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Author n_TOF Collaboration (Lerendegui-Marco, J. et al.); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Radiative neutron capture on Pu-242 in the resonance region at the CERN n_TOF-EAR1 facility Type Journal Article
  Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 97 Issue 2 Pages 024605 - 21pp  
  Keywords  
  Abstract The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of Pu-242 there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, postirradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on Pu-242 carried out at nTOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The Pu-242(n, gamma) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of nTOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.  
  Address [Lerendegui-Marco, J.; Guerrero, C.; Quesada, J. M.; Cortes-Giraldo, M. A.; Praena, J.; Sabate-Gilarte, M.] Univ Seville, Dept Fis Atom Mol & Nucl, E-41012 Seville, Spain, Email: cguerrero4@us.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000424190700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3474  
Permanent link to this record
 

 
Author n_TOF Collaboration (Wright, T. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Measurement of the U-238(n,gamma) cross section up to 80 keV with the Total Absorption Calorimeter at the CERN n_TOF facility Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 96 Issue 6 Pages 064601 - 11pp  
  Keywords  
  Abstract The radiative capture cross section of a highly pure (99.999%), 6.125(2) grams and 9.56(5) x 10(-4) atoms/barn areal density U-238 sample has been measured with the Total Absorption Calorimeter (TAC) in the 185 m flight path at the CERN neutron time-of-flight facility n_TOF. This measurement is in response to the NEA High Priority Request list, which demands an accuracy in this cross section of less than 3% below 25 keV. These data have undergone careful background subtraction, with special care being given to the background originating from neutrons scattered by the 238U sample. Pileup and dead-time effects have been corrected for. The measured cross section covers an energy range between 0.2 eV and 80 keV, with an accuracy that varies with neutron energy, being better than 4% below 25 keV and reaching at most 6% at higher energies.  
  Address [Wright, T.; Billowes, J.; Ryan, J. A.; Ware, T.] Univ Manchester, Manchester, Lancs, England, Email: tobias.wright@manchester.ac.uk  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000416848700005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3392  
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Author Wu, J. et al; Algora, A.; Agramunt, J.; Morales, A.I.; Orrigo, S.E.A.; Tain, J.L.; Tarifeño-Saldivia, A.; Tolosa-Delgado, A. doi  openurl
  Title First observation of isomeric states in 111Zr, 113Nb, and 115Mo Type Journal Article
  Year 2022 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 106 Issue 6 Pages 064328 - 5pp  
  Keywords  
  Abstract Isomeric states in the neutron-rich nuclei 111Zr [T1/2 = 0.10(7) μs], 113Nb [T1/2 = 0.7(4) μs], 115Mo [T1/2 = 46(3) μs] were first identified at the Radioactive Ion Beam Factory (RIBF) of RIKEN by using in-flight fission and fragmentation of a 238U beam at an energy of 345 MeV/u. This is a brief report of the gamma transitions de -exciting from isomeric states and half-lives measurements, which provides the first spectroscopy in the nuclear region of prolate-to-oblate shape-phase transition around mass A approximate to 110.  
  Address [Wu, J.] Brookhaven Natl Lab, Natl Nucl Data Ctr, Upton, NY 11973 USA, Email: jwu2@bnl.gov  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000906391600002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5452  
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Author n_TOF Collaboration (Tagliente, G. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Zr-92(n, gamma) and (n,tot) measurements at the GELINA and n_TOF facilities Type Journal Article
  Year 2022 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 105 Issue 2 Pages 025805 - 14pp  
  Keywords  
  Abstract Background: Stellar nucleosynthesis of elements heavier than iron is driven by neutron capture processes. Zr-92 is positioned at a strategic point along the slow nucleosynthesis path, given its proximity to the neutron magic number N = 50 and its position at the matching region between the weak and main slow processes. Purpose: In parallel with recent improved astronomical data, the extraction of accurate Maxwellian averaged cross sections (MACSs) derived from a more complete and accurate set of resonance parameters should allow for a better understanding of the stellar conditions at which nucleosynthesis takes place. Methods: Transmission and capture cross section measurements using enriched Zr-92 metallic samples were performed at the time-of flight facilities GELINA of JRC-Geel (BE) and nTOF of CERN (CH). The neutron beam passing through the samples was investigated in transmission measurements at GELINA using a Li-glass scintillator. The gamma rays emitted during the neutron capture reactions were detected by C6D6 detectors at both GELINA and nTOF. Results: Resonance parameters of individual resonances up to 81 keV were extracted from a combined resonance shape analysis of experimental transmissions and capture yields. For the majority of the resonances the parity was determined from an analysis of the transmission data obtained with different sample thicknesses. Average resonance parameters were calculated. Conclusions: Maxwellian averaged cross sections were extracted from resonances observed up to 81 keV. The MACS for kT = 30 keV is fully consistent with experimental data reported in the literature. The MACSs for kT less than or similar to 15 keV are in good agreement with those derived from the ENDF/B-VIII.0 library and recommended in the KADoNTS database. For kT higher than 30 keV differences are observed. A comparison with MACSs obtained with the cross sections recommended in the JEFF-3.3 and JENDL-4.0 libraries shows discrepancies even for kT less than or similar to 15 keV.  
