Light Ions Research Articles

A Chelating Resin of EDTA-Type Modified Cross-Linking Polystyrene to Preconcentrate Trace Metals for Seawater Detection.

The determination of trace metals in seawater is an important project of marine environmental monitoring. However, the presence of many alkali metal ions with high concentration, such as sodium ion, seriously interferes with the detection limit and accuracy of atomic absorption spectrometry (AAS, flame/graphite furnace integrated). The conventional chemical methods for the enrichment of trace metals are complex, and low boiling point organic solvents are used. In this paper, a kind of commercial cross-linked polystyrene resin microspheres was chloromethylated and aminated to introduce EDTA-type amino polycarboxylic groups and then loaded in a column as the absorption filler. A set of seawater pretreatment and enrichment devices was designed and assembled. The enriching process and conditions of trace Cu, Zn, Pb, and Cd in standard seawater were studied. 10 g of the modified resin could enrich the equivalent seawater and remove successfully the light metal ions. pH = 5∼9 and 0.2 mL/min of the flow rate were the suitable conditions for preconcentration. The enriched metal ions in the eluent were analyzed on the AAS. Compared with the conventional solvent method, the novel material and enrichment device have high preconcentration efficiency, strong anti-interference ability, and low cost and could be directly applied for routine seawater detection.

Micro Raman analysis on the impact of light ion irradiation of hydride vapor-phase epitaxy grown gallium nitride epilayers

Gallium Nitride (GaN) epilayer grown by Hydride Vapor-Phase Epitaxy was irradiated with 100 MeV O7+ light ions for different fluences. The X-ray diffraction results confirmed that all the grown epilayers have wurtzite structure. The thickness of the pristine GaN is measured by cross-section scanning electron microscopy. From atomic force microscopy, the irradiated sample's surface morphology and root mean square values were analyzed. The stopping range of ions in the materials calculation provided the projected range for the irradiation ions. From Raman spectroscopy, Raman active mode of EH2 and A1(LO) vibration was observed. These Raman modes were fitted by the Lorentz fitting method for line-shape model identification to calculate the area under the curve, full-width half maximum, and peak shift position. The biaxial stress, carrier concentration, and phonon lifetime for both pristine and irradiated GaN epilayers were obtained from the Raman active mode. The results indicated that the carrier concentration increases for higher fluences due to the defect formations. The photoluminescence spectrum was measured for all the epilayers and defect-induced photoluminescence emission was obtained for these irradiation epilayers.

Calculated energy loss of swift light ions in platinum and gold: importance of the target electronic excitation spectrum

Understanding and predicting the energy loss of swift ions in metals is important for many applications of charged particle beams, such as analysis and modification of materials, and recently for modelling metal nanoparticle radiosensitisation in ion beam cancer therapy. We have calculated the stopping power of the transition metals Pt and Au for protons and alpha particles in a wide energy range, using the dielectric formalism, which realistically accounts for the excitation spectrum of each metal through the Mermin Energy Loss Function - Generalised Oscillator Strength methodology. For each combination of projectile, energy and target, we have considered: (i) the equilibrium charge state of the projectile through the target, (ii) the energy-loss due to electron capture and loss processes, and (iii) the energy loss resulting from the polarisation of the projectile’s electronic cloud due to the self-induced electric field. Our calculated stopping powers show a fairly good agreement with the available experimental data for platinum and gold, particularly the most recent ones around the stopping power maximum, which validates the methodology we have used to be further extended to other transition metals. For the materials studied (platinum and gold), two commonly used and different sources of the experimental excitation spectrum yield comparable calculated stopping powers and mean excitation energies, the latter being closer to the most recent data provided in a recent ICRU Report than to previous compilations. Despite the small differences in the sources of excitation spectra of these metals, they lead to practically the same stopping power results as far as they reproduce the main excitation features of the material and fulfil physically motivated sum rules.

