Operando measurement of lattice deformation profiles of synchrotron radiation monochromator

This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal lattice deformation on a double-crystal monochromator at different incident powers.The nanoscale thermal lattice deformation of the monochromator first crystal was obtained by analyzing the intensity of the distorted DuMond diagrams.DuMond diagrams of the 333 diffraction index,sensitive to lattice deformation,were obtained directly using a 2D detector and an analyzer crystal orthogonal to the monochromator.With increasing incident power and power density,the maximum height of the lattice deformation increased from 3.2 to 18.5 nm,and the deformation coefficient of the maximum height increased from 1.1 to 3.2 nm/W.The maximum relative standard deviation was 4.2%,and the maximum standard deviation was 0.1 nm.Based on the measured thermal deformations,the flux saturation phenomenon and critical point for the linear operation of the monochromator were predicted with increasing incident power.This study provides a simple solution to the problem of the lower precision of synchrotron radiation monochromator characterizations compared to simulations.

Assessing high-energy x-ray and proton irradiation effects on electrical properties of P-GaN and N-GaN thin films

The effects of ionizing and displacement irradiation of high-energy x-ray and 2-MeV proton on GaN thin films were investigated and compared in this study.The electrical properties of both P-GaN and N-GaN,separated from power devices,were gauged for fundamental analysis.It was found that the electrical properties of P-GaN were improved as a consequence of the disruption of the Mg-H bond induced by high-dose x-ray irradiation,as indicated by the Hall and circular transmission line model.Specifically,under a 100-Mrad(Si)x-ray dose,the specific contact resistance pc of P-GaN decreased by 30%,and the hole carrier concentration increased significantly.Additionally,the atom displacement damage effect of a 2-MeV proton of 1×10^(13)p/cm^(2)led to a significant degradation of the electrical properties of P-GaN,while those of N-GaN remained unchanged.P-GaN was found to be more sensitive to irradiation than N-GaN thin film.The effectiveness of x-ray irradiation in enhancing the electrical properties of P-GaN thin films was demonstrated in this study.

L-shell x-ray fluorescence relative intensities for elements with 62≤Z≤83 at 18 keV and 23 keV by synchrotron radiation

The relative intensities of L-subshell x-ray fluorescence(XRF)for elements with atomic numbers 62≤Z≤83 were measured at two excitation energies,18 keV and 23 keV,using a synchrotron radiation source at a beamline of the Synchrotron Light Center for Experimental Science and Applications in the Middle East(SESAME),Jordan.The experimentally measured results of the relative intensities were compared with the calculated results using the subshell fluorescence yield and the Coster-Kronig transition probabilities recommended by Campbell and the values based on the Dirac-Hartree-Slater model by Puri.The experimental and theoretical results are in agreement.In this work,L XRF relative intensities for the elements Sm,Gd,Tb,Er,Ta,W,Re,Hg,Pb and Bi at energies of 18 keV and 23 keV were measured.

A Radiation Hardened Power Device——VDMNOSFET

A radiation hardened N channel Si power device——VDMNOSFET (Vertical Double Diffused Metal Nitride Oxide Semiconductor Field Effect Transistor) is fabricated by using a double layer (Si 3N 4 SiO 2) gate dielectric and a self aligned heavily doped shallow P + region.The effects of ionizing radiation and transient high dose rate radiation of the power VDMNOSFET are also presented.Good radiation hardening performance is obtained,compared with the conventional power VDMOSFET.For the specified 200V VDMNOSFET,the threshold voltage shifts is only -0 5V at a Gamma dose of 1Mrad(Si) with +10V gate bias;the transconductance is degraded by 10% at a Gamma dose of 1Mrad(Si);and no burnout failures occur at the transient high dose rate of 1×10 12 rad(Si)/s.It is demonstrated that the ionizing radiation tolerance and burnout susceptibilities of the power MOSFET are improved significantly by using a double layer (Si 3N 4 SiO 2) gate dielectric and a self aligned heavily doped shallow P + region.

Coherent and tunable radiation with power enhancement from surface plasmon polaritons

Surface plasmon polaritons excited by an electron beam can be transformed into coherent and tunable light radiation waves with power enhancement in the simple structure of a metal film with a dielectric medium loading. In this paper, the process of the radiation transformation of this radiation, and the dependencies of the radiation characteristics on the parameters of the structure and the electron beam are studied in detail. The radiation power enhancement is greatly influenced by the beam energy and the film thickness in the infrared to ultraviolet frequency region. Up to 122 times radiation power enhancement and 6.5% radiation frequency tuning band can be obtained by optimizing the beam energy and the parameters of the film.

