Buildup Of Density Research Articles

First integrated core-edge fluid simulation of ITER’s Limiter–Divertor transition with SolEdge-HDG

This work explores the Limiter–Divertor transition (L–D) during the current ramp-up of ITER’s Q = 10 baseline plasma scenario at various central line-integrated density nli values. The analysis, based on transport simulations performed with the latest version of SoleEdge-HDG, focuses on the time evolution of heat and ion particle fluxes, revealing regions of elevated temperature on the inner wall and plasma-facing components (PFCs) despite moderate loads. The investigation also delves into the effects of perpendicular convection flux terms on density build-up, comparing different formulations and their interplay with auxiliary heating sources. Furthermore, the paper shows the impact of taking into account the evolution of the parallel neutral momentum on plasma and neutral density at the targets in the context of an ITER steady-state scenario.

Nematode-suppressive and plant growth-enhancing effects of Citrus spp. derivatives against Meloidogyne incognita on tomato

Plant-based derivatives (powders, pellets or extracts) are amongst the most effective types of organic soil amendments for the management of root-knot nematodes (Meloidogyne spp.). The objective of this study was to examine the effect of derivatives (juice, powder and oil) of fruits of several Citrus species (sweet orange, lemon, lime, mandarin and grapefruit) on the reproduction of Meloidogyne incognita race 2 on susceptible tomato plants, and on the vegetative growth of the crop under glasshouse conditions. Results show that juices of sweet orange, and possibly also lemon, applied as soil amendments either before planting or after planting, can significantly suppress the build-up of damaging root population densities of M. incognita on infected tomato plants, limit root galling and improve plant growth. Data confirm the nematode-suppressive and plant-growth enhancing effects reported for Citrus fruit-based plant derivatives, applied either as a compost, powder, extract or pellet.

Mechanical properties, elastic moduli, and gamma ray attenuation competencies of some TeO2–WO3–GdF3 glasses: Tailoring WO3–GdF3 substitution toward optimum behavioral state range

Abstract We report the mechanical properties, elastic moduli, and gamma ray attenuation properties of some TeO2–WO3–GdF3 glasses. Using the chemical composition of the selected glasses, the dissociation energy per unit volume (G t ) and the packing density (V t ) were calculated. Using the G t and V t values, Young’s, Shear, Bulk, Longitudinal Modulus, and Poisson’s ratio of the glasses are calculated. Next several fundamental gamma ray attenuation properties such as linear and mass attenuation coefficients, half value layer, mean free path, effective atomic number, effective electron density, effective conductivity, exposure, and energy absorption buildup factors are calculated in 0.015–15 MeV energy range. As a consequence of WO3–GdF3 substitution, the glass densities are observed in different values. The overall gamma ray attenuation properties are found to be enhanced through WO3 addition. Moreover, the increasing WO3 incorporation into glass configuration decreases the overall elastic moduli of glasses. It can be concluded that increasing WO3 may be a useful tool for enhancing the gamma ray attenuation qualities and decreasing the elastic moduli of TeO2–WO3–GdF3 in situations where a material with versatile mechanical properties is required.

Analyses of Gamma and Neutron Attenuation Properties of the AA6082 composite material doped with boron carbide (B4C)

Aluminum Alloy AA6082 + (0–40%) B4C materials were analyzed in the energy range between 0.015 and 15 MeV by PSD software. The mass and linear attenuation coefficients (MAC, LAC), tenth-half value layers (TVL, HVL), mean-free path (MFP), effective atomic number (Zeff), equivalent atomic number (Zeq), fast neutron removal cross-section (FNRC), electron density (Neff), effective conductivity (Ceff), and exposure buildup factors (EBFs) parameters were computed for the energy range between 0.015 and 15 MeV. The research implied that LAC and MAC values in the Aluminum Alloy AA6082 functionally graded composite materials increased with the reduction in the B4C contents in the studied material. EBFs under the penetration depth of up to 40 mfp in the energy range between 0.015 and 15 MeV were computed by employing the Geometric-Progression method. TVL, FNRC, Ceff, and Neff values varied between 0.01 and 0.452 cm, 7.918–10.527 cm-1, 5.47.1010–8.31.1010 S/m, 2.90.1025–4.34.1025 electrons/g, respectively. AA6082 material showed the maximum photon shielding performance owing to having the lowest TVL and HVL values, and the highest Zeff and MAC values while AA6082 + 40% B4C material showed the maximum neutron shielding performance because of its higher density.

