An edge Lyman-alpha-based beam emission spectroscopy(LyBES)diagnostic,using a heating NBI(neutral beam injection)system,is currently under development on the HL-2A *** 20-channel edge LyBES,which is intended to measur...
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An edge Lyman-alpha-based beam emission spectroscopy(LyBES)diagnostic,using a heating NBI(neutral beam injection)system,is currently under development on the HL-2A *** 20-channel edge LyBES,which is intended to measure the density fluctuation in plasma edge(from R=1960 mm to R=2026 mm)with an improved spatial resolution of 3.3 mm,is a complement to the existing conventional beam emission spectroscopy(BES)*** this article,we introduce the progress of LyBES diagnostic,including the collection optics,the monochromator,and the detector *** reflectance of the collection mirrors is measured to be~82%at 122 nm,and the aberration geometrical radius of the collection optics is tested to be~150μm in the aimed *** linear dispersion of the LyBES monochromator is designed to be~0.09 nm mm^(-1).The bandwidth of the detector system with the 5×10^(7)V A^(-1)preamplifier gain is measured to be~280 kHz,and the peak-to-peak noise of the detector system is tested to be~16 *** finalized design,components development and testing of the LyBES diagnostic have been completed at present,and an overall performance of the LyBES diagnostic is to be confirmed in the next HL-2A campaign.
To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission *** the trans...
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To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission *** the transmission reconstruction equation and the Monte Carlo program Geant4,an innovative virtual trajectory length model was *** model integrated the solving process for the trajectory length and detection efficiency within the same *** mitigate the influence of the angular distribution ofγ-rays emitted by the transmitted source at the detector,the transport processes of numerous particles traversing a virtual nuclear waste barrel with a density of zero were ***,a certain amount of information was captured at each step of particle ***,the model addressed the nonuniform detection efficiency of the detector end face by considering whether the energy deposition of particles in the detector equaled their initial *** models were established to validate the accuracy and reliability of the virtual trajectory length *** 1 was a simplified nuclear waste barrel,whereas Model 2 closely resembled the actual structure of a nuclear waste *** results indicated that the proposed virtual trajectory length model significantly enhanced the precision of the trajectory length determination,substantially increasing the quality of the reconstructed *** example,the reconstructed images of Model 2 using the“point-to-point”and average trajectory models revealed a signalto-noise ratio increase of 375.0%and 112.7%,***,the virtual trajectory length model proposed in this study holds paramount significance for the precise reconstruction of transmission ***,it can provide support for the accurate detection of radioactive activity in nuclear waste barrels.
Measurement of the cross-sections of the ^(79)Br(n,2n)^(78)Br,^(81)Br(n,p)^(81)mSe,^(81)Br(n,α)^(78)As,and ^(79)Br(n,α)^(76)As reactions was performed at specific neutron energies,precisely,13.5±0.2,14.1±0...
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Measurement of the cross-sections of the ^(79)Br(n,2n)^(78)Br,^(81)Br(n,p)^(81)mSe,^(81)Br(n,α)^(78)As,and ^(79)Br(n,α)^(76)As reactions was performed at specific neutron energies,precisely,13.5±0.2,14.1±0.2,14.4±0.2,and 14.8±0.2 MeV,relative to the standard ^(93)Nb(n,2n)^(92)mNb and ^(27)Al(n,α)^(24)Na reference reactions using offlineγ-ray spectrometry and neutron *** neutrons were generated at the China Academy of engineeringphysics via a ^(3)H(d,n)^(4)He reaction using the K-400 Neutron Generator equipped with a solid ^(3)H-Ti based *** activity of the reaction produce was obtained using a high-purity germanium *** cross-sections of the(n,2n),(n,p),and(n,α)reactions on the bromine isotopes were measured in the 13–15 MeV neutron energy *** covariance analysis approach was employed for a thorough inspection of any uncertainties within the measured cross-section data.A discussion and comparison of the observed outcome were carried out with previously published data,especially with the results of the JENDL-4.0,JEFF-3.3,TENDL-2019,and ENDF/B-VIII.0 data libraries,along with the theoretical excitation function curve derived by employing the TALYS-1.95 *** cross-section restrictions for the investigated processes in the 13–15 MeV neutron energy range will be obtained using the current findings,which will help to raise the caliber of associated ***,the parameters of relevant nuclear reaction models can be verified using this data.
Heavy-ion collisions at near-barrier energies provide a crucial pathway for investigating nucleon correlations and clustering structures. Recent experimental results showed that the valence neutrons in light projectil...
