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In the early 1930's, Fermi wrote two papers in which he introduced the concepts of "scattering length" and "pseudopotential." Since that time, these terms have become universally associated with low energy scattering phenomena. Even though the two papers are very different—one in atomic physics, the other in neutron physics—a simple figure underlies both. The figure appears many times in Fermi's work. We review how the two papers came about and briefly discuss modern developments of the work that Fermi initiated with these two remarkable papers. [ABSTRACT FROM AUTHOR]

Neutron depolarization experiments have shown that the intragranular magnetic domain structure of polycrystalline ferrites exhibits a marked grain size dependence. Below a grain size of around $3~\mu \text{m}$ , the magnetic domain structure changes from the two-domain to the mono-domain state. Ferrites composed of mono-domain grains exhibit low dissipation at megahertz frequencies. This is attributed to the absence of intragranular domain wall movement, i.e., a microscopic origin for dissipation in ferrites has been identified. The implications of this clear observation and evidence for a transition from the mono- to two-domain state in ferrites for micromagnetic theory when a single particle becomes monodomain, as well as for the initial permeability mechanisms in polycrystalline ferrites, are discussed. [ABSTRACT FROM AUTHOR]

This paper present the impact on hardness assurance testing and the enhanced degradation of proton and neutron of the semiconductor device. In this work, it is shown that protons and neutrons can induce enhanced degradation in both trench and planar geometry power MOSFETs. Specifically, large shifts in current-voltage characteristics of some devices were observed at extremely low proton total dose levels (as low as 2 rad(SiO2)). These shifts induced significant increases (more than three orders of magnitude) in device "off" state leakage current. Neutron irradiations show similar degradation at equivalent fluence levels, even though neutrons do not deposit dose due to direct ionization. In addition, this increase in leakage current occurs at a much lower total dose level than expected based on 60Co gamma ray data. These data therefore suggest that the mechanism responsible for the enhanced degradation is a microdose effect associated with secondary particles produced through nuclear interactions between protons and neutrons and the materials in integrated circuits. The secondary particles deposit enough charge in the gate oxide to induce a parasitic drain to source leakage path in the transistor. Although the results are demonstrated for only trench and planar geometry power MOSFETs, microdose effects can impact the radiation response of other integrated circuit types. [ABSTRACT FROM PUBLISHER]

This paper is a review of the present status of neutrino mass physics, which grew out of an APS sponsored study of neutrinos in 2004. After a discussion of the present knowledge of neutrino masses and mixing and some popular ways to probe the new physics implied by recent data, it summarizes what can be learned about neutrino interactions as well as the nature of new physics beyond the Standard Model from the various proposed neutrino experiments. The intriguing possibility that neutrino mass physics may be at the heart of our understanding of a long standing puzzle of cosmology, i.e. the origin of matter-antimatter asymmetry is also discussed. [ABSTRACT FROM AUTHOR]

Neutron skyshine from Linac Coherent Light Source II 4 GeV electron beam operation at SLAC National Accelerator Laboratory can contribute to prompt radiation exposure to the public at distances far beyond the accelerator tunnel housing. One of the shielding design requirements at SLAC is that the annual dose to a member of the public is no more than 0.05 mSv y. This study uses Monte Carlo code FLUKA to simulate the generation of neutrons from 4 GeV electron beam losses on a thick copper target inside a generalized geometry of the Linac Coherent Light Source II Beam Transport Hall accelerator tunnel section. The effective dose from neutron skyshine was characterized as a function of both distance from the tunnel wall (up to 1 km away) and angle relative to the beam direction (between 0° and 180°). This new methodology for evaluating neutron skyshine dose is applicable to high-energy GeV-range electron accelerator facilities both at SLAC and elsewhere.