Initial grain orientation controls static recrystallization outcomes in cold-worked iron: Insight from coupled crystal plasticity/vertex dynamics modeling

Recrystallization of metallic materials is an important metallurgical treatment to bring cold-worked alloys to a usable state. Static recrystallization (SRX) occurs after deformation, once the material has built up sufficient plastic strain energy to trigger grain boundary motion. However, we have very limited knowledge about the combined effects on recrystallization kinetics of temperature, amount of cold working, triple junction mobility, and level of recovery in the deformed microstructure. In particular, little is still known about the microstructural factors that control the onset of SRX. Here we develop a comprehensive physical model based on coupling crystal plasticity and grain boundary kinetics utilizing curvature and differential plastic strain energy as driving forces for SRX in polycrystalline iron. The model links finite-element polycrystal plasticity simulations with a two-dimensional vertex dynamics approach, and is used to probe the large parameter space influencing static recrystallization. Our main finding is that the initial texture (defined by the polycrystal’s grain orientation and size distribution) is the dominant feature triggering and controlling SRX kinetics. We find a direct correlation between the degree of dislocation density buildup and the relative grain orientation across a grain boundary at the beginning of the deformation phase. Indeed, analysis of our results points to the maximum Schmid factor of a grain as the best predictor for activation of its grain boundaries during the recrystallization phase. We also find that the amount of post-deformation recovery only has a limited effect on the evolution of the recrystallized microstructure. Finally, using a definition based on the rate of transformation of the material, we find a recrystallization temperature of 600 ∘C, consistent with experimental observations in high-purity iron specimens.

Discrete dislocation modelling of δ hydrides in Zr: towards an understanding of the importance of interfacial stresses for crack initiation

We carried out discrete dislocation plasticity (DDP) simulations in the infinite-matrix approximation of δ Zr micro-hydrides – including their elastic field - first precipitating in Zr and then subjected to an external stress. We calculate and present the dislocation density, maximum principal shear and stresses, configurational energy density and plastic displacement. It was found that even hydrides as thin as 20 nm have a large impact on dislocation density, plastic deformation and stress build-up, and that this effect increases for increasing hydride thickness. It also appears that the critical location for crack nucleation is at the Zr/hydride interface. In fact, slip bands that develop on one side of the interface, and are stopped by it, are accompanied by the formation of high stresses. The observation that the interfacial stress is the only way in which hydrides are represented in the simulations, with no point obstacles or change in the slip systems at the interface, combined with the observed strong influence of the hydrides on the results, suggests a possible mechanistic explanation for the embrittlement caused by the precipitation of intragranular hydrides. The mechanism is rooted in the volumetric expansion upon precipitation and naturally includes a thickness dependence that is also experimentally observed.

JINTRAC integrated simulations of ITER scenarios including fuelling and divertor power flux control for H, He and DT plasmas

We have modelled self-consistently how to most efficiently fuel ITER hydrogen (H), helium (He) and deuterium–tritium (DT) plasmas with gas and/or pellets with the integrated core and 2D SOL/divertor suite of codes JINTRAC. This paper presents the first overview of full integrated simulations from core to divertor of ITER scenarios following their evolution from X-point formation, through L-mode, L–H transition, steady-state H-mode, H–L transition and current ramp-down. Our simulations respect all ITER operational limits, maintaining the target power loads below 10 MW m−2 by timely gas fuelling or Ne seeding. For the pre-fusion plasma operation (PFPO) phase our aim was to develop robust scenarios and our simulations show that commissioning and operation of the ITER neutral beam (NB) to full power should be possible in 15 MA/5.3 T L-mode H plasmas with pellet fuelling and 20 MW of ECRH. For He plasmas gas fuelling alone allows access to H-mode at 7.5 MA/2.65 T with 53–73 MW of additional heating, since after application of NB and during the L–H transition, the modelled density build-up quickly reduces the NB shine-through losses to acceptable levels. This should allow the characterisation of ITER H-mode plasmas and the demonstration of ELM control schemes in PFPO-2. In ITER DT plasmas we varied the fuelling and heating schemes to achieve a target fusion gain of Q = 10 and to exit the plasma from such conditions with acceptable divertor loads. The use of pellets in DT can provide a faster increase of the density in L-modes, but it is not essential for unrestricted NB operation due to the lower shine-through losses compared to H. During the H–L transition and current ramp-down, gas fuelling and Ne seeding are required to keep the divertor power loads under the engineering limits but accurate control over radiation is crucial to prevent the plasma becoming thermally unstable.

