Vol.29,

With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr₃:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration. In the algorithm, the full width at half maximum (FWHM) of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ¹⁵²Eu, ¹³⁷Cs, and ⁶⁰Co sources were detected by a LaBr₃:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ±2 channels and the relative error of peak area was approximately within 0.96%–6.74%. Finally, a ¹³³Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.

390

We have studied the gamma and X-ray radiation compatibility of Ti based alloys such as Ti-37Ta-26Hf-13Zr-24 (wt.%) [Alloy 1], Ti-40Ta-22Hf-11.7Zr-26.3 (wt.%) [ Alloy 2], Ti-45Ta-18.4Hf-10Zr-26.6 (wt.%) [ Alloy 3], Ti-50Ta-15Hf-8Zr-27 (wt.%) [Alloy 4], Ti-55Ta-12Hf-7Zr-26 (wt.%) [Alloy 5], and Ti-60Ta-10Hf-5Zr-25 (wt.%) [Alloy 6]. Gamma and X-ray radiation compatibility is studied by evaluating the mass attenuation coefficient, mean free path, HVL, TVL effective atomic number, effective electron density, exposure buildup factor, and relative dose. We have compared these parameters for studied alloys with that of arteries. The alloys Ti-55Ta-12Hf-7Zr-26 and Ti-60Ta-10Hf-5Zr-25 have added properties such as gamma/ X-ray radiation compatibility, high elastic admissible strain, high mechanical strength, and excellent biocompatibility. Hence we may suggest that, among Ti-Ta-Hf-Zr alloys, these alloys are best materials for coronary stent applications.

450

The world's first full Experimental Advanced Superconducting Tokamak (EAST) is designed with the auxiliary heating method of neutral beam injection (NBI) system. Beam collimators are arranged on both sides of the beam channel for absorbing the divergence beam during the beam transmission process in the EAST-NBI system. The Gas Baffle Entrance Collimator (GBEC) is a typical high-heat-flux component located at the entrance of gas baffle. An efficient and accurate analysis of its thermodynamic performance is of great significance to explore the working limit and to ensure safe operation of the system under a high-parameter steady-state condition. Based on the thermo-fluid coupled method, thermodynamic analysis and simulation of GBEC is performed to get the working states and corresponding operating limits at different beam extraction conditions. This study provides a theoretical guidance for the next step to achieve long pulse with high power experimental operation, and has an important reference to ensure the safe operation of the system.

515

Nanocomposite CrC/hydrogenated amorphous carbon (nc-CrC/a-C:H) coatings were deposited by a hybrid beams system comprised of a hollow cathode ion source (HCIS) and a cathodic arc ion-plating unit with varying H₂ flow rates. The influences of H₂ flow rates on the morphologies, microstructures, and properties of the coatings were systematically studied. The morphologies and microstructures of the coatings were characterized by SEM, AFM, XPS, Raman, GIXRD, and HRTEM. The mechanical and tribological properties were measured by a nano-indenter, scratch tester, and ball-on-disc tribometer. The wear tracks were evaluated using 3D-profilometer, optical microscope, and EDS analysis. It has been found that a moderate H₂ flow rate can effectively smooth the surface, enlarge the fraction of a sp³ bond, and improve the properties. The coating exhibits the highest hardness and elastic modulus at the H₂ flow rate of 40 sccm. A superior combination of adhesion strength, friction coefficient, and wear resistance can be achieved at the H₂ flow rate of 80 sccm.

402

The nonlinear fractional point reactor kinetics equations in the presence of Newtonian temperature reactivity feedback with a multi-group of delayed neutrons, which describes the spectrum behavior of neutron density into the homogenous nuclear reactors, is developed. This system is one of the most important stiff coupled nonlinear fractional differentials for nuclear reactor dynamics. The generalization of Taylor’s formula that involves Caputo fractional derivatives is developed in an attempt to overcome the difficulty of the stiffness of the nonlinear fractional differential model. Moreover, the general fractional derivatives are calculated analytically throughout this work. Furthermore, the local and global estimated errors were analyzed, which suggest that the error quantification should take into account the possible grow in time of the error. This observation provides a motivation for going beyond more classical local-in-time concepts of error (Local Truncation Error). The neutron density response with time is analyzed for the anomalous diffusion, sub-diffusion, and supper-diffusion processes.

461

In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_th modular natural circulation lead-cooled fast reactor, developed by University of Science and Technology of China. The flow blockage shall cause a degradation of the heat transfer between the fuel assembly and the coolant potentially, which can eventually result in the clad fusion. An analysis of core blockage accidents in a single assembly is of great significance for LFR. Such scenarios are investigated by using the best estimation code RELAP5. Reactivity feedback and axial power profile are considered. The cross-section fraction of blockage, axial position of blockage, and blockage developing time are discussed. The cladding material failure shall be the biggest challenge, and shall be a considerable threat for integrity of the fuel assembly if the cross-section fraction of blockage is over 94%. The blockage-developing time only affects the accident progress. The consequence will be more serious if the axial position of a sudden blockage is closer to the core outlet. The method of analysis procedure can also be applied to analyze similar transient behaviors of other fuel type reactors.

