Thermal Spike Research Articles

JWST sighting of decameter main-belt asteroids and view on meteorite sources.

Asteroid discoveries are essential for planetary-defense efforts aiming to prevent impacts with Earth1, including the more frequent2 megaton explosions from decameter impactors3-6. While large asteroids (≥100 km) have remained in the main belt since their formation7, small asteroids are commonly transported to the near-Earth object (NEO) population8,9. However, due to the lack of direct observational constraints, their size-frequency distribution -which informs our understanding of the NEOs and the delivery of meteorite samples to Earth-varies significantly among models10-14. Here, we report 138 detections of the smallest asteroids (⪆10 m) ever observed in the main belt, which were enabled by JWST's infrared capabilities covering the asteroids' emission peaks15 and synthetic tracking techniques16-18. Despite small orbital arcs, we constrain the objects' distances and phase angles using known asteroids as proxies, allowing us to derive sizes via radiometric techniques. Their size-frequency distribution exhibits a break at ~100 m (debiased cumulative slopes of q=-2.66±0.60 and -0.97±0.14 for diameters smaller and larger than ~100 m, respectively), suggestive of a population driven by collisional cascade. These asteroids were sampled from multiple asteroid families -most likely Nysa, Polana and Massalia- according to the geometry of pointings considered here. Through additional long-stare infrared observations, JWST is poised to serendipitously detect thousands of decameter-scale asteroids across the sky, probing individual asteroid families19 and the source regions of meteorites13,14 "in-situ".

Molecular dynamic simulations of displacement cascades in Molybdenum and Molybdenum-Rhenium alloys

Molybdenum-Rhenium (Mo-Re) alloys are considered core materials for advanced nuclear reactor components due to their excellent mechanical properties, machinability, and resistance to irradiation damage. However, irradiation-induced embrittlement and phase precipitation at high temperatures, along with transmutation nuclides, have hindered their broader application. To address this, we developed a Mo-Re interatomic potential using the Finnis-Sinclair formalism, facilitating molecular dynamics simulations to study primary irradiation damage. Systemically primary irradiation damage simulations for Mo and Mo-Re alloys have been performed. It’s found that there were more Frenkel-pair defects produced during the stage of thermal spike in Mo-Re alloys but fewer defects survived at the end of the cascade compared to Mo. In addition, the number of large-size interstitial clusters and dislocation loops was higher in Mo-Re alloys than in pure Mo with the same PKA energy. This is mainly attributed to the fact that Mo-Re alloys have lower thermal conductivity, while the binding energies of interstitial clusters and dislocation loops with sizes less than 100 in Mo-Re alloys are comparable to those of pure Mo, resulting in higher defect composites and larger defect sizes in Mo-Re alloys. These findings provide valuable insights into the primary damage mechanisms in Mo-Re alloys under irradiation, offering a foundation for developing kinetic models to simulate radiation-induced microstructural evolution.

Non-Fourier thermal spike effect on nanocrystalline Cu phase engineering

The thermal spike effect dominates rapid heating and quenching at the nanoscale in ion beam assisted materials surface phase engineering. This phenomenon often leads to the formation of metastable nanocrystalline phases in the resulting micro-/nanostructures. However, such a non-equilibrium process cannot be accurately described by the conventional Fourier thermal spike model. In this study, a non-Fourier model is proposed to elucidate the dynamics of heat diffusion in sub-keV Cu ion beam sputter deposition. The effects of beam density and energy on the non-equilibrium thermal and stress fields are quantitatively investigated. The influence of high stress field on nanocrystalline Cu phase content is also studied. It is found that the energetic Cu ion beams produce a rapidly oscillating stress field with a maximum of ∼ 10 GPa within 50 ps, which significantly constrains the growth of nanocrystalline Cu phase at a threshold of ∼ 4 GPa. This understanding provides new insights into the formation of metastable nanocrystalline phases in the fabrication and modification of surface micro-/nanostructures using ion beam assisted techniques.