Knowledge of radiation exposure associated with common trauma imaging modalities among orthopaedic surgeons,emergency medicine physicians,and general surgeons in the United States

BACKGROUND:Few contemporary studies have assessed physicians’knowledge of radiation exposure associated with common imaging studies,especially in trauma care.The purpose of this study was to assess the knowledge of physicians involved in caring for trauma patients regarding the effective radiation doses of musculoskeletal(MSK)imaging studies routinely utilized in the trauma setting.METHODS:An electronic survey was distributed to United States orthopaedic surgery,general surgery,and emergency medicine(EM)residency programs.Participants were asked to estimate the radiation dose for common imaging modalities of the pelvis,lumbar spine,and lower extremity,in terms of chest X-ray(CXR)equivalents.Physician estimates were compared to the true effective radiation doses.Additionally,participants were asked to report the frequency of discussing radiation risk with patients.RESULTS:A total of 218 physicians completed the survey;102(46.8%)were EM physicians,88(40.4%)wereorthopaedicsurgeons,and28(12.8%)weregeneralsurgeons.Physicians underestimated the effective radiation doses of nearly all imaging modalities,most notably for pelvic computed tomaography(CT)(median 50 CXR estimation vs.162 CXR actual)and lumbar CT(median 50 CXR estimation vs.638 CXR actual).There was no difference between physician specialties regarding estimation accuracy(P=0.133).Physicians who regularly discussed radiation risks with patients more accurately estimated radiation exposure(P=0.007).CONCLUSION:The knowledge among orthopaedic and general surgeons and EM physicians regarding the radiation exposure associated with common MSK trauma imaging is lacking.Further investigation with larger scale studies is warranted,and additional education in this area may improve care.

Small-angle X-ray scattering investigation of aging behavior of Al-Cu-Mg-Ag alloys using synchrotron radiation

The aging behavior of Al-Cu-Mg-Ag alloys with high Cu/Mg was studied by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) using synchrotron radiation. TEM study reveals that the major strengthening phases of the alloy after aging at 160?C for 10 h are Ω and less θ′. SAXS study shows that the scattering patterns are composed of several concentric circles at the beginning of aging process, which is replaced by the butterfly-wings scattering patterns with the increase of aging time. The butterfly-wings scattering patterns are composed of several branches. The angles between the branches are roughly equal to that between the habit planes of precipitates. The evolution of Guinier radius with aging time indicates the good coarsening resistance of the precipitates. The evolution of integrated intensity is consistent with the classical two-step precipitation process.

Polycapillary X-ray lens for the secondary focusing Beijing synchrotron radiation source

According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station, theoretical modeling of the Beijing synchrotron radiation source is developed for capillary optics. Using this theoretical modeling, the influences of the configuration curve of the polycapillary X-ray lens on transmission efficiency and working distance are analyzed. The experimental results of the transmission efficiency and working distance at the biological macromolecule station are in good agreement with the theoretical results.

Internal Structure of Cambrian Fossil Embryo Markuelia Revealed in the Light of Synchrotron Radiation X-ray Tomographic Microscopy

In the light of Synchrotron Radiation X-ray Tomographic Microscopy （SRXTM）, the internal structure of Markuelia hunanensis is revealed. In one example, vitrification and peeling show the annuli hidden under the chorion. Sectioning and 3-D reconstruction display an intact digestive tract from the inverted introvert to the terminal anus. The inverted introvert forms a rugby cavum. The following digestive tract is rope-like coiling, parallel to the body axis, about 650 μm in length, and uniform in diameter （-80 μm）. An exquisitely preserved pipe-like structure is hidden in the middle of the rope-like structure, diameter 20--40 lam, with a length of -120 μm. We interpret this pipe-like structure as the possible epidermis of the gut and its surroundings as the possible residue of musculature, similar to that in Priapulans. The two symmetrical rod-shape structures connecting the body wall and digestive tract are interpreted as the possible retractor muscles. After comparing the well preserved Left-form and Right-form Body of Markuelia, we suggest that they may represent a dimorphism. Counted directly, one sample of Markuelia hunanensis possesses 62 annulations and the other 68.