The Role of Spin-Flip Collisions in a Dark-Exciton Condensate

We show that a Bose-Einstein condensate consisting of dark excitons forms in GaAs coupled quantum wells at low temperatures. We find that the condensate extends over hundreds of micrometers, well beyond the optical excitation region, and is limited only by the boundaries of the mesa. We show that the condensate density is determined by spin-flipping collisions among the excitons, which convert dark excitons into bright ones. The suppression of this process at low temperature yields a density buildup, manifested as a temperature-dependent blueshift of the exciton emission line. Measurements under an in-plane magnetic field allow us to preferentially modify the bright exciton density and determine their role in the system dynamics. We find that their interaction with the condensate leads to its depletion. We present a simple rate-equations model, which well reproduces the observed temperature, power, and magnetic-field dependence of the exciton density.

3D MHD wave propagation near a coronal null point: New wave mode decomposition approach

Context. Ubiquitous vortex flows at the solar surface excite magnetohydrodynamic (MHD) waves that propagate to higher layers of the solar atmosphere. In the solar corona, these waves frequently encounter magnetic null points. The interaction of MHD waves with a coronal magnetic null in realistic 3D setups requires an appropriate wave identification method. Aims. We present a new MHD wave decomposition method that overcomes the limitations of existing wave identification methods. Our method allows for an investigation of the energy fluxes in different MHD modes at different locations of the solar atmosphere as waves generated by vortex flows travel through the solar atmosphere and pass near the magnetic null. Methods. We used the open-source MPI-AMRVAC code to simulate wave dynamics through a coronal null configuration. We applied a rotational wave driver at our bottom photospheric boundary to mimic vortex flows at the solar surface. To identify the wave energy fluxes associated with different MHD wave modes, we employed a wave decomposition method that is able to uniquely distinguish different MHD modes. Our proposed method utilizes the geometry of an individual magnetic field-line in the 3D space to separate the velocity perturbations associated with the three fundamental MHD waves. We compared our method with an existing wave decomposition method that uses magnetic flux surfaces instead. Over the selected flux surfaces, we calculated and analyzed the temporally averaged wave energy fluxes, as well as the acoustic and magnetic energy fluxes. Our wave decomposition method allowed us to estimate the relative strengths of individual MHD wave energy fluxes. Results. Our method for wave identification is consistent with previous flux-surface-based methods and provides the expected results in terms of the wave energy fluxes at various locations of the null configuration. We show that ubiquitous vortex flows excite MHD waves that contribute significantly to the Poynting flux in the solar corona. Alfvén wave energy flux accumulates on the fan surface and fast wave energy flux accumulates near the null point. There is a strong current density buildup at the spine and fan surface. Conclusions. The proposed method has advantages over previously utilized wave decomposition methods, since it may be employed in realistic simulations or magnetic extrapolations, as well as in real solar observations whenever the 3D fieldline shape is known. The essential characteristics of MHD wave propagation near a null – such as wave energy flux accumulation and current buildup at specific locations – translate to the more realistic setup presented here. The enhancement in energy flux associated with magneto-acoustic waves near nulls may have important implications in the formation of jets and impulsive plasma flows.

Gamma, neutron, and heavy charged ion shielding properties of Er3+-doped and Sm3+-doped zinc borate glasses