497

We propose a system for remote measurement of low-energy radiation, which is implemented using an ARM board and a ZigBee module. The ARM STM32F103 board employs a horizontal and vertical moving CMOS camera for front-end data acquisition. The camera can detect radiation over different coordinates given by latitude and longitude in a determined area. For image processing, we used the subtraction–summation algorithm based on gradient multiplication and edge detection. Compared to algorithms such as the max gray-scale value, subtraction–summation, and whole summation, the improved subtraction–summation algorithm filters noise and removes the background gray-scale value of the whole image to attain higher accuracy, stronger anti-interference ability, and better consistency to determine the radiation dose. We dedicated one port of the transmission module to send data through the STM32F103 board, whereas another port is connected to the ZigBee module for data reception. By employing this architecture, we achieved low power consumption and fast response in the remote data transmission. Overall, the proposed system performs the remote measurement of low-energy radiation with stability and reliability, which is required for critical scenarios such as the remote detection of nuclear radiation.

335

The first domestic inorganic scintillator, Cs₂ LiYCl₆:Ce³⁺ (CLYC), was grown at Beijing Glass Research Institute using the vertical Bridgman method. In this work, we evaluated the performance of this new CLYC crystal in terms of its gamma-ray energy resolution and pulse shape discrimination (PSD) capability between neutrons and gamma rays. The decay times associated with different scintillation mechanisms were obtained by fitting decay functions to the neutron and gamma-ray waveform structures. We found an energy resolution of ~4.5% for 662-keV gamma rays and efficient neutron/gamma PSD with a figure of merit of ~2.6. Under gamma-ray excitation, there is an ultrafast scintillation mechanism in CLYC with a decay time of approximately 2 ns, whereas there is no evidence of ultrafast decay under thermal neutron excitation. This work contributes to promotion of domestic development of CLYC.

609

A new wide-range fast readout system capable of adaptive identification is designed for wire scanners, which are used to measure beam profiles and emittance. This system is capable of handling varying current signals with Gaussian distributions and current pulses up to 1000 counts/s, as well as an input current range of 1 nA–1 mA. When tested, the resolution was found to exceed 3.68% for full scale, the nonlinearity was found to be less than 0.11%, and the measurement sensibility was found to be less than 5 pA. We believe that the system will play a crucial role in improving the measurement accuracy of beam diagnosis and the efficiency of accelerator operation, as well as decreasing the time required for beam tuning. This system was applied to the beam diagnosis of an injector II prototype for an accelerator-driven subcritical system (ADS), and produced excellent measurement results. A description of the adaptive fast readout system for wire scanners is presented in this paper.

384

In this study, we designed and applied protein-mimicking nanoparticles (Protmin) as an intracellular nanosensor for in vivo detection of lead ions (Pb²⁺). Monodispersed gold nanoparticles (AuNPs) of 13 nm in diameter were modified using poly-adenine-tailed Pb²⁺-specific 8-17 DNAzyme to form a spherical and functional Protmin. Substrate strands modified with a fluorophore at the 5′ end and a quencher at the 3′ end were bound to DNAzyme. Pb²⁺ facilitated cleavage of DNAzyme to release the fluorophore-modified short strands to generate fluorescence. We observed rapid kinetics of the Protmin nanosensor, for which the typical assay time was 10 min. Further, we demonstrated the Protmin nanosensor could readily enter living cells and respond to Pb²⁺ in the intracellular environment. The broad of range of Protmin designs will be useful for advancing biological and medical applications.

396

DNA origami have been established as versatile templates to fabricate plasmonic nanostructures in predefined shapes and multiple dimensions. Limited to the size of DNA origami, which are approximate to 100 nm, it is hard to assemble more intricate plasmonic nanostructures in large scale. Herein, we used rectangular DNA origami as the template to anchor two 30 nm gold nanoparticles (AuNPs) which induced dimers nanostructures. Transmission electron microscopy (TEM) images showed the assembly of AuNPs with high yields. Using the linkers to organize the DNA origami templates into nanoribbons, chains of AuNPs were obtained, which was validated by the TEM images. Furthermore, we observed a significant Raman signal enhancement from molecules covalently attached to the AuNP-dimers and AuNP-chains. Our method opens up the prospects of high ordered plasmonic nanostructures with tailored optical properties.

