Ion Collection Research Articles

Behavior of ions from medium-density plasma in electric field created by plate–grid–plate geometry

The behavior of the ions from a medium-density plasma in an electric field created by the plate–grid–plate geometry was simulated with a two-dimensional one-fluid model in which electrons are assumed to be in thermal equilibrium, and the accuracy of the model was verified by comparing with other research results. The results show that the wire mesh parameters of the grid, including the wire mesh diameter and the spacing between the two wires of the grid, have an important influence on the ion extraction time and the ion collection ratio of the cathode plate. The blocking rate of the grid obtained by the theoretical simulation is almost equal to the geometrical blocking rate, and it is minimally affected by the initial ion density. These results can provide guidance for the optimization of wire mesh parameters of the grid, especially for the ion extraction and collection from a pulsed plasma.

Peak structure with a quadrupole mass filter operated in the first stability region.

In the development of commercial quadrupole mass spectrometers, there is an interest in understanding the factors that affect the transmission and peak shape of ions passing through the mass filter. These include the ion collection effects of the ion optics that lead to the presence of a peak structure. The peak structure can be observed by increasing the ion's axial kinetic energy and reducing the mass step size in a mass spectrum. The calculation of the maxima in the peak structure can be achieved by first obtaining the Mathieu characteristic parameter βy from the scan lines for each mass. The ion's secular frequency, ω0,y , along with the ion's transit time through the mass filter can then be used to calculate the location of the maxima in the peak structure. Experimentally, a peak structure has been observed for m/z 42, m/z 118 and m/z 622 in the Q1 scan mode of a triple quadrupole mass spectrometer. The peak structure has shown a dependency on the ion's axial kinetic energy, but, a mass independency with regard to the number of maxima is observed in the peak structure. In the Q3 scan mode, there is an absence of the peak structure due to the ion collection efficiency of the HED detection system. Under the right conditions, the peak structure due to ion collection effects can be observed with a quadrupole mass filter operated in the Mathieu first stability region. The presence of the peak structure has been shown to depend upon the ion collection effects at the exit of the mass filter.

Evaluation of Two-Voltage and Three-Voltage Linear Methods for Deriving Ion Recombination Correction Factors in Proton FLASH Irradiation

Ultrahigh dose-rate (FLASH) proton therapy is of great interest due to potential reduced normal tissue toxicities without compromising tumor-killing effect compared to current clinical proton practices. However, the ionization chamber response to proton beams under ultrahigh dose rates (&#x003E;40 Gy/s) has not been thoroughly investigated. In this study, four different ion chambers (PTW 34045 Advanced Markus, PPC-40, CC-04, and CC-13 from IBA Dosimetry) were irradiated with 230 MeV proton beams at 1.5, 63.7, and 127.6 Gy/s dose rates. Theoretical values of ion recombination correction factor (<inline-formula> <tex-math notation="LaTeX">${k}_{s}$ </tex-math></inline-formula>) were calculated from saturation curves using Niatel&#x2019;s model. The theoretical <inline-formula> <tex-math notation="LaTeX">${k}_{s}$ </tex-math></inline-formula> values were compared to the values using the two-voltage (2V) method from standard dosimetry protocols and the three-voltage linear (3VL) method proposed by Rossomme <i>et al.</i> Both parallel plate chambers and CC-04 demonstrated adequate ion collection efficiency at the highest dose rate. For these three chambers, there is no statistically significant difference between theoretical <inline-formula> <tex-math notation="LaTeX">${k}_{s}$ </tex-math></inline-formula> values and those calculated with 2V and 3VL methods. However, significant ion recombination correction was found in CC-13 (<inline-formula> <tex-math notation="LaTeX">${k}_{s}&gt;1.50$ </tex-math></inline-formula>) when dose rate reached 63.7 Gy/s. The assumption of insignificant initial recombination in standard dosimetry protocols also underestimated the ion recombination effect in this scenario.

