nuclear core
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2021 ◽  
Vol 3 (6) ◽  
pp. 76-83
Author(s):  
E. A. Thompson ◽  
I. O. Akpan ◽  
C. A. Thompson

In this study, we solve the non-relativistic radial part of the Schrödinger wave equation for the superposition of the Hulthen with spin-orbit plus adjusted Coulomb potential (SHSC) potential using the Nikiforov-Uvarov (NU) method for arbitrary states. The Hulthen with spin-orbit plus adjusted Coulomb (SHSC) potential is the simplest potential field for a nuclear system and has been used to obtain the single particle energy spectrum for both nucleon species orbiting a closed nuclear core. We also obtained in this study the corresponding single particle normalized wave function expressed in terms of the Jacobi polynomial. Besides, we obtained two special cases of the energy spectra for the SHSC potential.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Coraline Stasser ◽  
Guy Terwagne ◽  
Jacob Lamblin ◽  
Olivier Méplan ◽  
Guillaume Pignol ◽  
...  

AbstractMURMUR is a new passing-through-walls neutron experiment designed to constrain neutron-hidden neutron transitions allowed in the context of braneworld scenarios or mirror matter models. A nuclear reactor can act as a source of hidden neutrons, such that neutrons travel through a hidden world or sector. Hidden neutrons can propagate out of the nuclear core and far beyond the biological shielding. However, hidden neutrons can weakly interact with usual matter, making possible for their detection in the context of low-noise measurements. In the present work, the novelty rests on a better background discrimination and the use of a mass of a material – here lead – able to enhance regeneration of hidden neutrons into visible ones to improve detection. The input of this new setup is studied using both modelizations and experiments, thanks to tests currently performed with the experiment at the BR2 research nuclear reactor (SCK$$\cdot $$ · CEN, Mol, Belgium). A new limit on the neutron swapping probability p has been derived thanks to the measurements taken during the BR2 Cycle 02/2019A: $$p<4.0\times 10^{-10} \; \text {at 95}\%\text { CL}$$ p < 4.0 × 10 - 10 at 95 % CL . This constraint is better than the bound from the previous passing-through-wall neutron experiment made at ILL in 2015, despite BR2 is less efficient to generate hidden neutrons by a factor of 7.4, thus raising the interest of such experiment using regenerating materials.


2021 ◽  
Vol 252 ◽  
pp. 04003
Author(s):  
Ismael Martel

Halo nuclei are extreme nuclear states consisting of one or more weakly-bound valence nucleons spatially decoupled from a tightly bound nuclear core. The weakly bound nature of the halo dominates the reaction probability, but the specific reaction mechanisms depend also on the core and target nuclei. Despite of the inherent complexity of the reaction process, simple two-body models and direct reaction theories can be used to extract useful information of the structure of the halo nucleus and its dynamics. These ideas are discussed using selected experiments of Coulomb barrier reactions with one- and two- neutron halo systems.


2021 ◽  
Vol 247 ◽  
pp. 02018
Author(s):  
Paul Turinsky ◽  
Aaron Graham ◽  
Hisham Sarsour ◽  
Benjamin Collins

Nuclear core simulators based upon few-group nodal diffusion method currently are widely used to predict light water reactor core behavior. Nodal parameters’ input, e.g. cross-sections, discontinuity factors, and pin form factors, are typically generated utilizing lattice physics codes. In doing so, a number of approximations are introduced related to using zero current boundary conditions, 2-D radial geometry, and uniform thermal conditions in coolant and fuel. Usage of full core models with prediction fidelity typical of lattice physics to predict nodal parameters would eliminate these approximations. The VERA code can serve as such a full core model and was so utilized in this work. Via subsequent processing of VERA predictions, for a range of state points, nodal parameters and their functionalization in terms of coolant density, fuel temperature, and soluble poison concentration, were obtained and input to the NESTLE nodal code. By processing VERA predictions using consistent nodal methodologies as used in NESTLE, when using nodal parameters after functionalization based upon All-Rods-Out (ARO) VERA state points, the maximum reactivity and pin power differences between VERA and NESTLE were 2 pcm and 0.003 for ARO core simulations. For rodded core simulations, these maximum differences grew to 58 pcm and 0.04. Increases in differences were determined to be attributed to usage of unrodded nodal parameters generated using the VERA ARO state points whether the core is partially rodded or not, consistent with lattice physics practice. Obtaining unrodded nodal parameters using the VERA rodded state points reduced maximum differences to 2 pcm and 0.003 in pin powers.