Glossary of Terms and Concepts in Medical Padiation Physics. Terminology in Proton and Light Ion Beam Radiation Therapy

Medical radiation physics supports medical diagnostic and treatment process based on the use of ionizing
 radiation in radiation therapy, nuclear medicine, radiation diagnostics and radiation safety of patients and
 personnel. However, the successful implementation of this process requires close interaction of specialists
 in all the above areas. The basis of such interaction is the unification of the terminology and concepts used
 at various stages of the diagnostic and treatment process. This development is very important for high technological applications such as proton and light ion beam radiation therapy, where the description and correct and unambiguous interpretation of the terminology in the Russian-language literature is practically
 absent. The article presents a glossary on proton and light ion beam radiation therapy which contains the
 most commonly used terms in this field and explanations for each of them. The glossary is intended for use
 both in professional education, including postgraduate education, and for medical physicists and radiation
 oncologists working in radiological medical organizations

Construction of novel nitrogen-rich covalent organic frameworks for highly efficient La(III) adsorption

Two novel N-rich covalent organic frameworks (COFs), named COF-TZ-TP and COF-TA-TP, were prepared via a one-step solvothermal method and employed as the adsorbent to remove rare earth (RE) ions from solution. The as-prepared materials were characterized with XRD, FESEM, ATR-IR, BET, TGA and XPS analysis. The results show the rapid adsorption kinetics of La(III) with capacities of 165.6 and 89.8 mg/g for COF-TZ-TP and COF-TA-TP after 3 h. Moreover, Langmuir isotherm model and pseudo-second-order kinetic model are well fitted to describe the La(III) adsorption process. The analysis of the adsorption thermodynamic shows that the adsorption process is a spontaneous exothermic process with ΔS0 of 57.22 and 84.09 J/(mol ∙ K) for COF-TZ-TP and COF-TA-TP, respectively. In addition, the fabricated COFs exhibit the better adsorption results towards the light RE ions compared with heavy ones and the excellent reusability after five adsorption-regeneration cycles. The adsorption mechanism reveals that the splendid adsorption performance of RE for our N-rich COFs is mainly attributed to the surface coordination interaction between the N element and La(III) according to the characterization analysis for COF-TZ-TP before and after the adsorption process with elemental mapping, EDS and XPS. Therefore, these COFs with abundant active N sites offer the highly efficient adsorption capacity of La(III), and provide the promising strategy for the recovery of light RE from waste rare earth devices.

Efficacy of inertial confinement fusion experiments in light ion fusion cross section measurement at nucleosynthesis relevant energies

Inertial confinement fusion (ICF) experiments create a unique laboratory environment in which thermonuclear fusion reactions occur within a plasma, with conditions comparable to stellar cores and the early universe. In contrast, accelerator-based measurements must compete with bound electron screening effects and beam stopping when measuring fusion cross sections at nucleosynthesis-relevant energies. Therefore, ICF experiments are a natural place to study nuclear reactions relevant to nuclear astrophysics. However, analysis of ICF-based measurements must address its own set of complicating factors. These include: the inherent range of reaction energies, spatial and temporal thermal temperature variation, and kinetic effects such as species separation. In this work we examine these phenomena and develop an analysis to quantify and, when possible, compensate for their effects on our inference. Error propagation in the analyses are studied using synthetic data combined with Markov Chain Monte Carlo (MCMC) machine learning. The novel inference techniques will aid in the extraction of valuable and accurate data from ICF-based nuclear astrophysics experiments.