644

The measurement of high-energy γ-rays is an important experimental method to study the giant resonance in a nucleus, γ reaction in nuclear astrophysics, and so on. The performance of a large size CsI detector for γ-rays detection is studied by comparison between the experimental measurements and GEANT4 simulation. The reliability of the simulated efficiency for low energy γ-rays is verified by comparing with the experimental data. The efficiency of the CsI detector for high energy γ-rays was obtained by the GEANT4 simulation. The simulation shows that the detection efficiency of 20 MeV γ-rays can reach 3.8%.

389

Radiological properties, such as the linear attenuation coefficient (μ, mass attenuation coefficient (μ/ρ), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and effective atomic number (Z_eff), of 304L stainless steels have been investigated with respect to photon interactions to determine the influence of current intensity at different gamma-ray energies. ¹³⁷Cs and ⁶⁰Co radioactive point sources were used to irradiate 304L stainless steels joined at 45-70 A weld currents for the transmission of the gamma rays at photon energies of 661.0, 1173.2, and 1332.5 keV. The μ, μ/ρ, HVL, TVL, MFP, and Z_eff of the steels were measured at the mentioned energies, and theoretical values for pure 304L stainless steel were calculated for comparison. The minimum differences (%) in Z_eff between pure steel and steel joined at a weld current of 60 A were observed for relevant photon energies; the minimum difference between the theoretical value for pure 304L and the experimental value for joined steel was 4.76% and that between the experimental value for pure 304L and the experimental value for joined steel was 2.60% at 1332.5 keV. Moreover, the MFPs of the joined steels were compared with that of pure 304L, and steel joined at 60 A, which had the minimum MFP, was compared with some radiation-shielding concretes in terms of MFP at the same gamma-ray energies.

565

Elastic-scattering differential cross-sections for a p-⁴He system is calculated within the framework of optical limit approximation (OLA) of the Glauber multiple scattering model (GMSM). Three different ranges for proton energy (E_lab), 19 < E_lab < 50 MeV, 100≤E_lab≤1730 MeV, and 45≤E_lab≤393 GeV are considered. It is shown that the Pauli-blocking fails to describe the data up to the proton energy, E_lab < 100 MeV. For higher proton energies a qualitative agreement is obtained. The observed elastic scattering differential cross-section is nicely reproduced in the whole range of scattering angles in the center of mass system up to Θ_c.m. < 200° for 19 <E_lab≤100 MeV when the effect of both the nucleon-nucleon (NN) phase variation parameter γ_NN and higher order momentum transfer components (λ_n, n=1 and 2) of (NN) elastic scattering amplitude are included. In the range of 200≤E_lab≤1730 MeV, introducing λ_n plays a significant role in describing the data up to the momentum transfer, q²≤1.2 (GeV/C)². Moreover, it is found that considering only the effect of phase variation parameter, γ_NN, improved the agrement in the region of minima for elastic scattering differential cross-section for 45≤E_lab≤393 GeV. The values of γ_NN and λ_n as a function of incident proton energies are presented.

593

Phase space is one of the most important parameters used to describe beam properties. Computer tomography, as a method for reconstructing phase space and measuring beam emittance, has been used in many accelerators over the past few decades. In this paper, we demonstrate a transverse phase space reconstruction study in the Shanghai soft X-ray Free Electron Laser (SXFEL) facility. First, we discuss the basic principles of phase space reconstruction and the advantage of reconstructing beam distribution in normalized phase space. Then, the phase space reconstruction results by different computer tomography methods based on the maximum entropy (MENT) algorithm and the filtered back projection (FBP) algorithm in normalized phase space are presented. The simulation results indicate that, with proper configuration of the phase advance between adjacent screens, the MENT algorithm is feasible and has good efficiency. The beam emittance and Twiss parameters are also calculated using the reconstructed phase space.

438

Sweet sorghum mutants induced by ¹²C⁶⁺-ion irradiation were planted under different soil salinity conditions to investigate the mechanisms maintaining the transport and spatial distribution of Na⁺. The functions of the synergistic responses of NHX, AKT1, and SOS1 related to Na⁺ accumulation were investigated in control (KFJT-CK) sorghum and KF1210-3 and KF1210-4 mutants. The results indicated that the NHX, AKT1, and SOS1 proteins in sweet sorghum are mainly involved in the transport, exclusion, and spatial distribution of Na⁺, respectively. In addition to physiological parameters, we also measured the expression levels of NHX, AKT1, and SOS1 genes. The experimental results indicated that 150 mM NaCl induced marked increases in the transcripts of NHX and SOS1 after 8 h and 12 h in the KF1210-3, KF1210-4, and KFJT-CK cultivars. In contrast, however, a decrease in AKT1 was observed. On the basis of our results, we propose a model in which cooperation among NHX, AKT1, and SOS1 facilitates Na⁺ homeostasis in sweet sorghum in response to an increase in salt concentration. Accordingly, study of the regulatory mechanisms in sweet sorghum generated by carbon ion irradiation is essential for the selection of salt-tolerant cultivars.

545