Light Ions Research Articles

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 Russianlanguage 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.

Experimental investigation of beam-ion losses induced by magnetic perturbations using the light ion beam probe technique in the ASDEX Upgrade tokamak

The impact of externally applied magnetic perturbations (MPs) on fast-ion losses has been investigated by means of the light ion beam probe (LIBP) technique in the ASDEX Upgrade tokamak. The LIBP technique allows to experimentally infer the fast-ion orbit displacement induced by MPs via first-orbit losses using scintillator based fast-ion loss detector (FILD) measurements. The fast-ion orbit displacement against different applied MP spectra has been studied. These shots were conducted in ELM mitigated H-mode plasmas. A rigid rotation of the MP coils was applied with a frequency of 1 Hz, with an n = 2 configuration and changing the differential phase between the upper and lower set of coils (ΔΦul) on a shot-to-shot basis. Beam sources Q7 (tangential) and Q8 (radial) were used to probe different fast-ion orbits with FILD1. The measured fast-ion orbit displacement ranges from 3 to 20 mm approximately, and no qualitative difference is observed between ions from beam sources Q7 and Q8. The minimum is found for a ΔΦul ∼ 50°, which is shifted with respect to the minimum of the plasma boundary displacement, found at ΔΦul ∼ 0°. A first attempt to validate the orbit following code ASCOT—including the plasma response calculated with the MARS-F code—against these experimental measurements is performed. While the dependence of the first-orbit fast-ion displacement with ΔΦul does not match the experimental measurements, these simulations do capture other features such as the order of magnitude of the orbit displacement and the importance of the toroidal spectrum of the applied perturbation.

Spot-scanning hadron arc (SHArc) therapy: A proof of concept using single- and multi-ion strategies with helium, carbon, oxygen, and neon ions.

To present particle arc therapy treatments using single and multi-ion therapy optimization strategies with helium (4 He), carbon (12 C), oxygen (16 O), and neon (20 Ne) ion beams. An optimization procedure and workflow were devised for spot-scanning hadron arc therapy (SHArc) treatment planning in the PRECISE (PaRticle thErapy using single and Combined Ion optimization StratEgies) treatment planning system (TPS). Physical and biological beam models were developed for helium, carbon, oxygen, and neon ions via FLUKA MC simulation. SHArc treatments were optimized using both single-ion (12 C, 16 O, or 20 Ne) and multi-ion therapy (16 O+4 He or 20 Ne+4 He) applying variable relative biological effectiveness (RBE) modeling using a modified microdosimetric kinetic model (mMKM) with (α/β)x values of 2, 5, and 3.1Gy, respectively, for glioblastoma, pancreatic adenocarcinoma, and prostate adenocarcinoma patient cases. Dose, effective dose, linear energy transfer (LET), and RBE were computed with the GPU-accelerated dose engine FRoG and dosimetric/biophysical attributes were evaluated in the context of conventional particle and photon-based therapies (e.g., volumetric modulated arc therapy [VMAT]). All SHArc plans met the target optimization goals (3GyRBE) and demonstrated increased target conformity and substantially lower low-dose bath to surrounding normal tissues than VMAT. SHArc plans using a singleion species (12 C, 16 O, or 20 Ne) exhibited favorable LET distributions with the highest-LET components centralized in the target volume, with values ranging from ∼80-170keV/μm, ∼130-220keV/μm, and ∼180-350keV/μm for 12 C, 16 O, or 20 Ne, respectively, exceeding mean target LET of conventional particle therapy (12 C:∼55, 16 O:∼75 20 Ne:∼95keV/μm). Multi-ion therapy with SHArc delivery (SHArcMIT ) provided a similar level of target LET enhancement as SHArc compared to conventional planning, however, with additional benefits of homogenous physical dose and RBE distributions. Here, we demonstrate that arc delivery of light and heavy ion beams, using either a single-ion species (12 C, 16 O, or 20 Ne) or combining two ions in a single fraction (16 O+4 He or 20 Ne+4 He) affords enhanced physical and biological distributions (e.g., LET) compared with conventional delivery with photons or particle beams. SHArc marks the first single- and multi-ion arc therapy treatment optimization approach using light and heavy ions.