First-principles simulation of light-ion microscopy of graphene

The extreme sensitivity of 2D materials to defects and nanostructure requires precise imaging techniques to verify presence of desirable and absence of undesirable features in the atomic geometry. Helium-ion beams have emerged as a promising materials imaging tool, achieving up to 20 times higher resolution and 10 times larger depth-of-field than conventional or environmental scanning electron microscopes. Here, we offer first-principles theoretical insights to advance ion-beam imaging of atomically thin materials by performing real-time time-dependent density functional theory simulations of single impacts of 10–200 keV light ions in free-standing graphene. We predict that detecting electrons emitted from the back of the material (the side from which the ion exits) would result in up to three times higher signal and up to five times higher contrast images, making 2D materials especially compelling targets for ion-beam microscopy. This predicted superiority of exit-side emission likely arises from anisotropic kinetic emission. The charge induced in the graphene equilibrates on a sub-fs time scale, leading to only slight disturbances in the carbon lattice that are unlikely to damage the atomic structure for any of the beam parameters investigated here.

Coordination Chemistry-Driven Approaches to Rare Earth Element Separations.

Current projections for global mining indicate that unsustainable practices will cause supply problems for many elements, called critical raw materials, in the next 20 years. These include elements necessary for renewable technologies as well as artisanal sources. Energy critical elements (ECEs) comprise a group used for clean, renewable energy applications that are in low abundance in the Earth's crust or require an economic premium to extract from ores. Sustainable practices of acquiring ECEs is an important problem to address through fundamental research to provide alternative energy technologies such as wind turbines and electric vehicles at cheaper costs for our global energy generation and usage. Some of these green technologies incorporate rare-earth (RE) metals (Sc, Y and the lanthanides), which are challenging to separate from mineral sources because of their similar sizes (i.e., ionic radii) and chemical properties. The current process used to provide REs at requisite purities for these applications is counter-current solvent-solvent extraction, which is scalable and works efficiently for any ore composition. However, this method produces large amounts of caustic waste that is environmentally damaging, especially to areas in China that house major separation facilities. Advancement of the selectivity of this process is challenging since exact molecular speciation that affords separations is still relatively unknown. In this context, we developed a program to investigate new RE separations systems that were aimed at minimizing solvent use, controlled by molecular speciation, and could be targeted at problems in recycling these critical metals.The first ligand system that was developed to impart solubility differences between light and heavy rare-earth ions was [{(2-tBuNO)C6H4CH2}3N]3- (TriNOx3-) (graphic below). A differential solubility allowed for a separation of Nd and Dy of SFNd:Dy = ∼300 in a single step. In other words, a 50:50 Nd/Dy sample was enriched to give 95% pure Nd and Dy through a simple filtration, which is potentially impactful to recycling magnetic materials found in wind turbines. This separations system compares favorably to other state-of-the-art molecular extractants that are based on energetic differences of the thermodynamic parameter to affect separations for neighboring elements. This straightforward, thermodynamically driven method to separate REs primed our future research for new coordination chemistry approaches to separations.Another separations system was accomplished through the variable rate of a redox event from one arm of the TriNOx3- ligand. It was determined that the rate of this one electron oxidation, which operated through an electrochemical-chemical-electrochemical mechanism, was dependent on the identity of the RE ion. This kinetically driven separation afforded a separation factor (SF) of SFEu:Y = 75. We have also described other transformations such as ligand exchange, substituent dependent, and redox-driven chelation processes with well-defined speciation to afford purified RE materials. Recently, we determined that magnetic properties can be used to enhance both thermodynamic and kinetic RE separations processes to give an approximately 100% boost for pairs of paramagnetic/diamagnetic REs. These results have shown that both thermodynamic and kinetic RE separations were efficient for different selected RE binary pairs through coordination chemistry. The focus of this Account will detail the differences that are observed for RE separations when promoted by thermodynamic or kinetic factors. Overall, the development of rationally adjusted speciation of REs provides a basis for future industrial separations processes for technologies applied to ECEs derived from wind turbines, batteries for electric vehicles, and LEDs.

Functional Characterization and Phenotyping of Protoplasts on a Microfluidics-Based Flow Cytometry.