Reproducible untargeted metabolomics workflow for exhaustive MS2 data acquisition of MS1 features

Unknown features in untargeted metabolomics and non-targeted analysis (NTA) are identified using fragment ions from MS/MS spectra to predict the structures of the unknown compounds. The precursor ion selected for fragmentation is commonly performed using data dependent acquisition (DDA) strategies or following statistical analysis using targeted MS/MS approaches. However, the selected precursor ions from DDA only cover a biased subset of the peaks or features found in full scan data. In addition, different statistical analysis can select different precursor ions for MS/MS analysis, which make the post-hoc validation of ions selected following a secondary analysis impossible for precursor ions selected by the original statistical method. Here we propose an automated, exhaustive, statistical model-free workflow: paired mass distance-dependent analysis (PMDDA), for reproducible untargeted mass spectrometry MS2 fragment ion collection of unknown compounds found in MS1 full scan. Our workflow first removes redundant peaks from MS1 data and then exports a list of precursor ions for pseudo-targeted MS/MS analysis on independent peaks. This workflow provides comprehensive coverage of MS2 collection on unknown compounds found in full scan analysis using a “one peak for one compound” workflow without a priori redundant peak information. We compared pseudo-spectra formation and the number of MS2 spectra linked to MS1 data using the PMDDA workflow to that obtained using CAMERA and RAMclustR algorithms. More annotated compounds, molecular networks, and unique MS/MS spectra were found using PMDDA compared with CAMERA and RAMClustR. In addition, PMDDA can generate a preferred ion list for iterative DDA to enhance coverage of compounds when instruments support such functions. Finally, compounds with signals in both positive and negative modes can be identified by the PMDDA workflow, to further reduce redundancies. The whole workflow is fully reproducible as a docker image xcmsrocker with both the original data and the data processing template.Graphical

MeCOM: A Method for Comparing Three-Dimensional Metalloenzyme Active Sites.

Since metalloenzymes are a large collection of metal ion(s) dependent enzymes, comparison analyses of metalloenzyme active sites are critical for metalloenzyme de novo design, function investigation, and inhibitor development. Here, we report a method named MeCOM for comparing metalloenzyme active sites. It is characterized by metal ion(s) centric active site recognition and three-dimensional superimposition using α-carbon or pharmacophore features. The test results revealed that for the given metalloenzymes, MeCOM could effectively recognize the active sites, extract active site features, and superimpose the active sites; it also could correctly identify similar active sites, differentiate dissimilar active sites, and evaluate the similarity degree. Moreover, MeCOM showed potential to establish new associations between structurally distinct metalloenzymes by active site comparison. MeCOM is freely available at https://mecom.ddtmlab.org.

Determination of five water-soluble anions in solid and liquid aerosols by ion chromatography with a filter membrane and condensation collection

水溶性离子是固、液气溶胶的重要组成部分,对于气溶胶的理化性质和空气质量具有重大影响,研究水溶性离子的含量对于大气环境的污染与防治具有深远意义。该研究建立了一种滤膜冷凝收集-离子色谱技术采集固体气溶胶和液体气溶胶并测定其中的5种水溶性阴离子(Cl-、F-、NO3-、NO2-、SO42-)含量的方法。首先,采用固体颗粒过滤器和冷凝收集法分别收集固体气溶胶和液体气溶胶,固体气溶胶以固体颗粒物的形式被收集在固体颗粒过滤器内,液体气溶胶以冷凝液的形式在冷阱中被收集。其次,以离子色谱法对固、液体气溶胶中的水溶性阴离子含量进行检测。在以Dionex IonPac AS11-HC-4 μm作为分析柱,流速为1 mL/min,柱温为30 ℃,淋洗液氢氧化钾(KOH)浓度在0~40 min内由1 mol/L线性增至25 mol/L,进样量100 μL的条件下,各离子在40 min内有效分离,5种阴离子在0.1~10 mg/L范围内线性关系良好(相关系数为0.9992~0.9997),检出限低(0.02~0.04 mg/L)。对样品采集条件(采样时间、采样温度和采样流量)进行了优化,结果表明,在采样时间2 h、采样温度-13 ℃、采样流量1.0 L/min的条件下,可获得较为满意的结果。在优化的条件下分别对实际样品的两类溶胶中的5种阴离子含量进行了检测,测得实际样品的液体气溶胶中5种阴离子含量分别为5.7402 μg/m3 (F-)、1.1599 μg/m3 (Cl-)、3.3233 μg/m3 (NO2-)、2.4861 μg/m3 (NO3-)和0.9745 μg/m3 (SO42-),固体气溶胶中5种阴离子含量分别为14.1037 μg/m3 (F-)、5.0398 μg/m3 (Cl-)、9.3052 μg/m3 (NO2-)、8.4528 μg/m3 (NO3-)和5.6314 μg/m3 (SO42-)。该方法可应用于实际的大气检测中,也为其他离子的采集和分析条件的摸索提供了方法。

