Superfluid signatures in a dissipative quantum point contact

Huang, M.-Z.*; Mohan, J.*; Visuri, A.-M.*; Fabritius, P.*; Talebi, M.*; Wili, S.*; Uchino, Shun; Giamarchi, T.*; Esslinger, T.*

Physical Review Letters, 130(20), p.200404_1 - 200404_8, 2023/05

https://doi.org/10.1103/PhysRevLett.130.200404

We measure superfluid transport of strongly-interacting fermionic lithium atoms through a quantum point contact with local, spin-dependent particle loss. We observe that the characteristic non-Ohmic superfluid transport enabled by high-order multiple Andreev reflections transitions into an excess Ohmic current as the dissipation strength exceeds the superfluid gap. We develop a model with mean-field reservoirs connected via tunneling to a dissipative site. Our calculations in the Keldysh formalism reproduce the observed non-equilibrium particle current, yet do not fully explain the observed loss rate or spin current.

Effect of particle size on the colonization of biofilms and the potential of biofilm-covered microplastics as metal carriers

Wu, C.*; Tanaka, Kazuya; Tani, Yukinori*; Bi, X.*; Liu, J.*; Yu, Q.*

Science of the Total Environment, 821, p.153265_1 - 153265_9, 2022/05

https://doi.org/10.1016/j.scitotenv.2022.153265

Microplastics (MPs) with different particle sizes were co-cultured with a model freshwater fungus, strain KR21-2, to form biofilms on their surface. We also determined the changes in surface physicochemical properties of the biofilm-covered MPs (BMPs) and the heavy metal adsorption capacity of the original MPs and BMPs. The results revealed that the biofilms improve the adsorption of heavy metals on MPs, and the particle size of MPs plays a crucial role in biofilm colonization and adsorption of heavy metals by BMPs.

Integration of pool scrubbing research to enhance source-term calculations (IPRESCA) project

Gupta, S.*; Herranz, L. E.*; Lebel, L. S.*; Sonnenkalb, M.*; Pellegrini, M.*; Marchetto, C.*; Maruyama, Yu; Dehbi, A.*; Suckow, D.*; Krkel, T.*

Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 16 Pages, 2022/03

The Joint evaluated fission and fusion nuclear data library, JEFF-3.3

Plompen, A. J. M.*; Cabellos, O.*; De Saint Jean, C.*; Fleming, M.*; Algora, A.*; Angelone, M.*; Archier, P.*; Bauge, E.*; Bersillon, O.*; Blokhin, A.*; et al.

European Physical Journal A, 56(7), p.181_1 - 181_108, 2020/07

https://doi.org/10.1140/epja/s10050-020-00141-9

The Joint Evaluated Fission and Fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides U, U and Pu, on Am and Na, Ni, Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yileds, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 is excellent for a wide range of nuclear technology applications, in particular nuclear energy.

ETSON-MITHYGENE benchmark on simulations of upward flame propagation experiment in the ENACCEF2 experimental facility

Bentaib, A.*; Chaumeix, N.*; Grosseuvres, R.*; Bleyer, A.*; Gastaldo, L.*; Maas, L.*; Jallais, S.*; Vyazmina, E.*; Kudriakov, S.*; Studer, E.*; et al.

Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 11 Pages, 2018/10

Unravelling the role of steps in CuO formation via hyperthermal O adsorption at Cu(410)

Okada, Michio*; Vattuone, L.*; Gerbi, A.*; Savio, L.*; Rocca, M.*; Moritani, Kosuke*; Teraoka, Yuden; Kasai, Toshio*

Journal of Physical Chemistry C, 111(46), p.17340 - 17345, 2007/11

https://doi.org/10.1021/jp074520t

We report a study on the oxidation process of Cu(410) using high-resolution electron energy loss spectroscopy and X-ray photoemission spectroscopy using synchrotron radiation. We demonstrate that a hyperthermal O molecular beam (HOMB) is an efficient tool to fabricate CuO thin film also at room temperature. The efficiency of the CuO formation in the initial stages depends on the angle of incidence of HOMB. Step roughening, acting as a source of mobile precursor Cu adatoms and opening channels for bulk diffusion of the O atoms, is a key feature in determining the CuO formation rate.

