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nEXO is a proposed search for neutrinoless double beta decay (0vββ) of 136Xe. The experiment is planning to utilize isotopically enriched xenon both as source and detection medium. Radon daughters produced by radon decays in the air can plate out on material surfaces during detector assembly and handling. The alpha particles they emit can interact with low-Z materials nearby and produce fast neutrons. These neutrons can in turn produce 137Xe when captured by 136Xe contained in the nEXO detector medium. The subsequent beta decay of 137Xe (Q = 4173 keV) can mimic 0vββ in nEXO. This paper describes simulation studies performed to estimate the background in nEXO produced by radon daughters. We will also discuss the allowed amounts of radon daughters on material surfaces in order to meet nEXO's stringent background requirements. [ABSTRACT FROM AUTHOR]

The Institute of Nuclear and Physical Engineering is currently developing a special laboratory, the Laboratory of Neutron Applications, where a DD type neutron generator is planned to be purchased and used for research purposes. As the equipment will be installed in a new facility, shielding materials will have to be utilized, to minimize the dose rate obtained by the personnel working with the generator as well as all workers of the faculty, who could potentially get close to the laboratory. The selection of shielding materials is complicated by the fact, that the room is situated partially underground on special pillars with limited load capacity, therefore the used shielding must be light and cheap. In this paper we are comparing the shielding performance of available light materials with the certified Neutronstop shielding blocks, based on the measurement conducted at the STU Mini Labyrinth and simulation performed in the SCALE6 system. The paper includes results of the neutron disappearance XS and the half-value-thickness of selected materials, the dose map around the Mini Labyrinth and a simple economic feasibility estimation for the Laboratory of Neutron Applications. [ABSTRACT FROM AUTHOR]

This paper presents the description of the preparation of aggregate irradiation experiment including the choice of sample types and preliminary numerical prediction of aggregate RIVE and damage under defined conditions for the research reactor LVR-15. Ten different samples from four countries were selected for the experimental investigation. The preliminary numerical analysis was performed for granite as the aggregate with the highest radiation-induced volumetric expansion (RIVE). Based on the prediction, the highest RIVE of 4.54 % at high-dose neutron fluence (0.585·1020 n/cm2, with energy E>10 keV) is expected. Thus, taking into account the sample size, the inner diameter of the irradiated capsule should be about 11 mm. The aggregate samples with the highest RIVE (granite) are expected to be damaged significantly even after irradiation to low-dose neutron fluence (0.208·1020 n/cm2, with energy E>10 keV) which will be captured during the post-irradiation examination. [ABSTRACT FROM AUTHOR]

The Mini Labyrinth experiment is a simple neutron and gamma shielding experiment developed at Slovak University of Technology (STU), inspired by the ALARM-CF-AIR-LAB-001 ICSBEP benchmark. Compared to the original Labyrinth, which was made from concrete blocks and had dimension of several meters, the STU Mini Labyrinth is approximately ten times smaller and consists of NEUTRONSTOP shielding blocks. So far, several versions and modifications of the Mini Labyrinth have been investigated, currently the V2-25-L version is used for code evaluation. This version uses a PuBe neutron source loaded in the entrance of the Mini Labyrinth, a plastic tank filled with light water moderator and the NuDET plastic scintillation neutron detector, which can be placed around the experimental workplace. This detector has a significant role in the experiment since it is a calibration apparatus and provides real time data on the rates of ambient dose equivalents of neutron radiation. On the other hand, as it is a certified commercial product, the response function of this detector is unknow, which makes a significant challenge of verifying the measured data with computer codes. This paper presents a result of a series of measurements with the NuDET detector performed at STU and discusses the options, how to verify the experimental results by the SCALE6 system in the most effective way. [ABSTRACT FROM AUTHOR]

The new solid state track detector analysis system for neutron dosimetry and radon measurement TASLImage™ was installed at the Slovak University of Technology, Bratislava. This paper describes the test of its performance in the measurement of neutron doses. The linearity of the response of poly allyl diglycol carbonate (PADC) detectors was tested for two regions of obtained doses, 27-378 µSv and 0.5 - 3 mSv. Results were compared to H*(10) ambient dose equivalent measured by the NuDET-ENE neutron detector. [ABSTRACT FROM AUTHOR]