Artificial Intelligence-Assisted Design and Virtual Diagnostic for the Initial Condition of a Storage-Ring-Based Quantum Information System

Developments in Artificial Intelligence (AI) are helping to solve complex physical problems that otherwise may be too computationally demanding to solve using traditional approaches. Universal Approximation Theorems tell us that we can model any physical system if we can approximate the system with some continuous function (i.e., compact convergence topology and algorithmically generated sets of functions, such as the convolutional neural network), whether for an arbitrary depth or arbitrary width neural network. We consider the problem of solving a set of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> coupled algebraic equations as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> becomes very large and apply machine learning (ML) to solve this problem for any value of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> . The physical problem we are focusing on is to model the equilibrium positions of ions in an ion trap. A storage ring quantum computer could contain well over tens of thousands of ions. Quickly determining the equilibrium positions will be important to minimize the time to target and observe each ion. As each ion serves as a single qubit, this is important for setting and measuring the individual qubit states. The phonon modes from a collection of ions acts as another qubit, useful for gate operations. Measuring the phonon modes, where ions are oscillating around their respective equilibrium positions also means understanding the equilibrium positions very well. Turning all of this into a virtual diagnostic allows real time prediction and comparison to ensure unique definition of each ion.

Development of dosimetric procedures for experimental ultra-high dose rate irradiation at a clinical linear accelerator

As radiotherapy using ultra-high dose rates has gained new interest, the dosimetric challenges arising at these conditions needs to be addressed. Ionization chambers suffer from a large decrease in ion collection efficiency due to ion recombination, making on-line dosimetry difficult. In this work we present experimental setups and dosimetric procedures for FLASH irradiation of cells, zebrafish embryos and small animals using a 10 MeV electron beam at a modified clinical linear accelerator, and describe the dosimetric steps required to initiate clinical trials. The dosimetric equipment used for our pre-clinical experiments consisted of radiochromic film, thermoluminescent dosimeters, a Farmer-type ionization chamber and phantom material mimicking the experimental setup for irradiation. In preparation for small animal irradiation, dose profiles and depth dose curves were measured for all collimator sizes. The average dose rates were ≥620 Gy/s, ≥640 Gy/s and ≥400 Gy/s for cells, zebrafish embryos and small animals, respectively.

Correction of the effects of carbon dioxide and hydrogen sulfide on electrostatic cell monitors measurements of radon in water

The present study shows that the presence of hydrogen sulfide and carbon dioxide in water have a negative effect on the accuracy of radon measurements in samples when an electrostatic ion collector device (RAD7) is used.CO2 concentrations between 0.65 g/l and 5.19 g/l were generated in water samples containing 222Rn activities ranging from 23.4 ± 0.9 Bq/l to 6.7 ± 0.9 Bq/l, after which the samples were measured by a RAD7 device, and the results compared to the radon activity values of the gas-free samples. The same procedure was followed for H2S concentrations from 0.125 mg/l to 3 mg/l. In both cases, a major impact was observed, the radon apparent specific activities decreasing exponentially with gas concentration. For a CO2 concentration of 1.29 g/l, the apparent specific activity underestimated the true value by 24.5%, while for a concentration of 5.19 g/l CO2 the decrease was of 57%. For H2S, the radon measured values decreased by 42.5% for concentrations as low as 0.5 mg/l, culminating in a reduction of 86.9% for 3 mg/l H2S. We are attributing these effects to 218Po neutralization processes, which reduces the electrostatic efficiency of the silicon detector system. To eliminate the interferences of these gases on RAD7 measurements, a sample preparation method was developed and tested, involving the precipitation and deposition of CO2 using Ca(OH)2, and H2S using Pb(NO3)2..The findings of the present study clearly indicate that in order to perform valid radon measurements in gas-rich waters with RAD7, the effect of the interfering gases must be considered.