Effects of chemical short-range order on displacement cascade in medium-entropy CrCoNi alloys

Chemical short-range order (CSRO) is an important structure in high/medium entropy alloys (H/MEAs), which has a significant influence on the mechanical properties of irradiated materials. In this work, molecular dynamics (MD) simulations are performed to investigate the effects of CSRO on the point defect evolution during displacement cascade in medium-entropy CrCoNi alloys. To validate the influence of CSRO on point defects, multi-displacement cascades were initially conducted on the alloy. The results indicate that the CSRO structure can notably diminish dislocation and defect densities. Then, the influence of the CSRO structure on point defects under single displacement cascade was discussed. Both the peak number of point defects and the number of surviving point defects decrease with the increasing degree of CSRO during the single displacement cascade, indicating that the CSRO enhances the irradiation-resistance of irradiated materials. The Ni-rich region in CSRO can inhibit the formation of point defects due to its higher formation energy barrier. While the Co-Cr region in CSRO was found to promote the migration of point defects that can facilitate their recombination due to the lower migration energy. The current work provides new insights into understanding the evolution of irradiation-induced defects and mechanical properties of irradiated M/HEAs.

Unveiling the interactions between preexisting dislocations and displacement cascades in the refractory high-entropy alloy WTaCrV

Refractory high-entropy alloys (RHEAs) represented by WTaCrV are excellent candidates for future nuclear reactor structures. Both the preexisting edge dislocations (EDs) and screw dislocations (SDs) can significantly impact the irradiation performance of RHEAs. To explore the influence of preexisting dislocations on the generation and evolution of irradiation point defects in the RHEA WTaCrV, the interactions between preexisting dislocations (including EDs and SDs) and displacement cascades are studied by molecular dynamics simulations in this work. In addition, the results of the RHEA WTaCrV without preexisting dislocations and of pure W with preexisting dislocations are included for comparison. It is found that the presence of preexisting dislocations leads to a significant increase in the number of remained point defects after the cascades. However, the absorption of vacancies by dislocation cores in the RHEA WTaCrV is more significant than that in the pure W. Therefore, preexisting dislocations can reduce the possibility of void formation and act as sites for recombination of vacancies and interstitials in the subsequent long-term evolution. For the preexisting EDs in the RHEA WTaCrV, the local pinning of EDs, the attraction of vacancies, and the severe lattice distortion jointly cause the bowing out of EDs, which is conductive to accommodate vacancies. For the preexisting SDs, the abundant cross kinks tend to bind vacancies or interstitials, promoting the motion of SDs as well as the annihilation of point defects. In this sense, the preexisting dislocations in the RHEA WTaCrV can significantly enhance the irradiation resistance. The results of this research can provide design guidance for regulating the anti-irradiation performance of RHEAs.

Mechanical response of carbon ion implanted ferrite via atomic simulations

Ion implantation plays a nontrivial role in improving the mechanical properties of materials. Unfortunately, the atomic-scale understanding and awareness of the improvement mechanisms remain insufficiently clear and accurate. This paper investigates the nanostructural evolution of carbon ion implanted ferrite and the mechanical response under uniaxial tension leveraging molecular dynamics (MD) simulation, providing direct atomic-scale evidence of alloy strengthening. Regarding nanostructural evolution, grain boundary migration induced by carbon ion implantation becomes significant with increasing doses. However, point defects and amorphous structures caused by collision cascades tend to saturate gradually with increasing implantation doses. Uniaxial tensile test results indicate that the strength of all ion-implanted samples is appreciably enhanced compared to non-implanted samples, especially with an implantation dose of 6.23 × 1013 ions/cm2, where the strength increases by 39%. The underlying strengthening mechanism is that defects, amorphous structures, and lattice distortions induced by ion implantation collectively act as formidable barriers to dislocation motion during plastic deformation, strongly governing dislocation propagation and multiplication. More importantly, the interaction between carbon atoms from ion implantation and dislocations renders the formation of Cottrell atmospheres, which further enhances solid solution strengthening by pinning dislocations. These results advancing the fundamental understanding of nanostructural evolution and strengthening mechanism under ion implantation suggest a mechanistic strategy for augmenting alloy strength.

