Vol.30,

The mass energy-absorption coefficient (μ_en/ρ), effective atomic number (ZPEAeff), and electron density (NPEAeff) of some biomolecules with potential application in radiation dosimetry were calculated for their photon energy absorption (PEA) in the energy region of 1 keV to 20 MeV. It was noticed that the values of μ_en/ρ, ZPEAeff, and NPEAeff vary with the energy and composition of the biomolecules. The results for ZPEAeff were compared with effective atomic numbers (ZPIeff) owing to the photon interaction (PI). Significant differences were noted between ZPEAeff and ZPIeff in the energy region of 10 to 150 keV for all of the biomolecules involved. A maximum difference of 45.36% was observed at 50 keV for creatinine hydrochloride. Moreover, the studied attenuation parameters were found to be sharply affected at the K-absorption edge of relatively high-Z elements present in the biomolecules.

551

The mass attenuation coefficients (μ/ρ) of a natural material, i.e. olive peat, were measured at photon energies of 0.059, 0.356, 0.662, 1.17, and 1.332 MeV and compared with those of concrete and Pb. The experimental samples were irradiated with ²¹⁴Am, ¹³³Ba, ¹³⁷Cs, and ⁶⁰Co point sources using a transmission arrangement. The olive peat samples were obtained from different areas in Jordan, namely Mafraq (sample M), Kerak (sample K), Ajloun (sample A), and Irbid (sample I), and photon energies were measured using a NaI(Tl) scintillation detector with an energy resolution of 7.6% at 662 keV. The differences in the µ/ρ of olive peat samples and the calculated µ/ρ of concrete were consistently within 0.7%. This finding indicates that olive peat can be used in radiation applications in the field of medical physics. Finally, the half-value layer (HVL) of the experimental samples was measured, and results were compared with those of concrete and Pb. Pb and concrete exhibited minimal X_1/2 values due to their high density, and the HVL of olive peat revealed lower shielding effectiveness than that of concrete.

572

Sodium borosilicate glasses are candidate materials for high-level radioactive waste (HLW) vitrification; therefore, understanding the irradiation effects in model borosilicate glass is crucial. Effects of electronic energy deposition and nuclear energy deposition induced by the impact of heavy ions on the hardness and Young's modulus of sodium borosilicate glass were investigated. The work concentrates on sodium borosilicate glasses, henceforth termed NBS1 (60.0% SiO₂, 15.0% B₂O₃ and 25.0% Na₂O in mol %). The NBS1 glasses were irradiated by P, Kr and Xe ions with 0.3 MeV, 4 MeV and 5 MeV respectively. The hardness and Young's modulus of ion-irradiated NBS1 glasses were measured by nanoindentation tests. The relationships between the evolution of the hardness, the change in the Young’s modulus of the NBS1 glasses, and the energy deposition were investigated. With the increase of the nuclear energy deposition, both the hardness and Young's modulus of NBS1 glasses dropped exponentially and then saturated. Regardless of the ion species, the nuclear energy depositions required for the saturation of hardness and Young's modulus were apparent at approximately 1.2×10²⁰ keV/cm³ and 1.8×10²⁰ keV/cm³, respectively. The dose dependency of the hardness and Young's modulus of NBS1 glasses was consistent with previous studies by Peuget et al. Moreover, the electronic energy loss is less than 4 keV/nm, and the electronic energy deposition is less than 3.0×10²² keV/cm³ in this work. Therefore, the evolution of hardness and Young's modulus could have been primarily induced by nuclear energy deposition.

809

615

Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers (15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction, and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au (111) orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200 °C in a vacuum was performed on the ﬁlms deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the ﬁlms. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 °C and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175 °C, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.

803

In this study, the gamma radiation shielding features of several environmentally-friendly materials were investigated. For this purpose, several attenuation parameters, such as the mass attenuation coefficient (μ/ρ), radiation protection efficiency (RPE), and effective atomic number (Z_eff) were determined experimentally and compared with numerical data obtained using WinXCOM software. In the measurements, the emitted gamma photons were counted by a gamma spectrometer equipped with an HPGe detector using ²²Na, ⁵⁴Mn, ⁵⁷Co, ⁶⁰Co, ¹³³Ba, and ¹³⁷Cs radioactive point sources in the energy region of 81–1333 keV. The obtained results indicate that the μ/ρ and RPE values of the samples decrease with increasing photon energy. The experimental values are in good agreement with those obtained using WinXCOM software. The RPE and Z_eff results show that, among the studied materials, the NaY_0.77Yb_0.20Er_0.03F₄ sample has the best gamma radiation shielding effectiveness.

979

A shard of Chinese under-glaze copper-red porcelain from the Yuan dynasty (AD 1271-1368) made in the Jingdezhen kiln was measured by synchrotron radiation induced X-ray fluorescence (XRF) mapping and X-ray absorption near-edge spectroscopy (XANES) to investigate the influence of copper element distribution and speciation on the color of porcelain. In black-colored region, copper accumulates at the interface between the body and glaze layers with metallic copper particles as the main speciation. In contrast, Cu is irregularly distributed in the red-colored region with multi-valence speciation. The differences in Cu distribution and speciation in black- and red-colored regions indicate that they are the main factors influencing the different colors of copper-red under-glaze porcelain.

