSD-2007-00042 (CPAN Consolider, Ingenio2010), by the European Union Seventh Framework via ENSAR (contract no. 262010), contract no. PIOF-GA-2011-298364 and by OTKA contracts no. K100835 and K106035. Some of the Spanish projects are co-financed by FEDER funds.

A study of the Gamow-Teller strength distributions B(GT) in the beta decay of 78Sr and 76,78Rb has been made using a total absorption spectrometer (TAS). Following the success in deducing the sign of the deformation for 76Sr, a similar approach is adopted for 78Sr based on a comparison of the measured B(GT) with quasiparticle random-phase approximation calculations. This work confirms its previously expected prolate deformation in the ground state. Conclusions about the structure of the odd-odd 76,78Rb isotopes have been drawn based on their measured B(GT) distributions. © 2013 American Physical Society., This work was supported in part by the Spanish MEC under Grant No. FPA2005-03993 and Formación Profesorado Universitario Grant No. FPA2003-4041. It was also supported by MICINN Grants No. FPA2008-06419-C02-01, No. FPA2009-07387, No. FPA2010-17142, No. FPA2011-24533, and No. FIS2011-23565, by CPAN CSD-2007-00042, Ingenio 2010, and by the UK Science and Technology Facilities Council (STFC) Grant No. ST/F012012/1. The experiments were partly supported through EURONS No. 506065.

The gamma rays and conversion electrons emitted in the beta decay of (78)Sr to levels in (78)Rb have been studied using Ge detectors and a mini-orange spectrometer. A reliable level scheme based on the results of these experiments has been established. The properties of the levels in (78)Rb have been compared with calculations based on deformed Hartree-Fock with Skyrme interactions and pairing correlations in the BCS approximation. This has allowed an interpretation of the nature of the observed sets of levels in the odd-odd nucleus (78)Rb., This work was supported in part by the Spanish MEC under Grant No. FPA2005-03993 and a Formacion Profesorado Universitario (FPU) fellowship (FPA2003-4041). It was also supported by MICINN nuclear Grants No. FPA2008-06419- C02-01, No. FPA2009-07387, and No. FPA2010-17142 and by the U.K. Science and Technology Facilities Council (STFC) Grant No. ST/F012012/1. The experiments were partly supported through EURONS No. 506065.

The beta feeding probability of Tc-102,Tc- 104,Tc- 105,Tc- 106,Tc- 107, Mo-105, and Nb-101 nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the gamma component of the decay heat for Pu-239 in the 4-3000 s range., This work was supported by the following projects: Spanish FPA 2005-03993 and FPA2008-06419-C02-01; Hungarian OTKA K72566; the EC Contract No. MERG-CT-2004-506849; the Finnish Center of Excellence Programme 2006-2011, the EU 6th Framework Programme (Contract No. 506065 (EURONS), and the Hungarian-Spanish collaboration program.

Several low-lying excited states in 86205Rn119 and 84201Po117 were identified for the first time following EC/β+ decay of Fr205 and At201, respectively, using γ-ray and conversion electron spectroscopy at the CERN isotope separator on-line (ISOLDE) facility. The EC/β+ branch from Fr205 was measured to be 1.5(2)%. The excited states of the daughter nuclei are understood in terms of the odd nucleon coupling to the neighboring even-even core. The neutron single-particle energies of the p3/2 orbital relative to the f5/2 ground state in Rn205, and the f5/2 orbital relative to the p3/2 ground state in Po201, were determined to be 31.4(2) and 5.7(3) keV, respectively. We tentatively identify a 132+ isomeric level at 657.1(5) keV in Rn205. The systematic behavior of the 132+ and 32- levels is also discussed. © 2010 The American Physical Society., Financial support from the UK STFC and AWE plc, the Spanish MEC FPA2007-07393, CSPD-2007-00042 CPAN, FPA2005-03993, and FPA 2008-06419-C02-01 projects. Partial support from the Ramon y Cajal program.