Fast prediction of irradiation-induced cascade defects using denoising diffusion probabilistic model

Irradiation-induced cascade collisions produce numerous point defects within materials, which can severely deteriorate their thermo-mechanical properties and overall performance. We propose a computational scheme that combines molecular dynamic (MD) simulations with a denoising diffusion probabilistic model (DDPM) to rapidly and accurately predict the spatial coordinates of point defects at any given primary knock atom (PKA) energy, ranging from 0 to 100.0 keV. Importantly, this capability extends to PKA energies that are exclusive from the training data set, demonstrating the robustness and generalizability of the model. The proposed scheme has been thoroughly validated by several designed indicators, including the Fréchet inception distance, the number of point defects, the distance from vacancies and self-interstitial atoms (SIAs) to their respective centroids, the inter-centroid distance between the vacancies and SIAs, the probability density of clustered defect sizes, and the sub-cascade number. Compared to MD simulations, the DDPM can generate point defects at a specific PKA energy at least ten thousand times faster. By offering a rapid and reliable means to model defect distributions across various energy levels, the proposed scheme benefits the comprehension of the cascade process and provides a valuable database for both experimental investigations and large-scale simulations.

Rate theory model of irradiation effects in UO2: Influence of electronic energy losses

To investigate the effect of electronic energy losses on nuclear damage in UO2, we use a simple Rate Theory (RT) model, based on the time evolution of single point defects, governed by their absorption at the surface of TEM lamellae, and by interstitial-type dislocation loops nucleation, solely characterized by their number and average size. We first parametrize the model by fitting six different experimental datasets at various temperatures, ion type and energy (0.39 MeV Xe and 4 MeV Au ion irradiations at 93, 298 and 873 K) where defect evolution in UO2 is dominated by displacement damage caused by nuclear energy losses. The model suggests that dislocation evolution kinetics is driven by monomers diffusion at 873 K. At lower temperature (93 and 298 K) monomer diffusion has little impact and the evolution is governed by the nucleation of loops within the collision cascade. Analysis of four additional experimental datasets at 93 and 298 K where electronic energy losses are strong (single 6 MeV Si and dual simultaneous Xe & Si ion irradiations) required modification of monomer's diffusion coefficients. In the case of single Si ion irradiation, evolution is temperature independent and the enhanced diffusion due to electronic excitations and ionizations are best captured by adding athermal component to the monomer diffusion coefficients. In case of the dual Xe & Si ions irradiation, electronic excitation caused by Si ions impacts the defects pre-generated by Xe ions and enhances defect diffusion by at local heating induced by the thermal spike of Si ions. This effect is best captured by artificially raising the irradiation temperature.

Radiation protection of W–Al composite films/coatings for aviation using genetic algorithms

This study evaluated electron shielding capabilities of various materials using Geant4 Monte Carlo software. By analyzing materials with different atomic numbers, we designed and tested composite films and coatings for radiation protection. Under 1.2 MeV electron irradiation, these materials reduced the dose deposited in electronic components by over 70 %. The fabricated composite films (W–Al) reduced the actual total dose by 100 % with a 30.67 % mass increase, closely matching the simulation result of 75.36 %. The composite coatings (W–Al) reduced the dose by 89.2 % with a 33 % mass increase, matching the simulation result of 70 %. Cascade collision simulations revealed that higher PKA energies lead to longer times to reach the thermal peak, more peak defects, and more stable defect pairs. This is due to the displacement threshold energy of the atoms in aluminum and tungsten. These results demonstrate the effectiveness of our composite films and coatings in enhancing electron shielding performance and validate our design methods.