Fracture structures are important natural gas transport spaces in shale gas reservoirs, and their storage state in shale gas reservoirs seriously affects gas production and extraction efficiency. This work uses numerical modeling techniques to investigate the logging response law of the thermal and epithermal neutrons in the gas-containing fracture environment at various angles, applying neutron logging as a technical method. To increase the precision of the evaluation of the natural gas storage condition in shale gas reservoirs, the angle of the fractures' neutron logging data is analyzed. It is found that even in an environment with the same porosity of the fractures, there are significant differences in the logging results due to the different angles of the fracture alignment: 1. the neutron counts in the high-angle (70–90°) fracture environment are 2.25 times higher than in the low-angle (0–20°), but the diffusion area of the neutrons is only 10.58% of that in the low-angle (0–20°); 2. in the neutron energy spectrum, neutron counts are spreading to the high-energy region (7–13 MeV) along with the increase in the angle of the fracture, and the feature is especially prominent in the approximately vertical (60–90°) fracture environment, which is an increase of 528.12% in comparison with the counts in the approximately horizontal angle (0–30°) environment. The main reason for these differences is the variation in the volume of the fracture within the source radiation. This volumetric difference results from the variation in fracture angles (even though the fracture porosity is the same). In view of the above phenomenon, this paper proposes the concept of "effective fracture volume", which can intuitively reflect the degree of influence of fracture angle on neutron logging results. Further, based on the unique characteristics of shale gas reservoirs and neutrons, this paper provides important theoretical support for the modification of the porosity of the field operation, the evaluation of the physical characteristics of the gas endowment space, and the assessment. [ABSTRACT FROM AUTHOR]

This paper investigates the possibility of restoring the trajectory of fission fragments using thick targets that are opaque to the fragments, by analyzing the angular distribution of prompt neutrons. Employing thick targets in experimental studies with low-intensity neutron beams accelerate the accumulation of statistics, thereby facilitating the study of subtle effects, such as the rotation (ROT) effect which sheds light on the deformation and rotational behavior of fission fragments. The paper details the experimental techniques used, presents the results of neutron yield measurements from the fission of 235U with cold and “warm” (60 meV) neutrons in the range of angles from 0 to 360( (in 22.5( increments). The analysis of these is also presented. [ABSTRACT FROM AUTHOR]

Understanding the behaviour of a neutron spectrum with burnup is important for describing various phenomena associated with reactor operation. The quest to understand the neutron spectrum comes with a lot of questions. One question that is usually asked by students is: Does the neutron spectrum harden or soften with burnup? Most textbooks used by students do not provide a definite answer to this question. This paper seeks to answer this question using a 3D model of a standard 17 × 17 pressurised water reactor fuel assembly. Two cases were studied using the Serpent Monte Carlo code: the first considered the fuel assembly with constant boron concentration (traditionally found in many published papers), and the second considered boron iteration (where the boron concentration was reduced with burnup). Neutron spectra for the two cases at beginning of life and end of life were compared for spectral shifts. In addition, thermal spectral indices were used to assess spectrum hardening or softening with burnup. Spectral shifts to lower energies were observed in the thermal region of the neutron spectrum, whereas the fast region experienced no spectral shift. There was an increase in thermal spectral indices indicating that the spectrum became soft with burnup. [ABSTRACT FROM AUTHOR]

In this paper, an overview of wide-bandgap (WBG) semiconductors for radiation detection applications is given. The recent advancements in the fabrication of high-quality wafers have enabled remarkable WBG semiconductor device applications. The most common 4H-SiC, GaN, and β-Ga2O3 devices used for radiation detection are described. The 4H-SiC and GaN devices have already achieved exceptional results in the detection of alpha particles and neutrons, thermal neutrons in particular. While β-Ga2O3 devices have not yet reached the same level of technological maturity (compared to 4H-SiC and GaN), their current achievements for X-ray detection indicate great potential and promising prospects for future applications. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrated the biological effects of acute low-dose neutrons on the whole body of rats and investigated the impact of that level of neutron dose to induce an in vivo radio-adaptive response. To understand the radio-adaptive response, the examined animals were exposed to acute neutron radiation doses of 5 and 10 mSv, followed by a 50 mSv challenge dose after 14 days. After irradiation, all groups receiving single and double doses were kept in cages for one day before sampling. The electron paramagnetic resonance (EPR) method was used to estimate the radiation-induced radicals in the blood, and some hematological parameters and lipid peroxidation (MDA) were determined. A comet assay was performed beside some of the antioxidant enzymes [catalase enzyme (CAT), superoxide dismutase (SOD), and glutathione (GSH)]. Seven groups of adult male rats were classified according to their dose of neutron exposure. Measurements of all studied markers are taken one week after harvesting, except for hematological markers, within 2 h. The results indicated lower production of antioxidant enzymes (CAT by 1.18-5.83%, SOD by 1.47-17.8%, and GSH by 11.3-82.1%). Additionally, there was an increase in red cell distribution width (RDW) (from 4.61 to 25.19%) and in comet assay parameters such as Tail Length, (from 6.16 to 10.81 µm), Tail Moment, (from 1.17 to 2.46 µm), and percentage of DNA in tail length (DNA%) (from 9.58 to 17.32%) in all groups exposed to acute doses of radiation ranging from 5 to 50 mSv, respectively. This emphasizes the ascending harmful effect with the increased acute thermal neutron doses. The values of the introduced factor of radio adaptive response for all markers under study reveal that the lower priming dose promotes a higher adaptation response and vice versa. Ultimately, the results indicate significant variations in DNA%, SOD enzyme levels, EPR intensity, total Hb concentration, and RDWs, suggesting their potential use as biomarkers for acute thermal neutron dosimetry. Further research is necessary to validate these measurements as biodosimetry for radiation exposure, including investigations involving the response impact of RAR with varied challenge doses and post-irradiation behavior., (© 2024. The Author(s).)