A better understanding of the phenotypic heterogeneity of protoplasts requires a comprehensive analysis of the morphological and metabolic characteristics of many individual cells. In this study, we developed a microfluidic flow cytometry with fluorescence sensor for functional characterization and phenotyping of protoplasts to allow an unbiased assessment of the influence of environmental factors at the single cell level. First, based on the measurement of intracellular homeostasis of reactive oxygen species (ROS) with a DCFH-DA dye, the effects of various external stress factors such as H2O2, temperature, ultraviolet (UV) light, and cadmium ions on intracellular ROS accumulation in Arabidopsis mesophyll protoplasts were quantitatively investigated. Second, a faster and stronger oxidative burst was observed in Petunia protoplasts isolated from white petals than in those isolated from purple petals, demonstrating the photoprotective role of anthocyanins. Third, using mutants with different endogenous auxin, we demonstrated the beneficial effect of auxin during the process of primary cell wall regeneration. Moreover, UV-B irradiation has a similar accelerating effect by increasing the intracellular auxin level, as shown by double fluorescence channels. In summary, our work has revealed previously underappreciated phenotypic variability within a protoplast population and demonstrated the advantages of a microfluidic flow cytometry for assessing the in vivo dynamics of plant metabolic and physiological indices at the single-cell level.

A review on reference dosimetry in radiation therapy with proton and light ion beams: status and impact of new developments

This review focuses on reference dosimetry of proton and light ion beams used for cancer treatments. The background is the recommendation from the International Atomic Energy Agency in the Technical Report Series 398 and the recent publication of the International Commission on Radiation Units and Measurements Report 93 (Prescribing, Recording, and Reporting Light Ion Beam Therapy). These recommendations are briefly summarised, focusing on protons and carbon ions, as the most used ion types worldwide. Following these guidelines, the different aspects involving absolute dose measurements with ionisation chambers are discussed. A description of the current challenges and adaptions for the future is given for new developments. One of them, with a direct impact on ionisation chambers, is the influence of magnetic fields since efforts are made to integrate magnetic resonance imaging techniques into ion beam treatments, allowing online imaging with high soft-tissue contrast. Additionally, upcoming treatments with helium beams call for more experimental studies and simulations characterising the response of ionisation chambers, and at the same time following the international recommendations. Lastly, since the use of helium ion beams may present the advantage of reduced number of secondary particles as compared to carbon ion beams, the role of secondary neutrons and their impact on secondary cancer incidence needs to be assessed.

Mixed-lanthanide clusters: A bridging approach that permits the design of molecular magnetic materials by introducing heavy lanthanides into the 3d-light lanthanide clusters without breaking structural integrity

Theoretical studies suggest that the ring 3d-4f clusters {MnIII4Ln4} may be a good material for magnetic refrigeration. However, only {MnIII4Ln4} constructed from light lanthanide ions have been obtained, while the attempt for their analogue containing the magnetically isotropic Gd(III) ions has failed. By applying the strategy of synthesizing mixed-lanthanide clusters, mixed-lanthanide clusters {MnIII4LaxGd4-x} and {MnIII4NdxGd4-x} without breaking structural integrity of {MnIII4Ln4} have been successfully made. It is found that smaller ionic radius difference between the lanthanides tends to increase the introduction of Gd(III) when applying the strategy. Moreover, the magnetic property measurements show that the obtained mixed-lanthanide clusters exhibit magnetothermal effect as predicted.

IAP TRIPLE-BEAM FACILITY FOR SIMULATION STUDIES OF RADIATION DAMAGE OF MATERIALS

The project of ion irradiation facility for in-situ studies of radiation damage being developed in IAP NAS of Ukraine is presented. The platform comprises 300 kV heavy ion implanter, 50 kV collinear dual-beam light ion implanter and 200 kV electron microscope. The optimal energies of heavy and light ion beams have been estimated. The results of computer simulation of ion transmission in the light ion implanter are presented.