Non-linear effects in α-Ga2O3 radiation phenomena

The rhombohedral phase of gallium oxide (α-Ga2O3) is of interest because of its highest bandgap among the rest of the Ga2O3 polymorphs, making it particularly attractive in applications. However, even though the ion beam processing is routinely used in device technology, the understanding of radiation phenomena in α-Ga2O3 is not mature. Here, we study non-linear effects for radiation disorder formation in α-Ga2O3 by varying both the defect generation rate and the density of collision cascades, enabled by comparing monoatomic and cluster ion implants, also applying systematic variations of ion fluxes. In particular, we show that the collision cascade density governs the surface amorphization rates, also affected by the ion flux variations. These trends are explained in terms of the non-linear in-cascade and inter-cascade defect interactions occurring during ballistic and dynamic defect annealing stages. As such, these data reveal new physics of the radiation phenomena in α-Ga2O3 and may be applicable for more predictive ion beam processing of α-Ga2O3-based devices.

Microstructure evolution of CdZnTe crystals irradiated by heavy ions

Consideration of irradiation effects is important for in-orbit operation and radiation protection in aerospace applications. The configuration of irradiation defects and their impact on deteriorating the carrier transport properties of CZT crystals need to be clarified. In this study, the microdefect evolution mechanism of CdZnTe (CZT) crystals under 10 MeV Chlorine (Cl) ion irradiation at flux of 1×1010∼1×1012 n·cm-2 are investigated. The stacking faults first appear in the CZT crystal at 4.5×10-4 displacement per atom (dpa), which are categorized into slip-type, gap-type and vacancy-type. In order to hinder the further expansion of stacking fault, S-shaped stacking fault dipole appears. When the dpa reaches 4.5×10-2, the local phase transition occurs in the damage zone to form CuPt-A ordered phase with ZnTe/CdTe periodic arrangement because the fluctuation in local composition and strain caused by cascade collisions. The deterioration of electric field distribution and charge collection caused by irradiation damage layer leads to the decrease of γ-ray detection ability. The energy resolution (ER) of the CZT detector for γ-ray can be maintained at 30.6% when the ion flux accumulates to 1×1012 n·cm-2, revealing high irradiation hardness. Consequently, these findings provide a theoretical basis for the radiation damage recovery of CZT detectors, further demonstrating that CZT crystals are the most competitive new generation of room-temperature nuclear radiation detection materials, and can provide radiation protection strategies for similar compound semiconductor materials.

Parent-Specific Transgenerational Immune Priming Enhances Offspring Defense-Unless Heat Stress Negates It All.

Transgenerational immune priming (TGIP) adjusts offspring's immune responses based on parental immunological experiences. It is predicted to be adaptive when parent-offspring environmental conditions match, while mismatches negate those advantages, rendering TGIP potentially costly. We tested these cost-benefit dynamics in the pipefish Syngnathus typhle (Syngnathidae). Because of their unique male pregnancy, egg production and rearing occur in different sexes, providing both parents multiple avenues for TGIP. Parental bacteria exposure in our pipefish was simulated through vaccinations with heat-killed Vibrio aestuarianus before mating the fish to each other or to controls. The resulting offspring were exposed to V. aestuarianus in control or heat stress environments, after which transcriptome and microbiome compositions were investigated. Transcriptomic TGIP effects were only observed in Vibrio-exposed offspring at control temperatures, arguing for low costs of TGIP in non-matching microbiota environments. Transcriptomic phenotypes elicited by maternal and paternal TGIP had limited overlap and were not additive. Parentally induced transcriptomic responses were associated with immune functions, and specifically, the paternal response to the innate immune branch, possibly hinting at trained immunity. TGIP of both parents reduced the relative abundance of the experimental Vibrio in exposed offspring, showcasing its ecological benefits. Despite TGIP's significance in matching biotic environments, no TGIP-associated phenotypes were observed for heat-treated offspring, illustrating its limitations. Heat spikes caused by climate change thus threaten TGIP benefits, potentially increasing susceptibility to emerging marine diseases. We demonstrate the urgent need to understand how animals cope with climate-induced changes in microbial assemblages to assess their vulnerability in light of climate change.