Astronauts participating in lunar landing missions will encounter exposure to albedo particles emitted from the lunar surface as well as primary high-energy particles in the spectra of galactic cosmic rays (GCRs) and solar particle events (SPEs). While existing studies have examined particle energy spectra and absorbed doses in limited radiation exposure scenarios on and near the Moon, comprehensive research encompassing various shielding amounts and large SPEs on the lunar surface remains lacking. Additionally, detailed organ dose equivalents of albedo particles in a human model on the lunar surface have yet to be investigated. This work assesses the organ dose equivalents of albedo neutrons and albedo protons during historically large SPEs in August 1972 and September 1989 utilizing realistic computational anthropomorphic human phantom for the first time. Dosimetric quantities within human organs have been evaluated based on the PHITS Monte Carlo simulation results and quality factors of the state-of-the-art NASA Space Cancer Risk (NSCR) model, as well as ICRP publications. The results with the NSCR model indicate that the albedo contribution to organ dose equivalent is less than 3 % for 1 g/cm 2 aluminum shielding, while it increases to more than 30 % in some organs for 50 g/cm 2 aluminum shielding during exposure to low-energy-proton-rich SPEs., Competing Interests: Conflict of Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The radiotherapeutic 195m Pt is among the most effective Auger electron emitters of the currently studied radionuclides that have a potential theranostic application in nuclear medicine. Production of 195m Pt through double neuron capture of enriched 193 Ir followed by β - -decay to the radioisotope of interest carried out at the research reactor IBR-2 is described. Because of the high radiation background, radiochemical purification procedure of 195m Pt from bulk of iridium was needed to be developed and is detailed here as well. For the first time, cross section and resonance integral for the reaction 194 Ir(n,γ) 195m Ir were determined. Resonance neutrons contribution was established to exceed that of thermal neutrons, and resonance integral for the reaction 194 Ir(n,γ) 195m Ir is calculated to be 2900 b. Specific activity of 195m Pt was estimated to reach a value of 38.7 GBq/(g Pt) at IBR-2 by the end of bombardment (EOB)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Computed tomography has become a standard method to probe processes in porous media. Neutrons enabled us to better study the dynamics of hydrogeneous fluids in the matrix of dense and opaque materials. We review recent instrumentation and method improvements to the neutron imaging facilities NEUTRA and ICON at Paul Scherrer Institute. The improvements give us higher spatial resolution making it possible to follow finer details and faster acquisition to increase the CT volume capture rate. The combination with new reconstruction techniques improve the information output with less acquired projection data and hence providing higher volume rates. Bi-modality is a further option to provide more information about the sample and the processes taking place. These features make new neutron imaging experiments to investigate the fluid distribution in porous samples possible. We demonstrate the performance on a selection of experiments performed at our neutron imaging instruments. [ABSTRACT FROM AUTHOR]

Organic light-emitting diodes (OLEDs) are subjected to varying conditions of temperature during their lifetime. Using a combination of neutron reflectometry and in situ photoluminescence spectroscopy we show that layers typically found in OLEDs can interdiffuse. The diffusion is temperature dependent and it is found that the iridium(III) complexes can be remarkably mobile, even with relatively bulky alkyl groups attached to the ligand. [ABSTRACT FROM AUTHOR]