Theoretical multiple-ionization cross sections of Ne-like molecules by light-ion impact: H2O

We present a simple theoretical model to calculate multiple-ionization cross sections (MICS) of Ne and Ne-like molecules (molecules with ten electrons as ${\mathrm{H}}_{2}\mathrm{O}, \mathrm{C}{\mathrm{H}}_{4}, \mathrm{N}{\mathrm{H}}_{3}$, and HF) for proton and light-ion impact, taking into account both direct and postcollisional emissions. In this paper, we tackle the case of water molecules, relevant to investigate the radiobiological effects of ion impact on living matter. The theory is developed in the framework of the independent electron model (IEM). To keep the model as simple as possible, we describe the impact parameter dependence of the single-particle ionization probabilities required by the IEM through decreasing exponential functions for each target orbital. We obtain the parameters of the exponential functions from the total net-ionization cross sections for each orbital by applying either the continuum distorted wave-eikonal initial-state (CDW-EIS) approximation or Rudd's model. We then calculate the contribution of Auger postcollisional electron emission to MICS by using the Ne postcollisional emission probabilities. This postcollisional treatment offers a very simple alternative to the much more complex molecular evaluation of postcollisional relaxation and provides results in close agreement with experimental data for proton and other light ions. We also demonstrate the relevance of considering postcollisional emission for water molecules after the $2{a}_{1}$ ($2s$ Ne-like) orbital direct ionization.

Electron transfer as a probe for relativistic effects in the ionization of atoms: Onset of electron transfer from benzene to heavy Group 11 and 12 transition metal cations

Mass spectrometric ICP-SIFT measurements are reported for the kinetics and product formation in reactions of Group 11 and Group 12 atomic cations with benzene, as well as hexafluorobenzene and carbon disulfide, all at 298 K in helium at 0.35 Torr. Ligation is observed to dominate with the lighter ions in these two triads, but electron transfer emerges dramatically with the third-row cations Au+ and Hg+. The latter is attributed to relativistic effects in the ionization energies of Au and Hg as predicted by quantum chemical calculations of non-relativistic and relativistic valence shell s-electron energies that render electron transfer thermoneutral or exothermic.

Influence of uranium dioxide and reflector surface on neutron yields of the nuclear hybrid fusion-fission reaction using MCUNED code

The goal of the present work is to demonstrate the effects of adding uranium dioxide (UO2) to deuterium fuel in the fusion-fission hybrid reactions. The effectiveness of applying a reflector surface on the neutron yield in D-D and D-UO2 reactions has been investigated. The neutrons yielded from the fusion reactions were considered as a neutron source for fission reactions. For this purpose, MCNPX and its extension, the MCUNED code, for D-D fusion processes and UO2 fission reactions were used to calculate the neutron yield and the generated power. Using externally evaluated nuclear data libraries, MCUNED is capable of light ion transport. The D (d), (n) 3He reaction with 0.25 gm of deuterium and the fission reactions with 0.25 and 1.0 gm of UO2 were utilized. The results showed that the calculated neutron flux from the D-D fusion reaction increased by a considerable amount when applying the reflector surface. Adding 1.0 gm of UO2 to deuterium fuel enhanced neutron flux by 4.95 times on average, outside the source with the reflector surface. The calculated power increased by about 3-folds when 1.0 gm of UO2 was added. Despite the narrow cross section of the D-D reactions used in this study, it was found that utilizing the reflector surface and UO2 or depleted uranium with restrictive high masses may be able to multiply the generated neutrons and the resulting power.

Quantifying Cellular Repair, Misrepair and Apoptosis Induced by Boron Ions, Gamma Rays and PRIMA-1 Using the RHR Formulation

