Mo Anode Research Articles

Conformal Conversion of Polyphosphazene@Sb2MoO6 Nanowires to N/S-Doped/Carbon-Coated SbPO4/MoOx for High-performance Lithium Storage.

Alloy-type antimony (Sb) and conversion-type molybdenum (Mo) anodes have attracted extensive attention in the application of lithium-ion batteries (LIBs) owing to their high theoretical capacity. In this study, Sb2MoO6 nanowires are prepared via a hydrothermal method and assessed their thermal behavior upon heat treatment, observing an intriguing transformation from nanowire to Sb2O3/MoOx nanosheets. To enhance structure stability, the Sb2MoO6 nanowires are successfully coated with a polyphosphazene layer (referred to as PZS@Sb2MoO6), which not only preserved the nanowires form but also yielded N/S co-doped carbon-coated SbPO4/MoOx (NS-C@SbPO4/MoOx) nanowires following annealing in an inert environment. This composite benefits from the stable PO4 3- anion that serve as a buffer against volume expansion and form a Li3PO4 matrix during cycling, both of which substantially bolster ion transport and cycle endurance. Doping with heteroatoms introduces numerous oxygen vacancies, augmenting the number of electrochemically active sites, and carbon integration considerably enhances the electronic conductivity of the electrode and alleviates the volume-change-induced electrode pulverization. Employed as anode materials in LIBs, the NS-C@SbPO4/MoOx electrode exhibits remarkable cycling performance (449.8mA h g-1at 1000mA g-1 over 700 cycles) along with superior rate capability (394.2mA h g-1 at 2000mA g-1).

Non-Ambient in-Operando X-Ray Diffraction Study of Li-Ion Batteries on Laboratory Diffractometers

A long outstanding issue when pushing the performance of batteries is the degradation during cycling. Understanding the pertinent mechanisms becomes increasingly significant to tackle them and consequently facilitate the discovery of high-performance batteries that meet the requirements for multiple applications. In operando X-ray diffraction (XRD) is a non-destructive technique which can be used to study the non-equilibrium states of a complete battery cell during cycling by essentially tracing the structure changes. In this talk, we will showcase how high-quality XRD data of Li-ion batteries can be quickly collected and analysed during charge-discharge cycles in transmission geometry on the laboratory diffractometer equipped with an X-ray tube with Ag or Mo anode and an area detector optimized for high energy X-rays. Temperature effects on the performance and life of batteries will be discussed based on the temperature-dependent XRD data collected during the charge-discharge cycling of batteries. Quantification of the structural changes from both cathode and anode materials can be done to essentially understand the structure-property relationship of a complete battery cell.

Stable Multicomponent Multiphase All Active Material Lithium-Ion Battery Anodes.

Due to their high energy density, lithium-ion batteries have been the state-of-the-art energy storage technology for many applications. Energy density can be further improved by engineering of the electrode architecture and microstructure, in addition to more common improvements via materials chemistry. All active material (AAM) electrodes consist of only the electroactive material that stores energy, and such electrodes have advantages to conventional composite processing with regards to improved mechanical stability at increased thicknesses and ion transport properties. However, the absence of binders and composite processing makes the electrode more vulnerable to electroactive materials with volume change upon cycling. Also, the electroactive material must have sufficient electronic conductivity to avoid large matrix electronic overpotentials during electrochemical cycling. TiNb2O7 (TNO) and MoO2 (MO) are electroactive materials with potential advantages as AAM electrodes due to relatively high volumetric energy density. TNO has higher energy density, and MO has much higher electronic conductivity, and thus a multicomponent blend of these materials was evaluated as an AAM anode. Herein, blends of TNO and MO as AAM anodes were investigated, where this is the first use of a multicomponent AAM anode. Electrodes that had both TNO and MO had the highest volumetric energy density, rate capability, and cycle life relative to single component TNO and MO anodes. Thus, using multicomponent materials provides a route to improve AAM electrochemical systems.