Isolation, purification, and characterization of novel melanin from the submerged fermentation of Rhizobium radiobacter

In this study, a novel water-insoluble bacterial melanin was first isolated and purified from the fermentation culture of Gram-negative bacterial Rhizobium radiobacter ATCC 1333 through the thermal acid-alkali treatment. The highest extracellular melanin production was 3.46 ± 0.07 g·L−1 when the initial glutamic acid concentration was 10 g·L−1. The molecular weight of the purified bacterial melanin (TPBM) was 686 g/mol. The molecular formula (C34H30N4O12) and chemical structure were defined based on FT-IR, MALDI-TOF/MS, Py–GC/MS NMR (1H and 13C), and elemental analyses. Furthermore, UV–vis spectroscopy results indicated that TPBM showed maximum absorption at around 222 nm. TPBM was easily soluble in alkaline solutions, but hardly-soluble in aqueous and majority of the organic solvents. In addition, TPBM was stable to temperature, light, reducing agent, and most metal ions. However, TPBM could be bleached when subjected to the action of oxidants and precipitated with FeCl3 and AgNO3. TPBM (50 µg·mL−1) possessed high DPPH free radical (89.74% ± 1.10%) and hydroxyl scavenging properties (84.12% ± 1.31%). Finally, TPBM displayed potential anti-bacterial properties against E. coli, S. aureus, A. baumanii, and M. albican. These results provided a theoretical basis for the later development and utilization of TPBM.

Exclusive Z0 production in ep and eA collisions at high energies

In this work the $k_{\perp}$-factorization formalism is applied to compute the exclusive $Z^0$ boson photoproduction in $ep$ and $eA$ collisions. The study is also extended to $pp$ and $AA$ processes. The nuclear effects are investigated considering heavy and light ions. Analytical models for the unintegrated gluon distribution are taken into account and the corresponding theoretical uncertainty is quantified. The analysis is done for electron-ion collisions at the Large Hadron-Electron Collider (LHeC), its high-energy upgrade (HE-LHeC) and at the Future Circular Collider (FCC) in lepton-hadron mode. Additionally, ultra-peripheral heavy ion collisions at future runs of the Large Hadron Collider (LHC) and at the FCC (hadron-hadron mode) are also considered.

Ultra-intense laser-accelerated ion beams for high-gain inertial fusion: the effect of the ion mass on the beam properties

This paper presents the results of detailed numerical studies of the properties of ion beams generated by a laser from targets with various atomic numbers under conditions relevant for ion fast ignition (IFI) of inertial fusion. The interaction of a 200 kJ 1 ps infrared (1.05 μm) laser with Li, C, Al, Ti, Cu and CH2 flat targets with the same areal mass density was numerically simulated using an advanced 2D3V particle-in-cell code. For each target, a set of ion beam characteristics important for IFI was determined. A detailed quantitative comparison of the IFI-relevant parameters of Li, C, Al, Ti and Cu ion beams and the proton beam (from the CH2 target) was made. The laser-accelerated Cu ion beam was found to achieve significantly higher values of beam intensity, fluence and ‘useful’ energy (for IFI), having a smaller angular divergence and a narrower energy spectrum than the beam of light ions or protons. Thus, it is shown for the first time that laser-accelerated heavy ion beams can achieve IFI-relevant parameters higher than light ion or proton beams and can potentially meet IFI requirements.

Advantages to use graphene oxide thin targets in forward ion acceleration using fs lasers