The recent interaction cross-section-based formulation for radiation-induced direct cellular inactivation, mild and severe sublethal damage, DNA-repair and cell survival have been developed to accurately describe cellular repair, misrepair and apoptosis in TP53 wild-type and mutant cells. The principal idea of this new non-homologous repairable-homologous repairable (RHR) damage formulation is to separately describe the mild damage that can be rapidly handled by the most basic repair processes including the non-homologous end joining (NHEJ), and more complex damage requiring longer repair times and high-fidelity homologous recombination (HR) repair. Taking the interaction between these two key mammalian DNA repair processes more accurately into account has significantly improved the method as indicated in the original publication. Based on the principal mechanisms of 7 repair and 8 misrepair processes presently derived, it has been possible to quite accurately describe the probability that some of these repair processes when unsuccessful can induce cellular apoptosis with increasing doses of γrays, boron ions and PRIMA-1. Interestingly, for all LETs studied (≈0.3-160 eV/nm) the increase in apoptosis saturates when the cell survival reaches about 10% and the fraction of un-hit cells is well below the 1% level. It is shown that most of the early cell kill for low-to-medium LETs are due to apoptosis since the cell survival as well as the non-apoptotic cells agree very well at low doses and other death processes dominate beyond D > 1 Gy. The low-dose apoptosis is due to the fact that the full activation of the checkpoint kinases ATM and Chk2 requires >8 and >18 DSBs per cell to phosphorylate p53 at serine 15 and 20. Therefore, DNA repair is not fully activated until well after 1/2 Gy, and the cellular response may be apoptotic by default before the low-dose hyper sensitivity (LDHS) is replaced by an increased radiation tolerance as the DNA repair processes get maximal efficiency. In effect, simultaneously explaining the LDHS and inverse dose rate phenomena. The partial contributions by the eight newly derived misrepair processes was determined so they together accurately described the experimental apoptosis induction data for γ rays and boron ions. Through these partial misrepair contributions it was possible to predict the apoptotic response based solely on carefully analyzed cell survival data, demonstrating the usefulness of an accurate DNA repair-based cell survival approach. The peak relative biological effectiveness (RBE) of the boron ions was 3.5 at 160 eV/nm whereas the analogous peak relative apoptotic effectiveness (RAE) was 3.4 but at 40 eV/nm indicating the clinical value of the lower LET light ions (15 ≤ LET ≤ 55 eV/nm, 2 ≤ Z ≤5) in therapeutic applications to maximize tumor apoptosis and senescence. The new survival expressions were also applied on mouse embryonic fibroblasts with key knocked-out repair genes, showing a good agreement between the principal non-homologous and homologous repair terms and also a reasonable prediction of the associated apoptotic induction. Finally, the formulation was used to estimate the increase in DNA repair and apoptotic response in combination with the mutant p53 reactivating compound PRIMA-1 and γ rays, indicating a 10-2 times increase in apoptosis with 5 µM of the compound reaching apoptosis levels not far from peak apoptosis boron ions in a TP53 mutant cell line. To utilize PRIMA-1 induced apoptosis and cellular sensitization for reactive oxygen species (ROS), concomitant biologically optimized radiation therapy is proposed to maximize the complication free tumor cure for the multitude of TP53 mutant tumors seen in the clinic. The experimental data also indicated the clinically very important high-absorbed dose ROS effect of PRIMA-1.

A systematic study of the contribution of counting statistics to the final lineal energy uncertainty in microdosimetry