Heavy ion and X-ray irradiation alter the cytoskeleton and cytomechanics of cortical neurons

Heavy ion beams with high linear energy transfer exhibit more beneifcial physical and biological performance than conventional X-rays, thus improving the potential of this type of radiotherapy in the treatment of cancer. However, these two radiotherapy modalities both cause inevitable brain injury. The objective of this study was to evaluate the effects of heavy ion and X-ray irra-diation on the cytoskeleton and cytomechanical properties of rat cortical neurons, as well as to determine the potential mechanism of neuronal injury after irradiation. Cortical neurons from 30 new-born mice were irradiated with heavy ion beams at a single dose of 2 Gy and X-rays at a single dose of 4 Gy;subsequent evaluation of their effects were carried out at 24 hours after irradiation. An immunolfuorescence assay showed that after irradiation with both the heavy ion beam and X-rays, the number of primary neurons was signiifcantly decreased, and there was ev-idence of apoptosis. Radiation-induced neuronal injury was more apparent after X-irradiation. Under atomic force microscopy, the neuronal membrane appeared rough and neuronal rigidity had increased. These cell changes were more apparent following exposure to X-rays. Our ifnd-ings indicated that damage caused by heavy ion and X-ray irradiation resulted in the structural distortion and rearrangement of the cytoskeleton, and affected the cytomechanical properties of the cortical neurons. Moreover, this radiation injury to normal neurons was much severer after irradiation with X-rays than after heavy ion beam irradiation.

Experimental Study of the X-Ray Radiation Source at Approximately Constant Radiation Temperature

An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and

Three dimensional distribution of surfactant in microspheres revealed by synchrotron radiation X-ray microcomputed tomography

This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion solvent evaporation method using acetone and liquid paraffin system containing sucrose stearate as a surfactant. The fabricated microspheres were evaluated for encapsulation efficiency, particle size, production yield, and in vitro release characteristics. The internal structures of microspheres were characterized using synchrotron radiation X-ray microcomputed tomography(SR-μCT). The enhanced contrast made the sucrose stearate distinguished from Eudragit to have its three dimensional(3D) distribution. Results indicated that the content and concentration determined the state of sucrose stearate and had significant influences on the release kinetics of protein. The dispersity of sucrose stearate was the primary factor that controlled the structure of the microspheres and further affected the encapsulation efficiency, effective drug loading, as well as in vitro release behavior. In conclusion, the 3D internal distribution of surfactant in microspheres and its effects on protein release behaviors have been revealed for the first time. The highly resolved 3D architecture provides new evidence for the deep understanding of the microsphere formation mechanism.

Propagation characteristics of power line harmonic radiation in the ionosphere

Theoretical model and solutions on power line harmonic radiation （PLHR） propagating in the ground, air, and anisotropic homogeneous ionosphere are presented, The theoretical model is verified by the PLHR events observed by the DEMETER satellite. Some propagation characteristics of PLHR based on the model are obtained. This paper is bene- ficial to quantitatively interpret the formation mechanism of PLHR phenomenon.

High pressure x-ray diffraction techniques with synchrotron radiation

This article summarizes the developments of experimental techniques for high pressure x-ray diffraction（XRD） in diamond anvil cells（DACs） using synchrotron radiation. Basic principles and experimental methods for various diffraction geometry are described, including powder diffraction, single crystal diffraction, radial diffraction, as well as coupling with laser heating system. Resolution in d-spacing of different diffraction modes is discussed. More recent progress, such as extended application of single crystal diffraction for measurements of multigrain and electron density distribution, timeresolved diffraction with dynamic DAC and development of modulated heating techniques are briefly introduced. The current status of the high pressure beamline at BSRF（Beijing Synchrotron Radiation Facility） and some results are also presented.

Decision Technique of Solar Radiation Prediction Applying Recurrent Neural Network for Short-Term Ahead Power Output of Photovoltaic System

In recent years, introduction of a renewable energy source such as solar energy is expected. However, solar radiation is not constant and power output of photovoltaic (PV) system is influenced by weather conditions. It is difficult for getting to know accurate power output of PV system. In order to forecast the power output of PV system as accurate as possible, this paper proposes a decision technique of forecasting model for short-term-ahead power output of PV system based on solar radiation prediction. Application of Recurrent Neural Network (RNN) is shown for solar radiation prediction in this paper. The proposed method in this paper does not require complicated calculation, but mathematical model with only useful weather data. The validity of the proposed RNN is confirmed by comparing simulation results of solar radiation forecasting with that obtained from other

Radiation Protection of a Patient Undergoing an Orthopedic Procedure by Using a Mobile C-Arm X-Ray System