Thermal transport recovery in irradiated SiC mediated by nano-layered stacking faults

We investigate phonon thermal transport and resistance to ion irradiation in nanostructured 3C-SiC using molecular dynamics (MD) simulations. Two-dimensional planar defects in the form of stacking faults (SFs) spaced within nanometer-scale vicinity from each other promote healing of both: radiation-induced point defects (PDs) and thermal conductivity (k) under 10 keV Si ion irradiation number of displacements per atoms (DPA= 0.0016 – 0.034). With the rise of DPA below the onset of amorphization, the decay in k due to PDs and SFs is found to be less rapid than that due to the presence of only PDs. Observed relative recovery of heat conductivity is due to enhanced recombination of Frenkel pair PDs spatially confined between neighboring SFs, as confirmed by collision cascade MD simulations. Calculations from the Boltzmann transport equation combined with the Klemens model are consistent with findings from MD simulations. The interplay between enhanced PD recombination and thermal transport recovery is observed for different types of SFs. Obtained results pave the way to guide the design of nano-engineered nuclear ceramics with simultaneously enhanced radiation tolerance and heat conductive properties.

Molecular dynamics simulation of particle radiation damage processes in ZnO crystals

Abstract The cascade collision process in ZnO crystal caused by Primary Knocked Atom (PKA) under different incident conditions has been simulated by the Molecular Dynamics (MD) method. Simulation results show that the incident depth is smaller than 20 atomic layers for PKAs with initial kinetic energy less than 2 keV, and more than 30 atomic layers for PKAs with energy larger than 5 keV. For PKAs with lower energy, the defects are mainly distributed near the incident trajectory, and the distribution range of defects becomes wider with the increase of PKA energy. When the PKA energy is less than 10 keV, the number of defects will reach the peak within 1 ps, and then the system enters into the annihilation process and reaches to steady state within 20 ps. In addition to the incident energy, the incident direction of PKA also has a great influence on the cascade collision process and defect distribution. Compared with two other cases, <111> direction and <001> direction, PKAs along <011> direction produces significantly more defects, with a distribution more concentrated, and the defect recombination rate is also higher in the annihilation process. The evolution of different types of defects in the cascade collision process is different, and the number of O vacancies is the largest, followed by the number of O interstitial atoms, Zn interstitial atoms, and Zn vacancies. Some of the interstitial O atoms replace the Zn vacancies during the annihilation process.

Molecular Dynamic Simulation of Primary Damage with Electronic Stopping in Indium Phosphide.

Indium phosphide (InP) is an excellent material used in space electronic devices due to its direct band gap, high electron mobility, and high radiation resistance. Displacement damage in InP, such as vacancies, interstitials, and clusters, induced by cosmic particles can lead to the serious degradation of InP devices. In this work, the analytical bond order potential of InP is modified with the short-range repulsive potential, and the hybrid potential is verified for its reliability to simulate the atomic cascade collisions. By using molecular dynamics simulations with the modified potential, the primary damage defects evolution of InP caused by 1-10 keV primary knock-on atoms (PKAs) are studied. The effects of electronic energy loss are also considered in our research. The results show that the addition of electronic stopping loss reduces the number of point defects and weakens the damage regions. The reduction rates of point defects caused by electronic energy loss at the stable state are 32.2% and 27.4% for 10 keV In-PKA and P-PKA, respectively. In addition, the effects of electronic energy loss can lead to an extreme decline in the number of medium clusters, cause large clusters to vanish, and make the small clusters dominant damage products in InP. These findings are helpful to explain the radiation-induced damage mechanism of InP and expand the application of InP devices.