2020 ◽  
Vol 29 (09) ◽  
pp. 2030008
Author(s):  
J. B. Gupta ◽  
J. H. Hamilton

The Kr isotopes lying in between the lighter isotopes of (Zn, Ge and Se) and the heavier isotopes of (Sr and Zr) in the [Formula: see text]–80 region exhibit very interesting spectral features. The spectra of [Formula: see text]Kr isotopes display a striking contrast from those of Zn, Ge and Se isotopes. The role of spherical and oblate and prolate deformed subshell gaps at specific [Formula: see text] and [Formula: see text] and the resulting re-inforcement are strikingly evident in these contrasting features, with variation in [Formula: see text] or [Formula: see text]. The evolution of the spectral features in Kr isotopes with [Formula: see text] as reflected in the quadrupole deformation, [Formula: see text]-band structures, [Formula: see text]0 decay, [Formula: see text]2) values, [Formula: see text]-softness of the nuclear core and odd–even staggering in [Formula: see text]-bands is studied to explore the role of the under lying nuclear interactions. The correlations with odd–[Formula: see text] isotopes are explored. The shape co-existence displayed in some Kr isotopes is studied. The large deformation observed in the ground bands of [Formula: see text]Kr, as exhibited in the [Formula: see text]2) values, is especially interesting.


2020 ◽  
Vol 21 (14) ◽  
pp. 5065
Author(s):  
Sultan Alanazi ◽  
Mirjana Grujic ◽  
Maria Lampinen ◽  
Ola Rollman ◽  
Christian P. Sommerhoff ◽  
...  

Tryptase is a tetrameric serine protease located within the secretory granules of mast cells. In the secretory granules, tryptase is stored in complex with negatively charged heparin proteoglycans and it is known that heparin is essential for stabilizing the enzymatic activity of tryptase. However, recent findings suggest that enzymatically active tryptase also can be found in the nucleus of murine mast cells, but it is not known how the enzmatic activity of tryptase is maintained in the nuclear milieu. Here we hypothesized that tryptase, as well as being stabilized by heparin, can be stabilized by DNA, the rationale being that the anionic charge of DNA could potentially substitute for that of heparin to execute this function. Indeed, we showed that double-stranded DNA preserved the enzymatic activity of human β-tryptase with a similar efficiency as heparin. In contrast, single-stranded DNA did not have this capacity. We also demonstrated that DNA fragments down to 400 base pairs have tryptase-stabilizing effects equal to that of intact DNA. Further, we showed that DNA-stabilized tryptase was more efficient in degrading nuclear core histones than heparin-stabilized enzyme. Finally, we demonstrated that tryptase, similar to its nuclear localization in murine mast cells, is found within the nucleus of primary human skin mast cells. Altogether, these finding reveal a hitherto unknown mechanism for the stabilization of mast cell tryptase, and these findings can have an important impact on our understanding of how tryptase regulates nuclear events.


2020 ◽  
Vol 141 ◽  
pp. 107346 ◽  
Author(s):  
Helin Gong ◽  
Yingrui Yu ◽  
Qing Li ◽  
Chaoyu Quan

2020 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
A. R. Bodmer ◽  
S. Murall ◽  
Q. N. Usmanis

In part 1 the effect of nuclear core dynamics cm the binding energies of Λ hy­ pernuclei is discussed in the framework of variational correlated wave functions. In particular, we discuss a new rearrangement energy contribution and its effect on the core polarization. In part 2 we consider the interpretation of the Λ single-particle energy in terms of basic Λ-nuclear interactions using a local density approximation based on a fermi hypernetted chain calculation of the Λ binding to nuclear matter. To account for the data strongly repulsive 3-body AN Ν forces are required. Also in this framework we discuss core polarization for medium and heavier hypernuclei.


2019 ◽  
Vol 15 (S356) ◽  
pp. 342-344
Author(s):  
Zara Randriamanakoto

AbstractWe use low-frequency GMRT observations and 1.4 GHz VLA archival data to study the radio spectrum of a dying radio galaxy discovered in the field of ELAIS-N1. With a linear size of ˜ 100 kpc at a redshift z ˜ 0.33, the diffuse source J1615+5452 exhibits a steep spectral index and a convex radio spectrum. Its radio morphology also seems to lack compact features such as a nuclear core, relativistic jets and hotspots. We record a spectral curvature Δα ≍ -1 and a synchrotron age estimated between 34 - 70 Myr. These characteristics suggest that J1615+5452 is most likely a remnant radio AGN that has spent more than half of its total lifetime in the quiescence phase. The detection of such an elusive source is important since it represents the final phase in the evolution of a radio galaxy unless the nuclear core gets replenished with fresh particles and undergoes a restarting activity.


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