Objectives. Microdosimetry is proving to be a reliable and powerful tool to be applied in different fields such as radiobiology, radiation protection and hadron therapy. However, accepted standard protocols and codes of practice are still missing. With this regard, a systematic and methodical uncertainty analysis is fundamental to build an accredited uncertainty budget of practical use. This work studied the contribution of counting statistics (i.e. number of events collected) to the final frequency-mean and dose-mean lineal energy uncertainties, aiming at providing guidelines for good experimental and simulation practice. The practical limitation of current technologies and the non-negligible probability of nuclear reactions require careful considerations and nonlinear approaches. Approach. Microdosimetric data were obtained by means of the particle tracking Monte Carlo code Geant4. The uncertainty analysis was carried out relying on a Monte Carlo based numerical analysis, as suggested by the BIPM's ‘Guide to the expression of uncertainty in measurement’. Final uncertainties were systematically investigated for proton, helium and carbon ions at an increasing number of detected events, for a range of different clinical-relevant beam energies. Main results. Rare events generated by nuclear interactions in the detector sensitive volume were found to massively degrade microdosimetric uncertainties unless a very high statistics is collected. The study showed an increasing impact of such events for increasing beam energy and lighter ions. For instance, in the entrance region of a 250 MeV proton beam, about 5 ∗ 107 events need to be collected to obtain a dose-mean lineal energy uncertainty below 10%. Significance. The results of this study help define the necessary conditions to achieve appropriate statistics in computational microdosimetry, pointing out the importance of properly taking into account nuclear interaction events. Their impact on microdosimetric quantities and on their uncertainty is significant and cannot be overlooked, particularly when characterising clinical beams and radiobiological response. This work prepared the ground for deeper investigations involving dedicated experiments and for the development of a method to properly evaluate the counting statistics uncertainty contribution in the uncertainty budget, whose accuracy is fundamental for the clinical transition of microdosimetry.

Characterization of ion-induced microstructural changes in oxygen irradiated Ti–6Al–4V

The change in microstructure and mechanical properties ofTi–6Al–4V alloy due to 160 MeV O6+ ion irradiation has been reported here. Detailed X-ray diffraction line profile analyses have been used to evaluate the microstructural parameters and characterize the nature of defects and their arrangements. The results indicate saturation of size of the coherent region, the dislocation density and its arrangement with dose, which points to an optimized final microstructure of irradiated material. This was also supported by the Vicker’s microhardness measurements. Electron back scattered diffraction study was used to assess the changes in microstructure in terms of the evolution of misorientation boundaries within the grains due to irradiation-induced defects. All the results support the radiation resistance nature of Ti–6Al–4V alloy. Finally, comparison has been made with earlier proton irradiation results, and the difference has been related to the nature of the displacement cascade produced by light and heavy ions.

Hadron Polarimetry for the Electron-Ion Collider

The Electron-Ion Collider (EIC) will be the first collider to use both polarized electron beams and polarized proton and light ion beams. It will therefore offer unique opportunities to study the structure of nucleons and to answer fundamental questions in QCD. The uncertainties on the polarization measurement translate directly into the uncertainties of final physics observables. Hence, a precise measurement of the hadron beam polarization and a good control of systematic uncertainties are critical for the success of the spin program at the EIC. Contrary to the case of electron beam polarimetry, which uses physical processes derived from first principles that allow a high precision extraction of the electron beam polarization, for hadron beams no such process is available. The currently best used methods rely on the process of elastic scattering in the Coulomb-Nuclear Interference (CNI) region, for which there are only effective models available. The experience from RHIC, the only existing polarized proton collider, will be detailed and the challenges of the measurements at the EIC will be addressed. In particular, measurements of the present RHIC polarimeters and simulations of the future EIC polarimeters will be presented.

The swarm Langmuir probe ion drift, density and effective mass (SLIDEM) product

Current methods for estimating ion density on Swarm rely on the assumption of 100% O + and no along-track ion velocity flows. These assumptions are routinely violated, particularly on the nightside and during high-latitude and polar cap traversals, compromising the accuracy of the measurements. The use of faceplate current data along with the Langmuir probe ion admittance measurements, and orbital-motion limited (OML) theory, make it possible to relax some of the assumptions inherent in current ESA Swarm density estimates. This further yields along-track ion drift and effective ion mass estimates. This paper describes the theoretical basis for estimating revised ion density, providing a new estimate for effective ion mass, as well as an alternative way of estimating along-track ion drift. The complete Swarm historical data set has been generated and validated using empirical models (International Reference Ionosphere, and an empirical electric field model), as well as ground-spacecraft conjunctions. Case studies and statistical results reveal clear geophysical signatures in the new product of light ions at low- and mid-latitudes and along-track ion drift at high latitudes, and their response to space weather.Graphical