Effects of anode material on the evolution of anode plasma and characteristics of intense electron beam diode

In this paper, three kinds of materials including graphite, titanium (Ti) and molybdenum (Mo) are used as anodes to figure out the influence factors of anode material on the characteristics of the intense electron beam diode. The results show that the characteristics of diode are mainly determined by the cathode plasma motion under a 15 mm diode gap, in which the typical electron beam parameters are 280 kV, 3.5 kA. When the diode gap is reduced to 5 mm, the voltage of the electron beam reduces to about 200 kV, and its current increases to more than 8.2 kA. It is calculated that the surface temperatures of Ti and Mo anodes are higher than their melting points. The diode plasma luminescence images show that Ti and Mo anodes produce plasmas soon after the bombardment of electron beams. Ti and Mo lines are respectively found in the plasma composition of Ti and Mo anode diodes. Surface melting traces are also observed on Ti and Mo anodes by comparing the micromorphologies before and after bombardment of the electron beam. These results suggest that the time of anode plasma generation is closely related to the anode material. Compared with graphite, metal Ti and Mo anodes are more likely to produce large amounts of plasma due to their more significant temperature rise effect. According to the moment that anode plasma begins to generate, the average expansion velocities of cathode and anode plasma are estimated by fitting the improved space-charge limited flow model. This reveals that generation and motion of the anode plasma significantly affect the characteristics of intense electron beam diode.

Optimization of Image Quality in Digital Mammography with the Response of a Selenium Detector by Monte Carlo Simulation

Mammography machines must meet high requirements to ensure the quality of the generated images. On the other hand, due to the use of ionizing radiation, there is a need to minimize the dose received by patients. To optimize both of these parameters (dose and image quality), the response characteristics of image detectors and, depending on the composition of the breasts, the physical contrast of the examined structures should be considered. This study aimed to determine the optimal voltage values for a given breast thickness during imaging with the use of a selenium image detector. Analysis was carried out using the Monte Carlo simulation method with the GEANT4 code. Our results reveal that the combination of Mo anode together with Mo filtration (the system recommended in analog mammography) was the least favorable combination among those used in digital mammography machines with a selenium detector. Moreover, the use of Rh filtration instead of Mo was advantageous regardless of the thickness of the breast and resulted in a significant improvement in image quality with the same dose absorbed in the breast. The most advantageous solution was found to be an X-ray tube with a W anode. The highest values of the image quality-to-dose ratio were observed for breasts with dimensions ranging from 53 mm to 60 mm in thickness. Lower image quality was observed for breasts with smaller dimensions due to high breast glandularity, resulting in the deterioration of the physical contrast.

Analysis of the pigments in two modern Egyptian papyri using XRF technique

In this work, two modern Egyptian papyrus belonging to a private collection were analyzed using X-Ray Fluorescence technique (XRF). The papyri are genuine, made from the papyrus plant, and hand-painted. The papyri were bought in the city of Cairo, Egypt, in the ‘80s and brought to Brazil in the same period. XRF analyses were performed using a portable spectrometer ARTTAX (X-ray tube with Mo anode and a Silicon Drift Detector XFlash®, Bruker AXS Inc.). XRF measurements were carried out under the following experimental conditions: 35 kV, 600 μA, unfiltered x-ray beam, air atmosphere, acquisition time of 600 s. The elements detected in the two papyri were: Si, Al, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba and Pb. Through the XRF analysis it was possible to evaluate the pigments found in the two papyri are different from each other. In the analysis of the blue color, present in the papyrus, it was observed that the composition of this color can be a mixture of two pigments: Egyptian blue (CaCuSi₄O₁₀) and Lithopone (ZnSBaSO4). Most of the pigments on the papyri were thus recognized to be modern, their syntheses, or refinement processes not being known to ancient Egyptians.

Analysis of South America coins of the XIX and XX centuries by XRF technique

In this work, the elemental composition of 21 coins from nineteenth and twenty centuries of South America belonging to a private collection were performed using the X-Ray Fluorescence (XRF). Different coin numismatic catalogs were used as reference material. The XRF measurements were performed using ARTAX 200 system (Bruker AXS Inc., Madison, WI, USA), which consists of an X-ray tube with Mo anode and a Silicon Drift Detector. The analyses were performed with a voltage and current of 40 kV and 600 μA, respectively, and an acquisition time of 100 s. It was possible to evaluate that all twenty-one pieces were made from metallic alloys. The major elements found were Fe, Cu, Ni, Zn and Sn. Twenty coins were consistent with their cataloged version, on the other hand, only one coin showed a different chemical composition from its cataloged version. So, this result can be an indication that this coin may be a fake.