AbstractThis study aimed to investigate the nuclear radiation shielding properties of erbium (Er)-reinforced and samarium (Sm)-reinforced borate glasses. In the 0.015–15 MeV photon energy range, attenuation coefficients, as well as half-value layer tenth-value layers, and the mean-free path have been calculated. Additionally, effective, and equivalent atomic numbers, effective atomic weight, electron density, and exposure and energy absorption build-up factors were also calculated. To evaluate the overall nuclear radiation attenuation competencies of Er-rich and Sm-rich glasses, effective removal cross-section values for fast neutrons and projected range/mass stopping power values for alpha and proton particles were also determined. The glass sample BZBEr2.0 had the highest linear and mass attenuation coefficients (µandµm), effective conductivity (Ceff), the effective number of electrons (Neff), and effective atomic number (Zeff) values as well as the lowest half-value layer (T1/2), tenth value layers (T1/10), mean free path (λ), exposure build-up factor, and energy absorption build-up factor values.µmvalues were reported as 2.337, 2.556, 2.770, 2.976, 2.108, 2.266, 2.421, 2.569, and 2.714 for BZBEr0.5, BZBEr1.0, BZBEr1.5, BZBEr2.0, BZBSm0.0, BZBSm0.5, BZBSm1.0, BZBSm1.5, and BZBSm2.0 glass samples at 0.06 MeV, respectively. The results showed that Er has a greater effect than Sm regarding the gamma-ray shielding properties of borate glasses. The results of this investigation could be used in further investigations and added to older investigations with the same aim, to aid the scientific community in determining the most appropriate rare-earth additive, to provide adequate shielding properties based on the requirement.

Physical, structural and nuclear radiation shielding behaviour of xBaO-(0.30-x)MgO-0.10Na2O-0.10Al2O3-0.50B2O3 glass matrix

In the present investigations, six cylindrical shaped glass sample having chemical composition x BaO-(0.30-x) MgO-0.10Na2O-0.10Al2O3-0.50B2O3 (x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30 mol fraction) were prepared by melt quenching technique. The density, molar volume, oxygen packing density (OPD), oxygen molar volume (OMV), Poisson's ratio, barium inter ionic distance, Polaron radius and field strength were calculated for the prepared glass samples. The values of linear attenuation coefficients (LAC) were measured experimentally by using narrow beam transmission geometry in the gamma photon energy range of 59.54–1332 keV. In order to ascertain the application of the prepared glasses in the field of radiation protection and design, the values of LAC were used to calculate various gamma ray interaction parameters namely half value layer (HVL), Radiation Protection Efficiency (RPE), Mass Attenuation Coefficient (MAC), effective atomic number (Zeff), electron density (Ne) and Exposure Buildup Factors (EBFs). The values of fast neutron removal cross sections (∑R cm−1) were also calculated for the prepared glass matrix. The theoretical values of attenuation parameters were determined using online software Phy-X/PSD and FLUKA (Monte-Carlo) simulation code. Excellent agreements have been observed between experimental, theoretical and simulation results for the prepared glass samples. Furthermore, the radiation shielding properties for the prepared glass samples were compared with conventional used concretes and commercial radiation shielding glass (RS253 G-18). On the basis of the obtained results, it has been reported that the prepared glass samples possess satisfactory physical reliability and superior shielding efficiency against gamma rays and fast neutrons as compared to conventional/commercial shielding materials.

Influence of diameter on temperature dynamics of hot carriers in photoexcited GaAsP nanowires

Nanowires (NWs) with their quasi-one-dimensionality often present different structural and opto-electronic properties than their thin-film counterparts. The thinner they are the larger these differences are, in particular in the carrier-phonon scattering and thermal conductivity. In this work, we present femtosecond transient absorbance measurements on GaAs0.8P0.2 NWs of two different diameters, 36 and 51 nm. The results show that thinner NWs sustain the hot-carriers at a higher temperature for longer times than thicker NWs. We explain the observation suggesting that in thinner NWs, the build-up of a hot-phonon bottleneck is easier than in thicker NWs because of the increased phonon scattering at the NW sidewalls which facilitates the build-up of a large phonon density. The large number of optical phonons emitted during the carrier relaxation processes generate a non-equilibrium population of acoustic phonons that propagates less efficiently in thin NWs. This makes the possible acoustic-to-optical phonon up-conversion process easier, which prolongs the LO phonon lifetime resulting in the slowdown of the carrier cooling. The important observation that the carrier temperature in thin NWs is higher than in thick NWs already at the beginning of the hot carrier regime suggests that the phonon-mediated scattering processes in the non-thermal regime play a major role at least for the carrier densities investigated here (8x1018-4x1019 cm-3). Our results also suggest that the boundary scattering of phonons at crystal defects is negligible compared to the surface scattering at the NW sidewalls.