Modern medicine is unthinkable without X-rays. Accurate diagnosis, leading to effective treatment, is largely based on precise X-ray examinations. The creation of new, modern equipment and various medical procedures that meet the increased requirements are a priority in our time. X-ray examinations are of particular importance for the orthopedic and traumatological clinics, where they provide information about presence of a fracture in the patient’s body, about the concrete operation performed or about the effect of a suitable treatment. Along with their benefits X-rays have also a harmful effect. This requires special care to protect from this radiation. In this direction, research is constantly being done to improve the quality of radiation protection. Park MR, Lee KM and co-authors, compare the dose load obtained using C-arm and O-arm X-ray systems (which have the capability of combined 2D fluoroscopy and 3D computed tomography imaging). In their study, an orthopedic surgical procedure using C-arm and O-arm systems in 2D fluoroscopy modes was simulated. The radiation doses to susceptible organs of the operators were investigated. He results obtained show that the O-arm system delivered higher doses to the sensitive organs of the operator in all configurations [1]. The article of Stephen Balte briefly reviews the available technologies for measuring or estimation of patient skin dose in the interventional fluoroscopic environment, created by various X-ray equipment including C-arm systems. Given that many patients require multiple procedures, this documentation also aids in the planning of follow up visits [2]. Chong Hing Wong, Yoshihisa Kotani and co-authors evaluate the radiation exposures (RE) to the patient and surgeon during minimally invasive lumbar spine surgery with instrumentation using C-arm image intensifier or O-arm intraoperative CT. The results they get are in favor of the O-arm system [3]. The article “Virtual fluoroscopy for intraoperative C-arm positioning and radiation dose reduction” discusses positioning of an intraoperative C-arm system to achieve clear visualization of a particular anatomical feature by a system for virtual fluoroscopy (called FluoroSim) that could dramatically reduce time and received dose during the procedures. FluoroSim was found to reduce the radiation exposure required for C-arm positioning without reducing positioning time or accuracy, providing a potentially valuable tool to assist surgeons [4]. In our study, we performed practical measurements to show how the patient can be treated by applying most effective radiation protection when using a mobile C-arm X-ray system. For the study, we used exposure upon a phantom placed on the patient’s table. For an X-ray shielding, we used a protective apron with a lead equivalent of 1 mm, placed in two layers on the phantom. In each subsequent series of exposures, the protective apron was placed on the phantom, in a different position relative to the X-ray beam. The general conclusion of our study is that in order to obtain maximum protection from scattered radiation when using C-arm X-ray systems, the patient must be protected by a shielding with a suitable lead equivalent for the procedure performed which must be placed between patient’s body and X-ray tube, perpendicular to the X-ray beam pointed toward the region of interest.

Time-resolved ultra-small-angle X-ray scattering beamline(BL10U1)at SSRF

The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results.

The hard X-ray nanoprobe beamline at the SSRF

The hard X-ray nanoprobe beamline BL13U is a phase-Ⅱ beamline project at the Shanghai Synchrotron Radiation Facility.The beamline aims to enable comprehensive experiments at high spatial resolutions ranging from 50 to 10 nm. The X-ray energy range of the beamline, 5–25 keV, can detect most elements in the periodic table. Two operating modes were designed to accommodate the experimental requirements of high-energy resolution or high photon flux, respectively. X-ray nanofluorescence, nanodiffraction, and coherent diffraction imaging are developed as the main experimental techniques for BL13U. This paper describes the beamline optics, end station configurations, experimental methods under development, and preliminary test results. This comprehensive overview aims to provide a clear understanding of the beamline capabilities and potential applications.

High-precision X-ray polarimeter based on channel-cut crystals

We report on using synthetic silicon for a high-precision X-ray polarimeter comprising a polarizer and an analyzer,each based on a monolithic channel-cut crystal used at multiple Brewster reflections with a Bragg angle very close to 45°.Experiments were performed at the BL09B bending magnet beamline of the Shanghai Synchrotron Radiation Facility using a Si(800)crystal at an X-ray energy of 12.914 keV.A polarization purity of 8.4×10^(-9)was measured.This result is encouraging,as the measured polarization purity is the best-reported value for the bending magnet source.Notably,this is the firstly systematic study on the hard X-ray polarimeter in China,which is crucial for exploring new physics,such as verifying vacuum birefringence.

High-precision X-ray characterization for basic materials in modern high-end integrated circuit

Semiconductor materials exemplify humanity's unwavering pursuit of enhanced performance,efficiency,and functionality in electronic devices.From its early iterations to the advanced variants of today,this field has undergone an extraordinary evolution.As the reliability requirements of integrated circuits continue to increase,the industry is placing greater emphasis on the crystal qualities.Consequently,conducting a range of characterization tests on the crystals has become necessary.This paper will examine the correlation between crystal quality,device performance,and production yield,emphasizing the significance of crystal characterization tests and the important role of high-precision synchrotron radiation X-ray topography characterization in semiconductor analysis.Finally,we will cover the specific applications of synchrotron radiation characterization in the development of semiconductor materials.