On the Generation of Intense Cs K X-Rays upon Electron Excitation of a Mo Target Heat Treated in Cs and O2 Vapors

The possibility of stable generation of intense characteristic Cs radiation upon electronic excitation of a Mo anode target heat treated in Cs and O2 vapors is demonstrated. The radiation source is a microfocus transmission type X-ray tube with a beryllium window and an S20 photocathode. A Cs-Mo-O layer is formed on the initial target in the form of a 1-µm-thick Mo film during heat treatment. The L and K spectral series are measured in an anode—cathode voltage range of 10—47 kV. A stable generation mode is observed at an electron flux power density up to 600 W/cm2. The energy of the Cs Kβ spectral line is in the region of photoabsorption peaks of the I and Xe atoms, which are widely used in the composition of contrast agents for medical diagnostics. This allows obtaining two- and three-dimensional images with the maximum contrast.

Development of X-ray phase CT with a hybrid configuration of Lau and Talbot-Lau interferometers.

X-ray phase computed tomography (CT) is used to observe the inside of light materials. In this paper, we report a new study to develop and test a laboratory assembled X-ray phase CT system that comprises an X-ray Lau interferometer, a rotating Mo anode X-ray tube, and a detector with high spatial resolution. The system has a high spatial resolution lower than 10 μm, which is evaluated by differentiating neighbouring carbon fibres in a polymer composite material. The density resolution is approximately 0.035 g/cm3, which enables to successfully distinguish the high-density polyethylene (HDPE, 0.93 g/cm3) from the ultra-low-density polyethylene (ULDPE, 0.88 g/cm3) in the sample. Moreover, the system can be switched to operate on another mode based on a Talbot-Lau interferometer that provides a wider field of view with a moderate spatial resolution (approximately 100 μm). By analyzing sample images of the biological, this study demonstrates the feasibility and advantages of using hybrid configuration of this X-ray phase CT system.

In-situ and Operando Characterization of Battery Materials using X-rays

X-ray diffraction, scattering and imaging are powerful tools for the study of battery materials [1, 2]. In this work we describe several X-ray methods, which can provide a wealth of information about new materials used in battery applications. By using X-ray diffraction (XRD) it is possible to identify the different crystallographic phases, and with the Rietveld method [3] it is possible to refine the crystallographic structures of the different materials and quantify the amount of each phase in the bulk material. It is also possible to perform in situ and operando XRD measurements of the complete battery cells. This can be done either in reflection or in transmission geometry [4-6]. In order to perform the measurements in transmission geometry, radiation with higher energy is required, e.g. Mo or Ag X-ray anodes. A newly developed Malvern Panalytical X-ray detector (GaliPIX3D) allows for shorter measurement time and/or better data quality thanks to the higher efficiency of the CdTe sensor material [7]. In addition, the short-range structure of crystalline, nano-crystalline and amorphous materials can be studied with the Pair Distribution Function method (PDF), based on a total scattering approach. Also for this technique, hard X-ray radiation (Mo or Ag anodes) is required. Imaging is also a very useful technique, enabling detailed view of the interior structure of the battery in a non-destructive way. All X-ray scattering and imaging experiments can be performed on a single X-ray instrument, such as a Malvern Panalytical Empyrean multipurpose diffractometer.[1] E. Talaie et al., Energy & Environmental Science 8, 2512-2523 (2015)[2] Z. Liu et al., Chemistry of Materials 26(8), 2513-2521 (2014).[3] H.M. Rietveld, J. Appl. Cryst. 2, 65 (1969).[4] I. Buchberger et al., Journal of The Electrochemical Society 162(14), A2737-A2746 (2015).[5] N. Sharma et al., ChemSusChem, 8, 2826-2853 (2015).[6] E. Talaie et al., Chemistry of Materials, DOI: 10.1021/acs.chemmater.6b02726 (2016).[7] G. Confalonieri et al., Powder Diffraction Journal, 30(2), Supp. 1, S65 (2015).