AbstractAdvanced targets based on thin foils of graphene oxide (GO) covered by metallic layers show many advantages with respect to others because permit high proton and light ion acceleration using high intensity pulsed lasers in Target‐Normal Sheath‐Acceleration (TNSA) regime. GO foils contain parallel micrometric graphene sheets, have low density, show high penetration, and low scattering by energetic electrons accelerated by laser, inducing electron channelling effects. They contain high concentrations of hydrogen, water, and functional oxygen groups, can be realized as thin films with high mechanical resistance, and show high photon absorbance for laser beams. In this work, we present experimental results obtained by our research group using thin GO targets covered by thin gold films, prepared in our laboratories. Advanced targets have been irradiated in TNSA regime with 40 fs laser pulses at the intensity of the order of 1019 W/cm2, using a laser spot of about 10 microns diameter, permitting to accelerate ions at energies of the order of 6 MeV per charge state. The electric field of ion acceleration can be increased by optimizing the irradiation conditions and the GO and Au film thicknesses. The novel findings of this work concern the high forward ion acceleration obtained using thin targets containing GO which induces the effect of electron channelling and production of high‐density forward plasma. The plasma diagnostics are developed with fast SiC semiconductor detectors connected in time‐of‐flight (TOF) configuration. The fast semiconductor detector response permits to optimize the ion acceleration conditions by changing the distance of the laser focus with respect to the target surface, the incidence angle and the laser parameters.

Calculating the fragmentation process in quadrupole ion traps

The present theoretical study calculates the consequences of an ion dissociating in a quadrupole field, describing both 3D and linear ion traps. The dissociation induces a change in q-stability parameter, resulting in fragment ions abruptly changing their trajectories. This includes a change in oscillation amplitude and mean-square velocity, i.e., effective collisional temperature. While the first one can lead to ions being lost to the electrodes, the latter one can be used to determine how likely fragment ions are to be further excited. During the collisional focusing process, ions can endure internal heating, just like during the injection process. The difference here is that fragment ions start this process with already elevated internal energies. The process is calculated by making use of the well-known phase-space ellipses. It is shown that fragment ions of lower m/z in average decrease their oscillation amplitude and are thus better trapped. Only very light ions close to the LMCO have a high chance of being lost. However, lighter fragment ions in average start with higher mean-square velocities than the precursor was assumed to need to have to induce dissociation, suggesting further collisional heating. Despite the harsh collisional environment m/z ratios close to the LMCO in average have to endure, a small percentage of these ions drastically decrease their oscillation amplitude, not requiring any collisional focusing. Fragment ions of higher m/z in average increase their oscillation amplitudes, however, their low velocities make further internal heating unlikely. The used calculations have been uploaded to Github: https://github.com/NeugebauerT/ion-trap.

Tailoring of magnetic anisotropy by ion irradiation for magnetic tunnel junction sensors

Magnetic Tunnel Junctions (MTJ) are employed in a range of technologies such as data storage, sensing, and so on due to their compact nature and high field sensitivity. In magnetic films and structures, ion irradiation is capable of modifying the crystal structure, phases and magnetic properties including magnetic anisotropy, which enables tunability of the sensing axis of devices such as MTJ sensors. Irradiation can also adjust the magnetic properties of specific layers without affecting the others, making it one of the most effective methods to post-process multi-layered devices. In this article we review the literature of light ion irradiation effects on MTJs and their component materials, focusing on the effects most relevant to MTJ sensors, such as magnetic anisotropy and magnetization. We first briefly review the effects of the ion-solid interaction, then discuss the causes of magnetic anisotropy, and lastly, we summarize the state of the field of ion-induced modification of magnetic properties in ferromagnetic thin films, antiferromagnetic structures, and MTJs.

Chromium adsorption using Sargassum filipendula algae waste from alginate extraction: Batch and fixed-bed column studies

Chromium is a toxic metal widely used in several industrial activities, being frequently found in industrial effluents. The presence of chromium in its soluble ionic form Cr(III) is related to health risks, damage to living beings and to the environment. In this work, the capture of Cr(III) using alginate extraction residue (RES) from the Sargassum filipendula algae was evaluated to investigate the adsorption properties of this waste material. The study steps included batch and continuous adsorption assays, characterizations, and desorption evaluation. The adsorbent residue was not submitted to pre-treatment steps. The investigation of chromium adsorption and the fluid dynamic study are presented in this work. The equilibrium and thermodynamic studies indicated that the uptake of Cr(III) by the RES occurred spontaneously, endothermic, and energetically favorable on a heterogeneous surface with energetically distinct sites, mainly by chemisorption. The Freundlich and Dubinin-Radushkevich, and pseudo-second order models showed better fit to the equilibrium and kinetic experimental data, respectively. In the continuous fixed-bed system, the breakthrough curves showed a smaller mass transfer zone under flow rate and Cr(III) inlet concentration conditions of 0.5 mL/min and 1.0 mmol/L, respectively. The low desorption percentages corroborate the chemical nature of the bonds involved in adsorption. The best result of 67.5% was obtained with the combined eluent of HCl and CaCl2, both at 1 mol/L. SEM and EDX analyzes showed that ion exchange is involved in the adsorptive process with a reduction in the amount of light ions (Na, Ca, Mg, and K) on the RES surface. The characterization analyzes indicated that hydroxyls are the main group involved in the adsorption of metal that occurred on the surface of the RES.