Over 15% efficient wide-band-gap Cu(In,Ga)S2 solar cell: Suppressing bulk and interface recombination through composition engineering

Over 15% efficient wide-band-gap Cu(In,Ga)S2 solar cell: Suppressing bulk and interface recombination through composition engineering

Earth-bound millicharge relics

Dark sector particles with small electric charge, or millicharge, (mCPs) may lead to a variety of diverse phenomena in particle physics, astrophysics, and cosmology. Assuming their possible existence, we investigate the accumulation and propagation of mCPs in matter, specifically inside the Earth. Even small values of millicharge lead to sizeable scattering cross sections on atoms, resulting in complete thermalization, and as a consequence, considerable build-up of number densities of mCPs, especially for the values of masses of GeV and higher when the evaporation becomes inhibited. Enhancement of mCP densities compared to their galactic abundance, that can be as big as ${10}^{14}$, leads to the possibility of new experimental probes for this model. The annihilation of pairs of mCPs will result in new signatures for the large volume detectors (such as Super-Kamiokande). Formation of bound states of negatively charged mCPs with nuclei can be observed by direct dark matter detection experiments. A unique probe of mCP can be developed using underground electrostatic accelerators that can directly accelerate mCPs above the experimental thresholds of direct dark matter detection experiments.

First-principles study of nickel reactivity under two-dimensional cover: Ni2C formation at rotated graphene/Ni(111) interface

Recent experiments indicate that the reactivity of metal surfaces changes profoundly when they are covered with two-dimensional (2D) materials. Nickel, the widespread catalyst choice for graphene (G) growth, exhibits complex surface restructuring even after the G sheet is fully grown. In particular, due to excess carbon segregation from bulk nickel to surface upon cooling, a nickel carbide (${\mathrm{Ni}}_{2}\mathrm{C}$) phase is detected under rotated graphene (RG) but not under epitaxial graphene (EG). Motivated by this experimental evidence, we construct different G/Ni(111) interface models accounting for the two types of G domains. Then, by applying density functional theory, we illuminate the microscopic mechanisms governing the structural changes of nickel surface induced by carbon segregation. A high concentration of subsurface carbon reduces the structural stability of Ni(111) surface and gives rise to the formation of thermodynamically advantageous ${\mathrm{Ni}}_{2}\mathrm{C}$ monolayer. We show the restructuring of the nickel surface under RG cover and reveal the essential role of G rotation in enabling high density of favorable C binding sites in the Ni(111) subsurface. As opposed to RG, the EG cover locks the majority of favorable C binding sites preventing the build-up of subsurface carbon density to a phase transition threshold. Therefore we confirm that the conversion of C-rich Ni surface to ${\mathrm{Ni}}_{2}\mathrm{C}$ takes place exclusively under RG cover, in line with the strong experimental evidence.

Buildup and decay dynamics of exponentially modulated quantum waves in resonant structures

We derive an exact analytic solution of time-dependent Schrödinger’s equation for cutoff quantum waves with exponential modulation to explore the dynamics along the internal region of a one-dimensional potential of arbitrary shape. The modulation of the wave packet is controlled by a single parameter given by its momentum distribution width, Δ, which allows to explore on the same footing the transient features of both cutoff spatially localized wave packets and extended plane waves. From the formal solution, we derive a simple and reliable formula that accurately describes both the buildup and decay of the probability density inside a resonant structure. The buildup-decay formula involves two exponential terms governed respectively by the resonance width Γ1 of the lowest resonance of the system and the width of a ‘virtual’ state induced by the incident wave packet. During the buildup process, we demonstrate that the contributions of both Γ1 and become essential. In the decay process, on the other hand, we find that there are two regimes characterized by a critical value Δc, such that for Δ > Δc the exponential decay is governed by Γ1, while for Δ < Δc the exponential decay is governed by . We also derive an analytic formula for a relevant timescale for the buildup-decay process, which depends in a simple fashion on the decay rates Γ1 and . Deviations from the exponential decay law at long times are also discussed.

Influence of microstructural heterogeneity and plastic strain on geometrically necessary dislocation structure evolution in single-phase and two-phase alloys

Deformation of single phase and two phase materials can be heterogeneous depending on the grain size distribution, orientation of the grains, amount and arrangement of the second phase and phase transformation during plastic deformation and twins. The deformation heterogeneity requires generation of geometrically necessary dislocations (GND) to maintain contact of the deforming grains and phases. Depending on the amount and character of deformation at the microscopic length scale, the evolution of the GND density changes. The present paper discusses the buildup of the GND density in different microstructural configurations using, single phase ferritic interstitial free (IF) steel, dual phase (DP) steel containing ferrite and martensite and austenitic stainless steel prone to deformation induced martensitic transformation and twining and whether GND density can be used as a descriptor of the deformation characteristics of the materials. The estimation of GND content using electron backscatter diffraction (EBSD) is recognized. The application potential of the present study is in understanding the in-grain deformation behavior of single phase IF steel, two phase DP steel, transformation induced plasticity assisted austenitic stainless steel to assess the forming of the steels for automobile applications. It should also facilitate the validation of strain gradient plasticity dependent damage model.