Rate theory coupling multi-phase-field simulation for neutron irradiation nanophase and vacancy evolution

Radiation damage is a critical problem for the alloys serving under irradiation circumstances where the numerous defects is induced by the cascade collision of radiation particles, the microstructure and mechanical properties will be damaged by the irradiation. By combination of rate theory (RT) and multi-phase-field (MPF) model, the influences of neutron irradiation dose rate (DR) and irradiation temperature are studied on the radiation-enhanced precipitation, vacancies and interstitial atoms in Fe-35Cr-10Al (at%) alloy. The RT coupled with phase-field simulations capture the radiation induced nanoscale precipitates, clustering of vacancies and interstitial atoms. With the increase of DR, the diffusion of solute atoms is accelerated for the generation of vacancies and interstitial atoms, and the growth and coarsening rate of α′ phase is quickened. The DR affects the distribution of elements between α/α′ phases, high DR promotes the Fe and Al to partition into α phase, Cr into α′ phase in the formation of α′ phase. Therefore, in the steady-state coarsening stage, the high DR leads to the α′ phase to reach the equilibrium composition earlier. As the increase of neutron irradiation temperature, the separation and coarsening rate of α′ phase are accelerated. The simulation morphology and quantitative characteristics are consistent with the experimental results. The coupling of RT and MPF simulation in alloys with point defects and nanophase under neutron irradiation put forward the study tactics and theory understanding for radiation-enhanced multiple microstructure evolutions.

Depth profiling of implanted D in silicates: Contribution of solar wind protons to water in the Moon and terrestrial planets

The solar wind protons implanted in silicate material and combined with oxygen are considered crucial for forming OH/H O on the Moon and other airless bodies. This process may also have contributed to hydrogen delivery to planetary interiors through the accretion of micrometre-sized dust and planetesimals during early stages of the Solar System. This paper experimentally investigates the depth distribution of solar wind protons in silicate materials and explores the mechanisms that influence this profile. We simulated solar wind irradiation by implanting 3 keV D ions in three typical silicates (olivine, pyroxene, and plagioclase) at a fluence of sim 1.4 × 10 ions/cm . Fourier transform infrared spectroscopy was used to analyse chemical bond changes, while transmission electron microscopy (TEM) characterised microstructural modifications. Nanoscale secondary ion mass spectrometry (NanoSIMS) was employed to measure the D/ O ratio and determine the depth distribution of implanted deuterium. The newly produced OD band (at 2400–2800 cm –1 ) in the infrared spectrum reveals the formation of O–D bonds in the irradiated silicates. The TEM and NanoSIMS results suggest that over 73<!PCT!> of the implanted D accumulated in fully amorphous rims with a depth of 70 nm, while 25<!PCT!> extended inwards to sim 190 nanometres, resulting in partial amorphisation. The distribution of these deuterium particles is governed by the collision processes of the implanted particles, which involve factors such as initial energy loss, cascade collisions, and channelling effects. Furthermore, up to 2<!PCT!> of the total implanted D penetrated the intact lattice via diffusion, reaching depths ranging from hundreds of nanometres to several micrometres. Our results suggest that implanted solar wind protons can be retained in silicate interiors, which may significantly affect the hydrogen isotopic composition in extraterrestrial samples and imply an important source of hydrogen during the formation of terrestrial planets.

Establishing the temperature and orientation dependence of the threshold displacement energy in ThO2 via molecular dynamics simulations