Laser-wavelength dependent characteristics of protons emitted from the palladium plasma

The experimental findings regarding laser wavelength effects on the proton emission from a palladium plasma are reported. A palladium target is irradiated with fundamental, second, and third harmonics of a nanosecond pulsed laser in a broad laser fluence range (1.3–39.7 J/cm2). Time-of-flight traces of the proton pulses, measured with a planar ion collector, are used to estimate protons yield and kinetic energy. These are important parameters to consider when injecting a proton pulse into a high-energy accelerator. It was found that below the fluence of ∼10 J/cm2, the proton yield is higher for shorter wavelengths, but it does not depend on the wavelength at higher laser intensities and is ∼2 × 109 proton/pulse. For all three wavelengths, proton yield initially grows at a considerably quicker rate but slows down as fluence increases. For 355 nm and 532 nm wavelengths, the proton kinetic energies are comparable and are in the range of 280–800 eV. But the protons are 2 to 4 times less energetic in the case of 1064 nm wavelength. The disparities in proton yield and kinetic energy are attributed to the wavelength-dependent laser energy absorption in the target and plasma. The persistence of proton yield, for the successive laser pulses fired at the same target location, implies that the palladium can serve as a proton source for extended operation if ablated in suitable vacuum pressure.

Modelling and application of a new method to measure the non-thermal electron current in the edge of magnetically confined plasma

The non-thermal electrons could form considerable current in the edge plasma of tokamak and stellarator. A new method, named directional electron probe (DEP), is proposed to measure the edge non-thermal electron current in magnetically confined plasma. The DEP consists of two opposite channels whose connection line aligns with the local magnetic field line. Each channel has a hole with small radial width and enough thickness to block high energy ions due to their large Larmor radii, and at the end of the hole the collector is biased to positive voltage to repel low energy ions. In this way, the collected current of DEP is mainly contributed by electrons. A particle orbit simulation is performed based on the Boris algorithm, which demonstrates the validity and rationality of the DEP. According to the simulation, the ion collection probability is quite small if compared with the electron collection probability, consequently the collected current is mainly contributed by electrons. The collected currents of thermal electrons under Maxwell–Boltzmann distribution from both channels are almost equal, and the net current is driven by non-thermal electrons. A radial array of DEP has been successfully applied to the scrape-off layer (SOL) non-thermal electron current measurement in EAST. The amplitude and structure of the non-thermal electron current are observed during the lower hybrid wave heating phase. The experimental SOL net current is compared with the simulated net current from a rough estimation, revealing the same radial structure of SOL current and demonstrating the validity of DEP.

Adsorption of Scandium and Yttrium from Aqueous Solutions by Purolite C100Na Resin: Equilibrium and Kinetic Modeling

ABSTRACT: Adsorption of Sc from single and bi-component Sc-Y solutions by Purolite C100Na was studied experimentally and kinetic and thermodynamic characteristics are described. The extended Freundlich isotherm was found to be successful in validating the experimental results. Moreover, curve fitting the time-dependent data into different kinetics mechanisms showed a satisfactory correlation with the pseudo-second-order model. Binary system results show a decrease in Sc adsorption capacity of the absorbent in the presence of secondary ions because of competition for adsorption sites. Furthermore, thermodynamic parameters indicate similarity of reaction mechanisms for both single and binary systems, with Sc absorption adversely affected by temperature. Data from experiments on synthetic electrolytes with Y/Sc ratio of 5 found in actual mining copper leach solution were used for extracting scandium by circulating mine-leach solution through a resin column. The results demonstrate a preferential collection of Sc ions despite the fivefold concentration of Y over Sc. The elusion studies showed that the yttrium desorption peak occurs before that of Sc which, corroborates the adsorption isotherm findings. This results in a 180 mgL-1 Sc rich solution or 60:1 concentration ratio over the original copper leach solution.

Measurement of negative ion fluxes during DC reactive magnetron sputtering of Ti in Ar/O2 atmosphere using a magnetic-filtering probe

The flux of negative oxygen ions in a dc reactive magnetron discharge has been measured using a specially developed magnetic-filtering probe. The gridded probe which operates as a retarding field analyzer has a magnetic filter attached to the front entrance to suppress plasma electrons entering the device. As a result, the fluxes of unmagnetized negative ions with energies of higher than ~10 eV can arrive to an ion collector and contribute to the detected probe current. During the oxide mode of Ti–Ar/O2 magnetron sputtering discharge, the measured negative ion flux is considered to be contributed by the sputtered O− ions generated at the target surface and the plasma O− ions created in the discharge volume. However, in specific discharge conditions, the sputtered ions are likely to dominate in the measured flux signal. As a result, the yield of the sputtered O− ions and associated energy flux can be examined. The magnetic-filtering probe could potentially be employed as a real-time diagnostic tool to monitor the sputtered O− flux as well as the oxide state of the target surface during reactive magnetron sputtering processes.