577

The objective of this work is to analyze the transient effects of ⁶⁰Co gamma rays in the CMOS image sensor (CIS) using the Monte Carlo method, based on Geant4. The track, energy spectrum, and angle of produced electrons when gamma rays traversed an silicon or silicon dioxide cube were calculated. A simplified model of a 500×500 CIS array was established, and the transient effects of gamma rays in the CIS were simulated. The raw images were captured when the CIS was irradiated by gamma rays. The experimental results were compared with the simulation results. The characteristics of the typical events induced by transient effects were analyzed.

587

Shanghai high-repetition-rate XFEL and extreme light facility (SHINE), the first hard XFEL based on a superconducting accelerated structure in China, is now under development at the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. In this paper, power losses caused by trapped longitudinal high-order modes (HOM), steady-state loss, and transient loss generated by untrapped HOMs in the 1.3-GHz SHINE cryomodule are investigated and calculated. The heat load generated by resistive wall wakefields is considered as well. Results are presented for power losses of every element in the 1.3-GHz cryomodule, caused by HOM excitation in the acceleration RF system of the continuous wave linac of SHINE.

663

A C-band accelerator structure was used to accelerate electrons at the Shanghai Soft X-ray Free-Electron Laser Test Facility (SXFEL-TF) in Shanghai Institute of Applied Physics (SINAP). The microwave system of this accelerator structure used a 110 MW pulse modulator and a klystron (PV-5050) to provide the power supply. A pulse transformer is a crucial device in a modulator klystron system, and plays significant roles in voltage level transformation, matching impedances, and polarity inversion. This study presents the optimization of a high-voltage pulse transformer. The design considerations of reducing flattop ringing and flattop droop, and shortening leading edge are provided. The model simulation, mechanical design, and the relevant experimental results are also presented.

830

Longitudinal injection is a promising on-axis injection scheme for diffraction-limited storage rings (DLSR). In the latest version of the Hefei Advanced Light Source (HALS), both the dynamic aperture and momentum aperture have been optimized. A longitudinal injection scheme was investigated on the HALS using a double-frequency radio frequency system. To evaluate the injection performance, various errors were considered. A series of tracking simulations were conducted, and the injection efficiency was obtained under different error levels.

710

CR-RC^m filters are widely used in nuclear energy spectrum measurement systems. The choice of parameters of a CR-RC^m digital filter directly affects its performance in terms of energy resolution and pulse count rate in digital nuclear spectrometer systems. A numerical recursive model of a CR differential circuit and RC integration circuit is derived, which shows that the shaping result of CR-RC^m is determined by the adjustment parameter (k, it determines the shaping time of the shaper) and the integral number (m). Furthermore, the amplitude-frequency response of CR-RC^m is analyzed, which shows that it is a bandpass filter; the larger the shaping parameters (k and m), the narrower is the frequency band. CR-RC^m digital Gaussian shaping is performed on the actual sampled nuclear pulse signal under different shaping parameters. The energy spectrum of ¹³⁷Cs is measured based on the LaBr₃(Ce) detector under different parameters. The results show that the larger the shaping parameters (m and k), the closer the shaping result is to Gaussian shape, the wider is the shaped pulse, the higher is the energy resolution, and the lower is the pulse count rate. For the same batch of pulse signals, the energy resolution is increased from 3.8% to 3.5%, and the full energy peak area is reduced from 7815 to 6503. Thus, the optimal shaping parameters are m=3 and k=0.95. These research results can provide a design reference for the development of digital nuclear spectrometer measurement systems.

845

The arrangement of DNA-based nanostructures into the desired large-scale periodic pattern with the highest possible accuracy and control is essential for the DNA application in functional biomaterials; however, formation of a DNA nanostructure pattern without utilizing the molecular interactions in nanotechnology field remains difficult. In this article, we use the optimal concentration and adsorption time of origami to induce DNA origami in the form of a large-scale 2D pattern on mica without changing the origami itself. DNA origami structures can form a pattern by close-packing of symmetric and electrostatic interactions between ions, which was confirmed by the atomic force microscopy images. Furthermore, we identified favorable conditions for the concentration of DNA origami and optimal adsorption time, which can enable pattern formation with DNA origami. This work provides an insight to understand the adsorption of DNA on mica and guides researches on regular DNA nanostructure pattern, which can serve as templates for pattern formation of proteins or other biomolecules.

845

A measurement of the ²³⁵U prompt fission neutron spectrum (PFNS) by the recoil proton method was performed at the Institute of Nuclear Physics and Chemistry (INPC), China. Details of the method, which include the calculation and validation of the response matrix, are presented. The PFNS for ²³⁵U in the energy range 1 − 12 MeV, induced by thermal neutrons, was obtained. The measured spectrum in the low-energy region was in good agreement with previous work and the ENDF/B-VII library, except for minor differences. In the high-energy region, however, the relative height of the measured spectrum was greater, and an analysis of the experiment indicated uncertainties of 13% at 10 MeV and 24% at 12 MeV. Experimental results showed that the recoil proton method could be used to measure prompt fission neutron spectra. Some directions for future work are included.

597