Carbon ions have unique physical and biological properties that allow for precise targeting of tumors while minimizing damage to surrounding healthy tissues. The emitted neutrons dominate the radiation field in the treatment room and pose challenges for radiological shielding. Concrete is extensively utilized in the construction of radiotherapy facilities due to its good shielding characteristics, and it can be easily poured into the desired shapes and thickness. The difference in composition of concrete affects the characteristics of neutron attenuation and activation performance. Therefore, the purpose of this study is to clarify the shielding properties and activation performances of four types of concrete for carbon ion therapy facilities. The Monte Carlo method is used to analyze the neutron spectra from thick targets upon carbon ion bombardment. Furthermore, the deep attenuation efficiency of the secondary neutron in different compositions of concrete is discussed. The shielding design is developed to ensure compliance with the prescribed dose limit outside the shielding during operation. Finally, the induced radioactivity in concrete is estimated for both short-term and long-term operation. The produced radionuclides inventories and depth profiling are determined. This study reveals the shielding and radioactivity issue of carbon ion therapy facilities and is expected to aid in the design or construction of similar facilities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

In this paper I discuss the first "multi-messenger" observations of a binary neutron star merger and kilonova. These observations, touted as "revolutionary," included both gravitational-wave and electromagnetic observations of a single source. I draw on analogies between astrophysics and historical sciences (e.g., paleontology) to explain the significance of this for (gravitational-wave) astrophysics. In particular, I argue that having independent lines of evidence about a target system enables the use of argumentative strategies-the "Sherlock Holmes" method and consilience-that help overcome the key challenges astrophysics faces as an observational and historical science., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Biological membranes are highly complex supramolecular assemblies, which play central roles in biology. However, their complexity makes them challenging to study their nanoscale structures. To overcome this challenge, model membranes assembled using reduced sets of membrane-associated biomolecules have been found to be both excellent and tractable proxies for biological membranes. Due to their relative simplicity, they have been studied using a range of biophysical characterization techniques. In this review article, we will briefly detail the use of fluorescence and electron microscopies, and X-ray and neutron scattering techniques used over the past few decades to study the nanostructure of biological membranes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

We discuss the quantum-bouncer experiment involving ultracold neutrons in a braneworld scenario. Extra-dimensional theories typically predict the strengthening of gravitational interactions over short distances. In this paper, we specifically study the anomalous gravitational interaction between the bouncing neutron and the reflecting mirror, resulting from hidden dimensions, and investigate the effects of this new interaction on the outcome of the quantum-bouncer experiment in the context of a thick brane model. This analysis allows us to identify which physical quantity of the extra-dimensional theory this neutron experiment is capable of constraining. Based on the experimental data, we found a new and independent empirical bound on the free parameters of the model: the higher-dimensional gravitational constant and a parameter related to a transverse width of the confined matter inside the thickbrane. This new bound is valid in scenarios with an arbitrary number of extra dimensions greater than two. In this manner, by considering the thickness of the brane, we have been able to extend previous studies on this topic, which were limited to models with few codimensions, due to non-computability problems of power-law corrections of the gravitational potential. [ABSTRACT FROM AUTHOR]

We present the first machine learning-based autonomous hyperspectral neutron computed tomography experiment performed at the Spallation Neutron Source. Hyperspectral neutron computed tomography allows the characterization of samples by enabling the reconstruction of crystallographic information and elemental/isotopic composition of objects relevant to materials science. High quality reconstructions using traditional algorithms such as the filtered back projection require a high signal-to-noise ratio across a wide wavelength range combined with a large number of projections. This results in scan times of several days to acquire hundreds of hyperspectral projections, during which end users have minimal feedback. To address these challenges, a golden ratio scanning protocol combined with model-based image reconstruction algorithms have been proposed. This novel approach enables high quality real-time reconstructions from streaming experimental data, thus providing feedback to users, while requiring fewer yet a fixed number of projections compared to the filtered back projection method. In this paper, we propose a novel machine learning criterion that can terminate a streaming neutron tomography scan once sufficient information is obtained based on the current set of measurements. Our decision criterion uses a quality score which combines a reference-free image quality metric computed using a pre-trained deep neural network with a metric that measures differences between consecutive reconstructions. The results show that our method can reduce the measurement time by approximately a factor of five compared to a baseline method based on filtered back projection for the samples we studied while automatically terminating the scans. [ABSTRACT FROM AUTHOR]

This document is a correction notice for a published paper titled "Tritium Desorption Behavior and Microstructure Evolution of Beryllium Irradiated at Low Temperature Up to High Neutron Dose in BR2 Reactor." The authors have made several corrections to the figures, tables, and text in the paper. The changes include removing and adding figures, correcting correlations, clarifying the tritium content in irradiated beryllium, and updating the data availability statement. The authors state that these corrections do not affect the scientific conclusions of the paper. [Extracted from the article]