  Address [Tagliente, G.; Barbagallo, M.; Colonna, N.; Mastromarco, M.; Variale, V.] Ist Nazl Fis Nucl, Sez Bari, Bari, Italy, Email: giuseppe.tagliente@ba.infn.it  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000766732800002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5163  
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Author n_TOF Collaboration (Gawlik, A. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Measurement of the Ge-76(n, gamma) cross section at the n_TOF facility at CERN Type Journal Article
  Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 104 Issue 4 Pages 044610 - 7pp  
  Keywords  
  Abstract The Ge-76(n, gamma) reaction has been measured at the n_TOF facility at CERN via the time-of-flight technique. Neutron capture cross sections on Ge-76 are of interest to a variety of low-background experiments, such as neutrinoless double beta decay searches, and to nuclear astrophysics. We have determined resonance capture kernels up to 52 keV neutron energy and used the new data to calculate Maxwellian-averaged neutron capture cross sections for k(B)T values of 5 to 100 keV.  
  Address [Gawlik-Ramiega, A.; Andrzejewski, J.; Perkowski, J.] Univ Lodz, Lodz, Poland, Email: aleksandra.gawlik@uni.lodz.pl  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000707420400002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5003  
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Author n_TOF Collaboration (Balibrea-Correa, J. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Measurement of the alpha ratio and (n, gamma) cross section of U-235 from 0.2 to 200 eV at n_TOF Type Journal Article
  Year 2020 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 102 Issue 4 Pages 044615 - 18pp  
  Keywords  
  Abstract We measured the neutron capture-to-fission cross-section ratio (alpha ratio) and the capture cross section of U-235 between 0.2 and 200 eV at the nTOF facility at CERN. The simultaneous measurement of neutron-induced capture and fission rates was performed by means of the nTOF BaF2 Total Absorption Calorimeter (TAC), used for detection of gamma rays, in combination with a set of micromegas detectors used as fission tagging detectors. The energy dependence of the capture cross section was obtained with help of the Li-6(n, t) standard reaction determining the n_TOF neutron fluence; the well-known integral of the U-235(n, f) cross section between 7.8 and 11 eV was then used for its absolute normalization. The alpha ratio, obtained with slightly higher statistical fluctuations, was determined directly, without need for any reference cross section. To perform the analysis of this measurement we developed a new methodology to correct the experimentally observed effect that the probabilities of detecting a fission reaction in the TAC and the micromegas detectors are not independent. The results of this work have been used in a new evaluation of U-235 performed within the scope of the Collaborative International Evaluated Library Organisation (CIELO) Project, and are consistent with the ENDF/B-VIII.0 and JEFF-3.3 capture cross sections below 4 eV and above 100 eV. However, the measured capture cross section is on average 10% larger between 4 and 100 eV.  
  Address [Balibrea-Correa, J.; Mendoza, E.; Cano-Ott, D.] Ctr Invest Energet Medioambientales & Tecnol, CIEMAT, Madrid, Spain, Email: emilio.mendoza@ciemat.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000579839000003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4575  
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Author n_TOF Collaboration (Stamatopoulos, A. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Investigation of the Pu-240(n, f) reaction at the n_TOF/EAR2 facility in the 9 meV-6 MeV range Type Journal Article
  Year 2020 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 102 Issue 1 Pages 014616 - 23pp  
  Keywords  
  Abstract Background: Nuclear waste management is considered amongst the major challenges in the field of nuclear energy. A possible means of addressing this issue is waste transmutation in advanced nuclear systems, whose operation requires a fast neutron spectrum. In this regard, the accurate knowledge of neutron-induced reaction cross sections of several (minor) actinide isotopes is essential for design optimization and improvement of safety margins of such systems. One such case is Pu-240, due to its accumulation in spent nuclear fuel of thermal reactors and its usage in fast reactor fuel. The measurement of the Pu-240(n, f) cross section was previously attempted at the CERN nTOF facility EAR1 measuring station using the time-of-flight technique. Due to the low amount of available material and the given flux at EAR1, the measurement had to last several months to achieve a sufficient statistical accuracy. This long duration led to detector deterioration due to the prolonged exposure to the high alpha activity of the fission foils, therefore the measurement could not be successfully completed. Purpose: It is aimed to determine whether it is feasible to study neutron-induced fission at nTOF/EAR2 and provide data on the Pu-240(n, f) reaction in energy regions requested for applications. Methods: The study of the Pu-240(n, f) reaction was made at a new experimental area (EAR2) with a shorter flight path which delivered on average 30 times higher flux at fast neutron energies. This enabled the measurement to be performed much faster, thus limiting the exposure of the detectors to the intrinsic activity of the fission foils. The experimental setup was based on microbulk Micromegas detectors and the time-of-flight data were analyzed with an optimized pulse-shape analysis algorithm. Special attention was dedicated to the estimation of the non-negligible counting loss corrections with the development of a new methodology, and other corrections were estimated via Monte Carlo simulations of the experimental setup. Results: This new measurement of the Pu-240(n, f) cross section yielded data from 9 meV up to 6 MeV incident neutron energy and fission resonance kernels were extracted up to 10 keV. Conclusions: Neutron-induced fission of high activity samples can be successfully studied at the n_TOF/EAR2 facility at CERN covering a wide range of neutron energies, from thermal to a few MeV.  