Validation of mammographic x-ray spectra generated using Particle and Heavy Ion Transport code System

A Monte Carlo (MC) code is a robust method to generate a mammographic x-ray spectrum because the geometry of a mammography system can be flexible and directly modeled in MC simulation. However, simulations from MC code need to be validated before it can be reliably used for specific applications. This study aimed to generate and validate the x-ray spectra of relevant anodes used in mammography and breast tomosynthesis using Particle and Heavy Ion Transport code System (PHITS). PHITS version 3.08 was used to generate the x-ray spectra of molybdenum (Mo), rhodium (Rh), and tungsten (W) anodes. The Mo anode spectrum derived using PHITS was compared with those obtained using other MC codes. The generated spectra of all anodes were compared with the literature. Parameters including spectral shape, K characteristic x-ray yield, heel effect, and half-value layer (HVL) were used for a comparative assessment. The differences in these assessment parameters conducted by PHITS and PHITSEGS5 simulations were studied. Regarding the comparative parameters, PHITSEGS5 simulation improved the accuracy of mammographic x-ray generation compared to PHITS simulation; K x-ray and bremsstrahlung yields of the Mo anode spectrum generated by PHITSEGS5 simulation were a better agreement with those generated by other MC code simulations. The PHITSEGS5 spectra overestimated K x-ray and low-energy bremsstrahlung photons in comparison with measured spectra. Subsequently, HVLs calculated from PHITSEGS5 spectra were 1.0% (Mo/Mo) and 7.0% (W/Al) lower than those derived from measured spectra. For Mo and Rh anodes, relative difference of HVLs calculated from PHITSEGS5 spectra and those obtained from literature and measurement were within the TRS 457 acceptance criteria (±0.02 mm Al). The observed difference exceeded the acceptance criteria for W anode. Regarding existed consistency in HVL between simulation and measurement, PHITSEGS5 simulation can be reliably used to generate x-ray spectra of Mo and Rh anodes. However, its accuracy should be improved for generating W anode spectrum.

Study of polylactide matrices using x-ray microtomography

Three-dimensional matrices of biodegradable polymers are promising materials for regenerative medicine. They are widely used in restoring the integrity and functions of tissues and organs using bio-artificial tissue engineering structures. We present the results of studying the structure of porous bioresorbable polymer matrices for tissue engineering using X-ray microtomography. Samples were obtained by supercritical fluid plasticization of D,L-polylactide with subsequent foaming in cylindrical molds. The tomographic method makes it possible to construct a three-dimensional voxel model of the object under study and gain apart from the estimate on the integral matrix porosity (characteristic data obtained by traditional sorption procedures) additional information about the size and spatial distribution of pores thus providing a possibility of optimization of the process parameters for production of polylactide matrices required for specific biomedical applications of architectonics, as well as forecasting the processes of their bioresorption in enzymatic media. The experiments were carried out on a laboratory microtomograph (Mo anode, the scan time of the sample is 120 min, the detector pixel size is 9 μm). Tomographic reconstruction was performed by algebraic method. The binarization procedure required for calculation of the structural characteristics of studied matrices was implemented by the method with the choice of a global threshold. Calculations of the porosity and homogeneity of the porosity distribution in the bulk, as well as estimation of the specific surface area of pores revealed the isotropy of the spatial structure of polylactide matrices.