This paper concerns the correlation of hard x-ray and neutron signals, which were recorded with scintillation detectors oriented in the axial and radial directions, in a comparison with interferometric and extreme-ultraviolet radiation frames, as recorded within the plasma focus (PF)-1000 facility operated with a deuterium filling. The considered signals showed two different phases. In the initial phase, the fusion neutrons are mainly produced by deuterons moving dominantly downstream during the disruption of a pinch constriction (lasting tens nanoseconds). In the later phase (usually after about 100 ns), the fusion neutron emission reaches its maximum in the radial directions. This emission (lasting 100–200 ns) is caused by the fast deuterons moving in both the downstream and radial directions. It correlates usually with a decay of dense plasma structures in remnants of the expanding pinch column. This can be explained by a decay of internal magnetic fields. The neutron signal is usually composed of several sub-pulses of different energies. It was deduced that the primary deuterons producing the observed fusion neutrons undergo a regular and repeated temporal, directional, and energy evolution. [ABSTRACT FROM AUTHOR]

There are many studies in Odd–Even staggering (OES) of nuclear masses, but the research on nuclear masses by using the systematicness of OES is indeed very few. In this work, we analyze the relationship among the four neighboring nuclei based on the OES of nuclide chain with the same number of neutrons in atomic mass evaluation database (AME2016 database). Our purpose in this paper is to describe an empirical formula with one constant for OES of nuclear masses that can be useful in describing and predicting nuclear masses with mass number A ≥ 1 0 0. With the empirical formula and AME2016 database, the root-mean-square deviation (RMSD) of the nuclei that we have successfully obtained 172 keV for A ≥ 1 0 0 (the RMSD is 140 keV for A ≥ 1 5 8). This paper also uses Levenberg–Marquart (L-M) neural network approach to study the OES of nuclear masses (A ≥ 1 0 0 , RMSD ≃ 1 4 3 keV; A ≥ 1 5 8 , RMSD ≃ 1 1 9 keV). The results show that the RMSD of nuclear masses for A ≥ 1 0 0 based on neural network approach 30 keV decreases than that based on empirical formula (the accuracy is increased by about 17%). In addition, the predicted values based on the empirical formula and L-M neural network approach are consistent with the values in AME2020 database, and the difference between our predicted values based on AME2016 database and experimental values measured in recent years is small. These results show that the new relation for nuclear masses has good simplicity, accuracy and reliability. Accurate nuclear mass is helpful to the research of nuclear physics, nuclear technology and astrophysics. [ABSTRACT FROM AUTHOR]

With neutron diffraction, the local stress and texture of metallic components can be analyzed non-destructively. For both, highly accurate positioning of the sample is essential, requiring the measurement at the same sample location from different directions. Current sample-positioning systems in neutron diffraction instruments combine XYZ tables and Eulerian cradles to enable the accurate six-degree-of-freedom (6DoF) handling of samples. However, these systems are not flexible enough. The choice of the rotation center and their range of motion are limited. Industrial six-axis robots have the necessary flexibility, but they lack the required absolute accuracy. This paper proposes a visual servoing system consisting of an industrial six-axis robot enhanced with a high-precision multi-camera tracking system. Its goal is to achieve an absolute positioning accuracy of better than 50 μ m. A digital twin integrates various data sources from the instrument and the sample in order to enable a fully automatic measurement procedure. This system is also highly relevant for other kinds of processes that require the accurate and flexible handling of objects and tools, e.g., robotic surgery or industrial printing on 3D surfaces. [ABSTRACT FROM AUTHOR]

In response to the significant dependency on empirical judgment in measuring the prompt neutron decay constant with the traditional Rossi-alpha method and the issue of requiring an excessive number of detectors with the DMD-Rossi-alpha method, this paper introduces a calculation method for the prompt neutron decay constant based on a combination of Latin Hypercube Sampling (LHS), Dynamic Mode Decomposition (DMD), and the Rossi-alpha method. Initially, the method uses LHS to expand the sample dataset of neutron noise data to reduce the number of detectors required. It then employs the Rossi-alpha method to construct a Rossi-alpha distribution model from neutron noise data. Finally, it utilizes DMD for feature extraction from the Rossi-alpha distribution model, thereby determining the prompt neutron decay constant. Research findings demonstrate that, by simulating the KUCA facility using RMC3.5 in a near-critical state, the relative error of the α value calculated by the LHS-DMD-Rossi-alpha method model is 9% less than that calculated by the Rossi-alpha method. This approach, capable of enhancing the precision of measuring the prompt neutron decay constant with just a single detector, holds significant theoretical value and engineering significance for the advancement of reactor physics and experimental techniques. [ABSTRACT FROM AUTHOR]