  Address [Stamatopoulos, A.; Tsinganis, A.; Kokkoris, M.; Vlastou, R.; Diakaki, M.] Natl Tech Univ Athens, Athens, Greece, Email: athanasios.stamatopoulos@cern.ch  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000551057500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4466  
Permanent link to this record
 

 
Author Phong, V.H. et al; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Morales, A.I.; Tain, J.L.; Tarifeño-Saldivia, A.; Tolosa-Delgado, A. doi  openurl
  Title Observation of a μs isomer in In-134(49)85: Proton-neutron coupling “southeast” of Sn-132(50)82 Type Journal Article
  Year 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 100 Issue 1 Pages 011302 - 6pp  
  Keywords  
  Abstract We report on the observation of a microsecond isomeric state in the single-proton-hole, three-neutron-particle nucleus In-134. The nuclei of interest were produced by in-flight fission of a U-238 beam at the Radioactive Isotope Beam Factory at RIKEN. The isomer depopulates through a gamma ray of energy 56.7(1) keV and with a half-life of T-1/2 = 3.5(4) μs. Based on the comparison with shell-model calculations, we interpret the isomer as the I-pi = 5(-) member of the pi 0g(9/2)(-1) circle times nu 1f(7/2)(3) multiplet, decaying to the I-pi = 7(-) ground state with a reduced-transition probability of B(E2; 5(-) -> 7(-)) = 0.53(6) W.u. Observation of this isomer, and lack of evidence in the current work for a I-pi = 5(-) isomer decay in In-132, provides a benchmark of the proton-neutron interaction in the region of the nuclear chart “southeast” of Sn-132, where experimental information on excited states is sparse.  
  Address [Phong, V. H.; Lorusso, G.; Liu, J.; Matsui, K.; Nishimura, S.; Ahn, D. S.; Baba, H.; Go, S.; Isobe, T.; Kiss, G.; Kubono, S.; Sakurai, H.; Shimizu, Y.; Sumikama, T.; Suzuki, H.; Takeda, H.] RIKEN, RIKEN Nishina Ctr, 2-1 Hirosawa, Wako, Saitama 3510198, Japan, Email: giuseppe.lorusso@npl.co.uk  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000477895400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4080  
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Author Tarifeño-Saldivia, A.; Soto, L. doi  openurl
  Title Effects of gas chamber geometry and gas flow on the neutron production in a fast plasma focus neutron source Type Journal Article
  Year 2014 Publication Plasma Physics and Controlled Fusion Abbreviated Journal Plasma Phys. Control. Fusion  
  Volume 56 Issue 12 Pages 125013 - 5pp  
  Keywords pulsed neutron source; repetitive plasma focus; neutron yield measurement; fast plasma focus  
  Abstract This work reports that gas chamber geometry and gas flow management substantially affect the neutron production of a repetitive fast plasma focus. The gas flow rate is the most sensitive parameter. An appropriate design of the gas chamber combined with a suitable flow-rate management can lead to improvements in the neutron production of one order of magnitude working in a fast repetitive mode.  
  Address [Tarifeno-Saldivia, Ariel; Soto, Leopoldo] Comis Chilena Energia Nucl CCHEN, Santiago, Chile, Email: atarisal@gmail.com;  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0741-3335 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000346926300024 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2070  
Permanent link to this record
 

 
Author Pavez, C.; Pedreros, J.; Tarifeño-Saldivia, A.; Soto, L. doi  openurl
  Title Observation of plasma jets in a table top plasma focus discharge Type Journal Article
  Year 2015 Publication Physics of Plasmas Abbreviated Journal Phys. Plasmas  
  Volume 22 Issue 4 Pages 040705 - 5pp  
  Keywords  
  Abstract In the last years, medium size Z-pinch experiments operating at tens of kJ are being used to create supersonic plasma jets. Those experiments are produced with wire arrays and radial foils, and they are conducted in generators based on water-filled transmission lines. Also plasma jets have been observed in small X-pinch experiments operating at 1 kJ. In this work, observations of plasma jets produced in a table top plasma focus device by means of optical and digital interferometry are shown. The device was operated at only similar to 70J, achieving 50 kA in 150 ns. The plasma jets were observed after the pinch, in the region close and on the anode, along the axis. The electron density measured from the jets is in the range 10(24)-10(25) m(-3). From two consecutive plasma images separated 18 ns, the axial jet velocity was measured in the order of 4 x 10(4) m/s.  
  Address [Pavez, Cristian; Pedreros, Jose; Tarifeno-Saldivia, Ariel; Soto, Leopoldo] CCHEN, Comis Chilena Energia Nucl, Santiago, Chile, Email: lsoto@cchen.cl  
  Corporate Author Thesis  
  Publisher Amer Inst Physics Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1070-664x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000353837200006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2400  
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