Role of steps in CuO formation on Cu(410) using a hyperthermal O molecular beam

Okada, Michio*; Vattuone, L.*; Moritani, Kosuke*; Gerbi, A.*; Savio, L.*; Yoshigoe, Akitaka; Teraoka, Yuden; Rocca, M.*; Kasai, Toshio*

no journal, , 

It is important to make clear oxidation processes of Cu from an industrial view point because cupper oxides are candidates of high-Tc super conductor and solar cells. However, the details of the chemical reaction dynamics for the Cu oxidation processes have not been understood yet. We have already studied initial oxidation processes of Cu(100) and Cu(110) surfaces by using supersonic oxygen molecular beams. In this research, effects of surface defects for the surface oxidation are investigated by using the Cu(410) surface with large step density. It was found that oxidation rate of the Cu(410) surface was larger than Cu(100) surface, but, smaller than Cu(110) surface in the oxygen coverage range larger than 0.5 monolayer, from which formation of CuO was observed. The phenomenon can be understood from the fact that the (410) surface consists of (100) terraces and (110) steps.

Extension of fission reaction model FIFRELIN for wider reaction conditions and post processing

Ogawa, Tatsuhiko; Litaize, O.*; Mancusi, D.*; Chebboubi, A.*; Serot, O.*

no journal, , 

The Monte-Carlo code FIFRELIN was originally developed for the simulation of first chance fissions of fissile nuclei. In case of neutron-induced fissions, the compound nucleus always fissioned from an exited state whose excitation energy is sum of the incoming neutron energy and the neutron binding energy. While in the new version, with the multi-chance fission algorithm, the fissioning nuclei can start from higher exited states considering the competition of fission reactions, neutron emission, and gamma emission. When fission is selected in the competition, the partitioning of mass, charge, excitation energy, and angular momentum to the two fission fragments is determined either by the FIFRELIN native algorithm or by GEF. In fission reactions induced by energetic neutrons, pre-fission particle emission reduces the excitation energy of the compound nucleus before fission, leading to a noticeable difference of the final observables such as neutron multiplicity and fission product mass distribution. The other updated feature is the interface to codes handling the post-reaction processes. The energy spectra of neutrons, electrons and photons from fission reactions are output in a format compatible with PHITS, a general-purpose particle transport code. By using this functionality, one can simulate the transport and reactions of particles based on the cross section data and reaction models of PHITS, and the spectra calculated by FIFRELIN. Finally, the other interface developed in this study is nuclide yield output in a format compatible with DCHAIN-SP2014, a burn-up calculation code. This interface is necessary to consider the build-up, which depends on the time structure of the incoming neutron beam as well as the decay during the cooling period.

New results in the modeling of fission and radiative neutron capture with FIFRELIN

Litaize, O.*; Piau, V.*; Chalil, A.*; Ogawa, Tatsuhiko; Chebboubi, A.*; Gook, A.*; Gunsing, F.*; Kessedjian, G.*; Lhuillier, D.*; Mancusi, D.*; et al.

no journal, , 

The Monte-Carlo code FIFRELIN was originally developed for the simulation of first chance fission of fissile nuclei. In this study, its interfaces to radiation transport code PHITS, extension for neutron capture reactions, and a function to calculate neutrinos from fission fragments were developed. In order to extend FIFRELIN for neutron capture reactions, accurate gamma-ray yield was obtained by tuning the level density considering the nuclide species and excitation energy. Accurate neutrino yield was obtained by adopting up-to-date database on the thermal neutron capture state. JAEA developed an interface of FIFRELIN to PHITS to perform new FIFRELIN benchmark using FIFRELIN-DCHAIN joint calculation.

Investigation of the structure of U(n,fission) prompt gamma energy spectrum by FIFRELIN

Ogawa, Tatsuhiko; Litaize, O.*; Mancusi, D.*; Chebboubi, A.*; Serot, O.*

no journal, , 

Thermal fission of U-235 is fundamental for nuclear energy engineering, whose details were observed through neutrons and gamma-rays. Among them, gamma-rays above 8 MeV, which come from immediate gamma deexcitation of fission fragments, were recently measured as a probe to observe fission more directly. The energy spectrum measured by a theoretical model CoH3 (Coupled-Channels Hauser-Feshbach Code) reproduced a peak around 4 MeV and a shoulder from 6 to 8 MeV, however, underestimated the components above 14 MeV. In this study, we used FIFRELIN developed by the French Atomic Energy, Alternative Energy Commission (CEA) to reproduce the gamma-ray energy spectrum. In addition to the peak around 4 MeV and a shoulder from 6 to 8 MeV, gamma spectrum up to 20 MeV was reproduced. This calculation also discovered that the level-density model for fission fragments plays the critical role. It was thus illustrated that FIFRELIN is useful to reproduce the spectra of gamma-ray from fission and investigate the reaction processes responsible for gamma-ray spectrum.