Development of X-ray fluorescence methods by use of a Mo X-ray tube and their application in the case of biological samples

In the present work two different experimental arrangements, aiming in the X-ray fluorescence analysis of solid and liquid biological samples respectively, were developed and studied both theoretically and experimentally in combination with a Mo anode X-ray tube: The secondary target XRF (STXRF) and the Total Reflection XRF set-up (TXRF). The secondary target XRF irradiation chamber was designed and constructed in our laboratory. Careful choice of the materials combined with the tight geometry used, minimize the presence of interference peaks in the spectrum and offer high intensity of the exciting beam at the sample position. Optimum performance was ensured by means of an extended theoretical and experimental study of various parameters affecting the analytical capabilities of secondary target XRF systems, such as: The choice of secondary target material and the operational conditions of the X-ray tube. The secondary target XRF set-up was applied in the determination of the concentrations of trace elements in a pool blood serum sample. A simple preparation technique, like the freeze-drying process was employed, resulting in detection limits of 15 ng/ml for most metal trace elements and for a 6000 sec measuring time. The accuracy of the whole experimental procedure, examined by internal standardization and by analyzing the reference standard material A-13, was found to be about 4% over the whole atomic number range. For the determination of the mass absorption coefficients, necessary in the quantification step, a modified version of the emission transmission method was employed. Total Reflection X-Ray Fluorescence (TXRF) is a well-established method, mainly applied in the analysis of liquid samples, offering very low detection limits in most of the cases. Direct application of the TXRF method is not so efficient in blood serum analysis, since the high content of the organic matrix increases significantly the background due to Compton scattering. Chemical treatment of the blood serum samples and related preconcentration techniques have been suggested in literature, but they are time consuming and increase the possibility of adding contaminants in the sample. In this work, the applicability of direct TXRF analysis in blood serum samples was examined. The insertion of a Mo filter after the cut-off reflector has been found to improve significantly the peak to background ratio, especially for the elements of interest such as Cu, Zn, Se and Br. The influence of self-absorption phenomena in the quantification procedure was also investigated with respect to the internal standard used and the sample mass analyzed. Precision and accuracy in the analysis was found to be about 4% over the whole atomic number range. Detection limits were in the order of 25ng/ml for most metal trace elements and a measuring time of 3600 sec.

Extraction of plutonium-containing microcrystals from Hanford soil using a focused ion beam for single-crystal X-ray diffraction analysis

Herein, the successful use of a focused ion beam/scanning electron microscope to prepare microsamples of radioactive single crystals for X-ray diffraction analysis is reported. This technique was used to extract and analyze crystalline Pu-containing particles as small as 28 µm3from Hanford soil taken from the 216-Z-9 waste crib, which were then crystallographically characterized using single-crystal X-ray diffraction to confirm the cubic structure of PuO2. As a systematic proof of concept, the technique was first tested using UO2crystals milled into cubic shapes with approximate volumes of 4620, 1331, 125, 8 and 1 µm3, in order to empirically determine the crystal size limits for characterization by a laboratory-based diffractometer with a sealed tube Mo or Ag anode X-ray source and a charge-coupled device detector.

High-performance lateral GaN Schottky barrier diode on silicon substrate with low turn-on voltage of 0.31 V, high breakdown voltage of 2.65 kV and high-power figure-of-merit of 2.65 GW cm−2

We demonstrate high-performance AlGaN/GaN lateral Schottky barrier diodes (SBDs) with Mo anode and low turn-on voltage of 0.31 V. AlGaN/GaN SBDs with anode to cathode spacing of 6/10/15/20/25 μm achieve a breakdown voltage (BV) of 0.83/1.23/1.62/2.46/2.65 kV, yielding a power figure-of-merit (FOM) of 1.53/1.82/1.77/2.65/2.12 GW cm−2. The power FOM of 2.65 GW cm−2 and BV of 2.65 kV are the best results of AlGaN/GaN SBDs on silicon substrate. Combined with the good dynamic performance with only 10% Ron increase when switched from a −600 V stress for 10 ms, GaN SBDs verify their great promise for future power electronic applications.

Ca2CuO2Cl2, a redetermination from single-crystal X-ray diffraction data

The crystal structure of Ca2CuO2Cl2, dicalcium oxidocuprate(II) dichloride, was redetermined on the basis of single-crystal X-ray diffraction data using a laboratory Mo anode. Previous structure determinations based on single-crystal X-ray data [Grande & Müller-Buschbaum (1977). Z. Anorg. Allg. Chem. 429, 88–90], powder X-ray diffraction data [Yamada et al. (2005). Phys. Rev. B, 72, 224503–1–5] or neutron diffraction data [Argyriou et al. (1995). Phys. Rev. B, 51, 8434–8437] were confirmed. The present study allowed the refinement of anisotropic displacement parameters for all crystallographic sites, accompanied with higher accuracy and precision for bond lengths and angles. The layered title compound comprises of [CuO4] square-planar and [CaO4Cl4] square-antiprismatic coordination polyhedra, and is the undoped parent compound of a high-temperature superconducting cuprate.