Performance comparison of an extrapolation chamber in computed tomography standard beams of two laboratories

The doses received by the patients during the computed tomography (CT) exams are the highest when compared to other diagnostic radiology procedures. This fact makes it so important to keep the quality control using the correct instrument. For dosimetry in CT, a pencil type ionization chamber is usually utilized with a sensitive volume length of 10 cm. A comparison of the performance of an extrapolation chamber in two different laboratories, at the Instrument Calibration Laboratory (LCI) from Instituto de Pesquisas Energéticas e Nucleares (IPEN, Brazil) and at the National Physical Laboratory (NPL, UK) was undertaken. Two chamber characteristics were determined (zero depth and extrapolation curve), and the main recommended characterization tests were performed (stabilization time, saturation curve, polarity effect, ion collection efficiency, linearity of response, and variation of response with source-detector distance). This extrapolation chamber was calibrated using the standard system of NPL laboratory, and the energy dependence was determined. The results obtained were within the international recommendations of IEC 61674, except for the energy dependence, as already expected. This study also established a reference system for the LCI of the IPEN, using a homemade extrapolation chamber for X-ray CT beams. Using the extrapolation curves obtained in the characterization tests and the correction factors of ionic recombination, and scattering and fluorescence, the air kerma rates were obtained, as a reference system in standard laboratory computed tomography beams. The last correction factor was obtained using computer simulations by the MCNP5 code (Monte Carlo). Moreover, two pencil type ionization chambers were calibrated using the replacement method in relation to the extrapolation chamber.

A Multi-Scale Structural Engineering Strategy for High-Performance MXene Hydrogel Supercapacitor Electrode.

MXenes as an emerging two‐dimensional (2D) material have attracted tremendous interest in electrochemical energy‐storage systems such as supercapacitors. Nevertheless, 2D MXene flakes intrinsically tend to lie flat on the substrate when self‐assembling as electrodes, leading to the highly tortuous ion pathways orthogonal to the current collector and hindering ion accessibility. Herein, a facile strategy toward multi‐scale structural engineering is proposed to fabricate high‐performance MXene hydrogel supercapacitor electrodes. By unidirectional freezing of the MXene slurry followed by a designed thawing process in the sulfuric acid electrolyte, the hydrogel electrode is endowed with a three‐dimensional (3D) open macrostructure impregnated with sufficient electrolyte and H+‐intercalated microstructure, which provide abundant active sites for ion storage. Meanwhile, the ordered channels bring through‐electrode ion and electron transportation pathways that facilitate electrolyte infiltration and mass exchange between electrolyte and electrode. Furthermore, this strategy can also be extended to the fabrication of a 3D‐printed all‐MXene micro‐supercapacitor (MSC), delivering an ultrahigh areal capacitance of 2.0 F cm–2 at 1.2 mA cm–2 and retaining 1.2 F cm–2 at 60 mA cm–2 together with record‐high energy density (0.1 mWh cm–2 at 0.38 mW cm–2).

Evaluation of temporal behavior of 200 keV proton components of intense pulsed ion beam with prompt gamma- and time-of-flight spectrometry

The paper demonstrates that temporal behavior of proton components of intense pulsed ion beams accelerated to average energy of up to 200 keV with number of 1015 per shot can be reliably evaluated with use of prompt γ-spectrometry. The ion shots are dumped onto a pyrolytic h-BN plate in which a 5 mm diameter hole is provided to enable simultaneous time-of-flight measurement of the ion species with a Biased Ion Collector. The proton energy and number are determined by simultaneous control of signals from two organic scintillators shielded with lead layers of 2 and 3 cm to evaluate contributions of the nuclear reactions 10B(p, αγ)7Be and 11B(p, γ)12C via measurement of yields of prompt γ-rays with energies of 429 and 4439 keV, respectively.

Aluminum ion plasma monitored by SiC detectors from low to high laser intensity and from ns up to fs pulse duration

Thick and thin films of Al targets were irradiated in vacuum with different IR lasers at intensities between 1010 W/cm 2 and 1019 W/cm2, with pulse duration ranging between 3 ns and 45 fs. The laser-generated plasma was monitored in forward and backward directions, from thin and thick targets, by using SiC detectors, ion collectors, ion energy analyzer, optical spectrometer, Thomson parabola spectrometer and X-ray streak camera. Ion emission shows a maximum ion acceleration proportional to the laser intensity, which reaches about 1 MeV per charge state at 1016 W/cm2. Using fs laser, Al ion acceleration occurs at energies up to about 26 MeV and protons are accelerated at energies up to about 2.0 MeV.In the used experimental conditions, the maximum ion acceleration can be controlled by the laser parameters, irradiation conditions, and target geometry, such as the pulse energy, the focal position and the target thickness. Although different lasers and irradiation conditions were employed, the produced ion charges per solid angle of detection remain comparable, as it will be discussed.