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Heavy-ion collisions at near-barrier energies provide a crucial pathway for investigating nucleon correlations and clustering structures. Recent experimental results showed that the valence neutrons in light projectiles obviously enhance the α transfer. This finding is extremely puzzling and fascinating, because it violates the ground-state Q value systematics unexpectedly. In this work, the time-dependent Hartree-Fock approach is utilized to investigate the cluster transfer. By comparing the reactions C12,14+Bi209, we discover that above puzzling behavior is because of the strong correlation between isospin diffusion and clustering. Our calculations clearly show that the equilibrium of neutron-to-proton ratio strongly inhibits the clustering. This work opens a prospect for investigating the clustering in an open quantum system.
In this study,measurements of the^(128)Te(n,2n)^(127m,g)Te reaction cross sections and the computation of the isomeric cross section ratio were performed around the neutron energy of 13−15 *** used aγ-ray spectrometr...
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In this study,measurements of the^(128)Te(n,2n)^(127m,g)Te reaction cross sections and the computation of the isomeric cross section ratio were performed around the neutron energy of 13−15 *** used aγ-ray spectrometric technique to conduct the *** neutron energy was produced by the^(3)H(d,n)^(4)He *** the^(128)Te(n,2n)^(127m,g)Te reaction,the excited state,ground state,total cross section,and isomeric cross section ratio were determined using the TALYS-1.96 code,a theoretical nuclear model that allows for variations in density *** initial experimental data,assessed nuclear data,and theoretical calculations based on the TALYS-1.96 algorithm were compared with the measurement *** new data produced by this study are essential for validating nuclear models and establishing parameters for nuclear reactions.
To support education and research activities using the Triga Kartini research reactor, a neutron flux reader connected to the NLW-2 power channel has been built using ESP32. ESP32 is a cheap, multi-functional device t...
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Voidage(porosity or void fraction)in packed particles(or pebbles)is of fundamental importance in calculating the pressure drop,obtaining the drag,predicting the bed permeability,estimating the neutron streaming,*** th...
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Voidage(porosity or void fraction)in packed particles(or pebbles)is of fundamental importance in calculating the pressure drop,obtaining the drag,predicting the bed permeability,estimating the neutron streaming,*** the case when particles are deformed,a method of voidage correction during the packing state is proposed using a Discrete Element Method(DEM)simulation of 3D pebble flow inside a bed of cycloidal base.A function to evaluate the remaining volume of a pebble intercepted by horizontal and vertical planes is proposed for voidage *** that,the process of solving voidage distribution is provided in *** this method,the voidage inside the cycloidal-base pebble bed is obtained to refer to reported similar data for *** method can be potentially used for dynamical voidage calculation in CFD-DEM simulation which can get suitable voidage distribution after the correction.
The Cooling Storage Ring of the Heavy Ion Research Facility in Lanzhou(HIRFL-CSR)was constructed to study nuclearphysics,atomic physics,interdisciplinary science,and related *** External Target Facility(ETF)is locate...
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The Cooling Storage Ring of the Heavy Ion Research Facility in Lanzhou(HIRFL-CSR)was constructed to study nuclearphysics,atomic physics,interdisciplinary science,and related *** External Target Facility(ETF)is located in the main ring of the *** gamma detector of the ETF is built to measure emitted gamma rays with energies below 5 MeV in the center-of-mass frame and is planned to measure light fragments with energies up to 300 *** readout electronics for the gamma detector were designed and *** readout electronics consist of thirty-two front-end cards,thirty-two readout control units(RCUs),one common readout unit,one synchronization&clock unit,and one sub-trigger *** using the real-time peak-detection algorithm implemented in the RCU,the data volume can be significantly *** addition,trigger logic selection algorithms are implemented to improve the selection of useful events and reduce the data *** test results show that the integral nonlinearity of the readout electronics is less than 1%,and the energy resolution for measuring the 60 Co source is better than 5.5%.This study discusses the design and performance of the readout electronics.
In this study, we developed a neural network that incorporates a fully connected layer with a convolutional layer to predict the nuclear charge radii based on the relationships between four local nuclear charge radii....
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In this study, we developed a neural network that incorporates a fully connected layer with a convolutional layer to predict the nuclear charge radii based on the relationships between four local nuclear charge radii. The convolutional neural network(CNN) combines the isospin and pairing effects to describe the charge radii of nuclei with A ≥ 39 and Z ≥ 20. The developed neural network achieved a root mean square(RMS) deviation of 0.0195 fm for a dataset with 928 nuclei. Specifically, the CNN reproduced the trend of the inverted parabolic behavior and odd–even staggering observed in the calcium isotopic chain, demonstrating reliable predictive capability.
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