Neutron star observations, as well as experiments on neutron-rich nuclei, used to motivate one to look at degenerate nuclear matter from its extreme, namely, pure neutron matter. As an important next step, impurities and clusters in dilute neutron matter have attracted special attention. In this paper, we review in-medium properties of these objects on the basis of the physics of polarons, which have been recently realized in ultracold atomic experiments. We discuss how such atomic and nuclear systems are related to each other in terms of polarons. In addition to the interdisciplinary understanding of in-medium nuclear clusters, it is shown that the quasiparticle energy of a single proton in neutron matter is associated with the symmetry energy, implying a novel route toward the nuclear equation of state from the neutron-rich side. [ABSTRACT FROM AUTHOR]

This paper investigates the neutron diffusion model with two energy groups in spherical reactors. In particular, the integer-order two energy groups neutron diffusion model in spherical reactors is resolved using the Laplace transform method by regarding the spherical radius r as a time domain. Next, we transform the neutron diffusion model into fractional-order versions using the Caputo differentiator, resulting in what is referred to as the fractional-order two-energy-group neutron diffusion model. To address this fractional-order system, we introduce a novel approach to reduce a system of 2a -order to a duplicated system of a -order, where 0 <α 1. This converted system is then solved using one of the recent modifications of the fractional Euler method called the Modified Fractional Euler Method (MFEM). Several numerical simulations are depicted to verify our findings. [ABSTRACT FROM AUTHOR]

The isotopic shifts of 149Sm–150Sm and 157Gd–158Gd have often been observed in meteorites and lunar surface materials, because they result from the neutron-capture reactions associated with secondary neutrons produced by cosmic-ray irradiation. While the Sm and Gd isotopic shifts can mainly be used for the estimation of thermal neutron fluences that of 167Er–168Er has recently been applied in the estimation of epithermal neutron fluences. The systematic isotopic dataset of Sm, Gd and Er helps us to consider the details of planetary materials' cosmic-ray exposure conditions using the balance of the fluences between thermal and epithermal neutrons. This paper reviews a series of isotopic variations of Sm, Gd, and Er in association with neutron-capture reactions for the application of planetary sciences. As a new attempt and possibility for better understanding the neutron fluence and its energy distribution, the use of Yb isotopic variation is then discussed using two different data sources, namely lunar regolith and the Oklo natural reactors. Finally, the preliminary result for the precise isotopic measurement of Yb is presented from the viewpoint of chemical separation and instrumental improvement. [ABSTRACT FROM AUTHOR]

The existing interpretation models for the time spectrum of impulse neutron oxygen activation require interpreters to select the peak range or background range manually from the time spectrum curve, and there is no adaptive interpretation model that can determine the peak range or background range. In this paper, an adaptive selection rule for background segment is proposed, and a semiautomatic interpretation model is constructed by combining background segment interpretation model. Firstly, the interpretation operator selects the time spectrum curve, then the algorithm program adaptively determines the background segment according to the rules, and then calculates and displays the transit time and volume flow according to the background segment interpretation model. The processing results of the measured data show that the interpretation model in this paper not only retains the interpretation precision of the background interpretation model, but also reduces the labor intensity of the interpretation operator, realizing the semiautomatic interpretation of the time spectrum. [ABSTRACT FROM AUTHOR]

In heavy-ion-induced projectile fragmentation reactions at Fermi energies vast amount of different nuclides far from stability line are born. These neutron or proton-reach isotopes can be used as secondary beams to obtain even more exotic new isotopes or to study nuclear interactions of halo nuclei and their radii and other yet unsolved scientific problems. Radioactive isotopes produced in fragmentation reactions can be used in medical and industrial applications. In this paper we present velocity and isotope distributions of fragments from Na to Ca obtained in the collision of Ar beam of 36.5 MeV on Be target on COMBAS mass-spectrometer at FLNR, JINR. We compare the experimental results with the calculations fulfilled in combined transport-statistical model and show good agreement between them. [ABSTRACT FROM AUTHOR]