Assessment of gamma-ray attenuation features for La+3 co-doped zinc borotellurite glasses

In this study, gamma ray and neutrons shielding features were evaluated for La+3 co-doped zinc borotellurite glasses with chemical formula {[(TeO2)0.70(B2O3)0.30]0.7(ZnO)0.30}1-x(La2O3)x: 0.01≤ x ≤ 0.05 mol%. Firstly, the mass and linear attenuation coefficients (MAC, LAC) for glasses were calculated via Photon Shielding and Dosimetry (PSD) software (Phy-X/PSD) in the energy range of 0.015–15 MeV. Depending on MAC and LAC, effective shielding parameters: Half value layer and mean free path (HVL, MFP), effective electron density, atomic number, and conductivity (Neff, Zeff, Ceff), exposure and energy absorption buildup factors (EBF, EABF) have been evaluated. In addition, effective fast neutron removal cross section (FNRCS) for the studied glasses have been calculated. The obtained data were compared with those of some commercial glasses and concrete. Results reveal that HVL for all samples can be arranged in the order TBZL1>TBZL2>TBZL3>TBZL4>TBZL5. The HVL, TVL and MFP values of TBZL5 glass are 2.988 cm, 9.927 cm, and 4.311 cm, respectively. TBZL5 glass has the highest Ceff values and TBZL1 glass has the lowest Ceff values. EBF values change range from 1 to 4 at 1 MFP and from 1-1010 at 40 MFP value. Therefore, it can be among the alternative materials that can be preferred in radiation application areas.

Laser-driven tunneling photocurrent as a source of midinfrared to microwave multidecade supercontinua yoked to high-order harmonics

Electron tunneling induced by a strong-field laser driver can lead to an ultrafast stepwise buildup of the photoelectron density \ensuremath{\rho}. When the laser field is strong enough, each such step in the temporal profile of \ensuremath{\rho} is confined well within the field cycle, providing an ultrabroadband, multidecade force that drives the photoelectron current $j$. However, whether or not the photocurrent can emit electromagnetic radiation with such an extraordinarily broad spectrum depends on the damping, which defines the low-frequency cutoff in the spectrum of this radiation. We show that, with a suitable choice of the gas pressure and parameters of the laser driver, the laser-induced tunneling photocurrent can serve as a source of a remarkably broadband electromagnetic radiation with a multidecade spectrum stretching from the vacuum ultraviolet all the way down to the microwave range. We demonstrate that the supercontinuum fields emitted by individual photocurrent steps, induced by different field half cycles, can coherently combine, giving rise to well-resolved high-order harmonics on the high-frequency end of the spectrum yoked to a bright midinfrared to microwave supercontinuum, dominating the long-wavelength part of the multidecade radiation output.

Construction of a linear plasma device for studying helicon plasmas relevant to plasma-wakefield accelerators

The magnetized anisotropic ion apparatus (MARIA) was constructed to study the density buildup and particle balance in helicon plasmas. This device will help address key questions surrounding the dynamics of the neutral argon population and the role it plays in defining the ultimate density achieved. Insights gained from this research are particularly important for meeting the demanding high density and high uniformity requirements of plasma based wakefield accelerator concepts. A key feature of the MARIA device is it is fully transparent borosilicate glass chamber which enables the flexible use and development of optical techniques for measuring plasma parameters like electron temperature and density. Whistler-mode behavior featuring very high on-axis ionization fraction and a linear relationship between electron density and magnetic field strength up to 5 × 1018 m−3 has been measured with an RF compensated Langmuir probe in argon with 700 W RF power, 650 G at the antenna, and 2 mTorr neutral pressure. Laser induced fluorescence measurements, which build on the Langmuir probe measurements, are able to fully constrain the 2D particle balance by enabling ion and neutral sources and sinks to be spatially resolved. Initial flow velocity measurements in the axial direction are presented.