ThO2 is a promising fuel for next-generation nuclear reactors. As a critical quantity measuring its radiation tolerance, the dependence of the threshold displacement energy on temperature and crystal orientation in ThO2 is unclear and established using comprehensive molecular dynamics simulations in this work. For both Th and O primary knock-on atoms (PKAs), the thresholds, denoted as EdTh and EdO, respectively, are calculated using two different interatomic potentials. Similar temperature and orientation dependence are observed, albeit with some quantitative differences. While on average over all orientations, higher energy is required for Th PKAs than O PKAs to displace atoms, the polar-averaged EdTh is significantly lower than that for EdO. Further, EdTh and EdO show different crystal orientation dependence and temperature dependence. Notably, the cubic symmetry in the fluorite structure is followed by EdTh, but does not hold for EdO because of the existence of two sublattices. The much higher average EdO than EdTh and their different temperature dependence are interpreted by the distinct recombination rates of Th and O Frenkel pairs in thermal spikes, resulting from the substantially lower migration barriers of O vacancies and interstitials. The recombination of O vacancies and interstitials, both of which are charged, is further enhanced by the Coulomb interaction at small Frenkel pair separations. The new findings are discussed for their generality in fluorite-structured oxides by comparing the results in ThO2 and UO2.

Low-dose neutron irradiation effects on the elastoplastic deformation mechanisms of aluminum-doped gallium nitride under contact loading

The elastoplastic deformation mechanisms of irradiated aluminum (Al)-doped gallium nitride (GaN) under contact loading are investigated in this work using the nanoindentation simulations, which is of great significance for understanding the mechanical properties of the Al-doped GaN and guiding the design of durable and high-performance GaN-based devices. The mechanical behaviors of the Al-doped GaN with different doping concentrations are analyzed, including the indentation hardness, Young's modulus, elastic recovery rates, phase transformations, and stress distribution. It is found that Al doping increases their hardness, Young's modulus, and elastic recovery rates, and leads to an enlargement of the phase transformation regions, which is dominated by the high coordination number (CN) phase transformations. Furthermore, the effects of low-dose neutron irradiation on their elastoplastic deformation mechanisms are studied by triggering cascade collisions within the structure. When subjected to such irradiation, structural changes occur in the Al-doped GaN, their indentation hardness, Young's modulus, and elastic recovery rates increase remarkably, and its phase transformation mechanism is changed remarkably. The dislocation behaviors of the doped and undoped GaN are different under neutron irradiation. This study is important for capturing the mechanical stability and integrity of Al-doped GaN in an irradiation environment, as well as developing GaN-based devices with superior irradiation resistance.

Determining the carbon detection limit with magnetic sector dynamic secondary ion mass spectrometry (SIMS)

Dynamic SIMS is often used to evaluate the concentration of impurities in solids because of its high sensitivity, depth profiling capabilities, good depth resolution, and high throughput. Continuous ion beam sputtering with a high-density primary beam provides high sensitivity and reduces the background contribution from residual gases within the analytical chamber. Dynamic SIMS experiments performed with several magnetic sector instruments using various sputtering rate conditions demonstrated a slow decrease of the carbon detection limit with the increase of sputtering rate (SR), when it was varied by changing the sputtering beam density. The dependence data, within the scatter limits, can be fit by a power function of SR with the exponent of about −1/2. The observed detection-limit-dependence curve is common for magnetic sector SIMS instruments, owing to contamination and the design of the analytical chamber. The depth resolution of light-element SIMS analysis (except for oxygen) performed using Cs+ sputtering is limited and cannot be improved by reducing the impact energy of the sputtering beam. A segregation-type depth profile with a long trailing edge was observed in the B, C, and N depth profiles when Cs+ sputtering was employed under ultra-high vacuum conditions. This effect is plausibly associated with preferential sputtering owing to the difference in the surface binding energy, along with the large difference in the mass of the interacting atoms within the collision cascade during sputtering. The depth resolution improved with surface oxidation when Cs + sputtering was combined with backfilling of the analytical chamber using O2. The analytical chamber backfilled with oxygen can be sufficiently replaced with a very low-impact energy-focused oxygen beam, enabling simultaneous oxygen and cesium co-sputtering SIMS analysis. The practical feasibility of using a co-sputtering with focused Cs+ and O2+ sputtering beams to achieve a high depth-resolution for carbon analysis under ultrahigh vacuum conditions was demonstrated.