Analysis of milk trace elements with a home-made portable automated total reflection x-ray fluorescence system

This paper presents a portable, high-tech, low-cost, total reflection X-ray fluorescence system. This system features a compact arrangement consisting of a 50 W X-ray mini-tube with a Mo anode and a Si-PIN detector, quartz reflectors, lucite monochromator and micrometric tables driven by step motors controlled through the Arduino programming software. A certified sample of bovine liver SRM 1577b by NIST was used for the validation of the portable automated TXRF system. The TXRF system was used in the analysis of bovine milk samples collected in the industrialized region of the city of Bauru, São Paulo. In the analysis of the bovine milk samples the following elements were detected: P, S, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Rb and Sr. The TXRF portable automated system proved to be efficient, showing that it is possible to produce X-ray fluorescence with a low-cost system using a low-power X-ray tube and a compact Si-PIN detector.

Molybdenum anode: a novel electrode for enhanced power generation in microbial fuel cells, identified via extensive screening of metal electrodes

BackgroundMetals are considered a suitable anode material for microbial fuel cells (MFCs) because of their high electrical conductivity. However, only a few types of metals have been used as anodes, and an extensive screening of metals has not yet been conducted. In this study, to develop a new metal anode for increased electricity generation in MFCs, 14 different metals (Al, Ti, Fe, Ni, Cu, Zn, Zr, Nb, Mo, Ag, In, Sn, Ta, and W) and 31 of their oxidized forms were comprehensively tested. Oxidized-metal anodes were prepared using flame oxidation, heat treatment, and electrochemical oxidation. The selected anodes were further evaluated in detail using air–cathode single-chambered MFCs.ResultsThe untreated Mo and electrochemically oxidized Mo anodes showed high averages of maximum power densities in the screening test, followed by flame-oxidized (FO) W, FO-Fe, FO-Mo, and Sn-based anodes. The untreated Mo and FO-W anodes were selected for further evaluation. X-ray analyses revealed that the surface of the Mo anode was naturally oxidized in the presence of air, forming a layer of MoO3, a known oxidation catalyst. A high maximum power density (1296 mW/m2) was achieved using the Mo anode in the MFCs, which was superior to that obtained using the FO-W anode (1036 mW/m2). The Mo anode, but not the FO-W anode, continued to produce current without detectable corrosion until the end of operation (350 days). Geobacter was abundant in both biofilms on the Mo and FO-W anodes, as analyzed by high-throughput sequencing of the 16S rRNA gene.ConclusionsThe screening test revealed that Mo, W, Fe, and Sn are useful MFC anode materials. The detailed analyses demonstrated that the Mo anode is a high-performance electrode with structural simplicity and long-term stability in MFCs. The anode can be easily prepared by merely shaping Mo materials to the desired forms. These properties would enable the large-scale preparation of the anode, required for practical MFC applications. This study also implies the potential involvement of Geobacter in the Mo and W cycles on Earth.

Deposition of metallic molybdenum thin films on 304L steel substrate by SUT-PF

Abstract The present research work aims to employ plasma focus in order to deposit molybdenum (Mo) on the 304 stainless steel substrate. The processing parameters were shot numbers as well as the distance of substrate from the anode tip. Stereo, atom force microscopy (AFM) and field emission-scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray spectroscopy (EDS) were used to study the deposited coatings. Microhardness measurements were also performed on the coatings. Results indicated that the plasma focus can be successfully applied to deposit Mo anode on the stainless steel substrate. The coatings contained discrete pores with sizes varying by processing parameters. The thickness of coatings decreased as the distance of substrate from the anode tip increased. Furthermore, the Mo content decreased in the deposited coating as the thickness of coating increased.

Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction.

Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10(7) molybdenum Kα photons.