The paper aims to study the quadrupole deformation and deformation energy curves of , even-even S 50 94 − 168 n isotopes (from the neutron to proton drip lines) which is one of the most interesting isotopic chains in the periodic table. The results are carried out in the framework of the Hartree-Fock-Bogoliubov (HFB) method with the HFB9 Skyrme force by using the HFBTHO code version (3.00) and compared with the available values of Finite Range Droplet Macroscopic model (FRDM), Relativistic Mean Field (RMF) theory. Sn isotopes of A<144 remain robustly spherical till N reaches 144 except for some nuclei where the deformation is quite small. Nuclei above this neutron number show an interesting change to prolate shape. Overall, An agreement is found between our calculations and other models. [ABSTRACT FROM AUTHOR]

In this paper, some nuclear features of some neutron-rich Al isotopes chain with neutron numbers N=14-22 near the island of inversion N=20 were investigated. The goal of this study was to verify the presence and magnitude of the inversion nature as the number of neutrons increases in these nuclei. For this purpose, the non-relativistic Hartree- Fock (HF) approach based on Skyrme parameterizations in two model space; sd with USDA interaction and sdpf with SDPFMU interaction was used. The results were compared with the available experimental data from NNDC and Ref. [1-3]. They support the validity of both the sd model for 28-32Al with normal ground state configuration, and sdpf model for 33&34Al with intruder ground state configuration. [ABSTRACT FROM AUTHOR]

Neutrons can induce background events in underground experiments looking for rare processes. Neutrons in a MeV range in deep underground laboratories are produced in spontaneous fission processes and (α, n) reactions. A number of computer codes are available to calculate cross-sections of (α, n) reactions, branching ratios to various states and neutron yields. We have used the SOURCES4 code to calculate neutron yields and energy spectra with input cross-sections and branching ratios taken from experimental data and calculations based on EMPIRE2.19/3.2.3 and TALYS1.9. We report here a comparison of SOURCES4 calculations with experimental data obtained with alpha beams with fixed energies. [ABSTRACT FROM AUTHOR]

To license the advanced gas-cooled fast reactor design, sufficient data with associated uncertainties should be known about its safety and operational capability. The relevant core parameters intuitively depend on the actual fuel isotopic composition which develops during a reactor operation. In practice, the prediction accuracy of burnup calculations serves as the basis for the future precise estimation of a core lifetime and other safety-based core characteristics. The present study quantifies nuclear data induced uncertainties of nuclide concentrations and multiplication factors in GFR 2400 demonstrator ALLEGRO utilizing the SCALE system, where the TRITON sequence is used with the KENO stochastic solver. The super-sequence SAMPLER module that implements stochastic techniques is used to assess the uncertainty in computed results. The propagation of uncertainties in neutron cross-section and fission yields is studied through the depletion calculation of 2D heterogeneous ALLEGRO-MOX fuel, where 150 cases with uncertain parameters are computed and the results are evaluated by an auxiliary tool. Achieved results confirmed the high final uncertainties in multiplication factor and nuclide concentrations important for criticality safety (239Pu, 238U, 241Pu) and decay heat (241Am) production. [ABSTRACT FROM AUTHOR]

This study demonstrates some nuclear properties that have been calculated of 58-60Ni nuclei such as positive energy levels ,electric quadrupole transitions, intrinsic quadrupole moment and factors of deformation. Nushell@MSU code was utilized for f5p model space with Van Hienen - Chung -Wildenthal (f5pvh) interaction. The calculations are carried out by utilizing three sets of effective charges obtained from Bohr - Mottelson model also default and appropriate effective charges for valance nucleons(protons and neutrons). A comparison has been made between theoretic effects with the available experimental data. The comparison shows that the energy levels , transition probabilities, intrinsic quadrupole moment and quadrupole deformation parameter are agreed well especially at effective charges of Bohr - Mottelson model and appropriate effective charges. [ABSTRACT FROM AUTHOR]

The author discusses some of the challenges that future nuclear modeling may face in order to improve the description of the nuclear structure. One challenge is related to the need for A-body nuclear interactions justified by various contemporary nuclear physics studies. Another challenge is related to the discrepancy in the NNN contact interaction parameters for 3He and 3H that suggests the need for accurate proton and neutron masses in the future precision calculations. [ABSTRACT FROM AUTHOR]