Dosimetric tests of an extrapolation chamber in standard computed tomography beams

Computed tomography (CT) diagnostic exams are responsible for the highest dose values to the patients. Therefore, the radiation doses in this procedure must be accurate. For the dosimetry of CT beams, the radiation detector is usually a pencil-type ionization chamber. This type of dosimeter presents a uniform response to the incident radiation beam from all angles, which makes it suitable for such equipment since the X-ray tube executes a circular movement around the table during irradiation. However, there is no primary standard system for this kind of radiation beam yet. In order to search for a CT primary standard, an extrapolation chamber built at the Calibration Laboratory (LCI) of the Instituto de Pesquisas Energéticas e Nucleares (IPEN) was tested. An extrapolation chamber is a parallel-plate ionization chamber that allows the variation of its sensitive air volume. This chamber was used previously for low-energy radiation beams and showed results within the international recommended limits. The aim of this work is to perform some characterization tests (saturation curve, polarity effect, ion collection efficiency and linearity of response) considering the chamber depth of 1.25 mm in the radiation qualities for computed tomography beams at the LCI. The results showed to be within the international recommended limits.

Numerical investigation of ion collection by a planar probe in stationary and parallel flowing plasmas

3D hybrid particle-in-cell simulations were performed to investigate the ion current collection behavior by a thin double-sided circular planar probe in both stationary and parallel flowing plasmas with cold ions and Boltzmann electrons. Results for stationary plasma cases showed that the assumption of a constant ion density ratio at the sheath boundary to that of unperturbed plasma is inaccurate for planar probes for probe radii from 10 to 30 Debye length and probe biases from −5 to −30 times the electron temperature. The flowing plasma results showed that ion current strongly depends on the parallel flowing velocity, contrary to earlier models. The collected ion current decreases with increasing parallel velocity, reaching a minimum at around ion sound speed, then slowly recovers and even exceeds the value of the stationary case at high flow speed. The deviation of ion current due to parallel flow from stationary case could be −35% to +20% for flowing plasmas with flow speed comparable to ion sound speed. Therefore, it is important to consider the flow impact on ion collection when using planar probes in such circumstances, e.g. electric propulsion plume measurements. The mechanism for this behavior is qualitatively investigated and discussed.

Electronic structure and flotation behavior of Ag-bearing galena

The Ag-bearing galena is a typical resource of base metal sulfide accompanied by noble metal, and has always been the world's major mineral resource for silver output. In this paper, the flotation behavior of Ag-bearing galena has been investigated by using ammonium dibutyl dithiophosphate (ADD), ethyl xanthate (EX) and diethyldithiocarbamate (DDC) as collector, respectively, and unlike that galena could still remain its floatability in high alkaline pulp by DDC, the Ag-bearing galena is much favorable of flotation in low alkaline pulp at pH value of 9.5 by ADD. The electronic structures study indicates that the Ag atom in galena crystal has not changed the type of semi-conductivity, but narrows the band gap to benefit the transfer of electrons, which could enhance the electrochemical reaction activity of Ag-bearing galena. Analysis of frontier orbital also illustrates that the existence of silver could reduce the occupied molecular orbital of Ag-bearing galena, which is advantageous to the collector ion adsorption, and the interaction strength of the three collector ions suggests that ADD shows better selectivity to Ag-bearing galena. Moreover, the molecular dynamics models of the three collectors ions interacting with Ag-bearing galena {100} surface are constructed and simulated, and the results proved that ADD has the best adsorption performance to Ag-bearing galena of the three collectors, during which the S1-Pb distance and the S2-Ag distance are both below 3 Å, indicating that S1 and S2 both have strong bonding with Ag and Pb on the Ag-bearing galena surface. Thus, ADD is suggested to be an excellent collector to recover the Ag-bearing galena, especially in the low alkaline pulp at pH value of 9.5, which provide theoretical guidance and practical evidence to promote the Ag-bearing galena flotation performance in Ag-bearing lead-zinc deposits.