Controlling the Ion Transport Number in Solvent-in-Salt Solutions.

Solvent-in-salt (SIS) systems present promising materials for the next generation of energy storage applications. The ion dynamics is significantly different in these systems from that of ionic liquids and diluted salt solutions. In this study, we analyze the ion dynamics of two salts, Li-TFSI and Li-FSI, in highly concentrated aqueous and acetonitrile solutions. We performed high-frequency dielectric measurements covering the range of up to 50 GHz and molecular dynamics simulations. The analysis of the conductivity spectra provides the characteristic crossover time between individual charge rearrangements and the normal charge diffusion regime resulting in DC conductivity. Analysis revealed that the onset of normal charge diffusion occurs at the scale of ∼1.5-3.5 Å, comparable to the average distance between the ions. Based on the idea of momentum conservation, distinct ion correlations were estimated experimentally and computationally. The analysis revealed that cation-anion correlations can be suppressed by changing the solvent concentration in SIS systems, leading to an increase of the light ion (Li+ in our case) transport number. This discovery suggests a way for improving the light cation transport number in SIS systems by tuning the solvent concentration.

Rewritable acidochromic papers based on oxazolidine for anticounterfeiting and photosensing of polarity and pH of aqueous media

Oxazolidine is a new category of stimuli-chromic organic compounds with unique characteristics in response to polarity, pH changes, water, light, and metal ions that were well-known as solvatochromism, acidochromism, hydrochromism, photochromism, and ionochromism, respectively. Therefore, oxazolidine derivatives have been developed for their potential applications in chemosensors, anticounterfeiting, and rewritable hydrochromic papers. In this study, various oxazolidine derivatives containing hydroxyl and naphthalene substituted groups were synthesized by using two different indolenine compounds. The synthesized oxazolidine derivatives were used for investigation of solvatochromism in different solvents, and also acidochromism in various pHs by using UV–Vis and fluorescence spectroscopies. In addition, the oxazolidine derivatives were coated on cellulosic papers using a layer-by-layer strategy to develop rewritable acidochromic papers for printing of security tags on cellulosic papers by using acidic and alkaline solutions as water-based inks. Therefore, the developed rewritable acidochromic papers could be used as security papers.

The physicochemical properties and immunomodulatory activities of gardenia yellow pigment from gardenia fruit

• High temperature, acid, alkali, Fe 3+ , and ultraviolet radiation greatly affected the stability of gardenia yellow pigment (GYP). • GYP exhibited good antioxidant properties. • The immunomodulatory activity of GYP in RAW264.7 cells were confirmed. • GYP can be developed as a potential antioxidant and immunomodulator in functional foods. Gardenia yellow pigment (GYP) was isolated from Gardenia jasminoides fruit. GYP possess various beneficial biological activities, but its immunomodulatory activity remains incompletely known. In present study, we evaluated the stability of GYP at different temperature, light, pH, and metal ions firstly. The antioxidant capacity of GYP was then evaluated by 1, 1-Diphenyl-2-picrylhydrazyl radical (DPPH), 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Ferric ion reducing antioxidant power (FRAP), and Hydroxyl radicals. Finally, the immunomodulatory activities and underlying mechanism of GYP were determined using RAW264.7 cells. The results indicated that the stability of GYP was greatly affected by higher temperature (60–100 ℃), ultraviolet radiation, acid, alkali, and Fe 3+ . Furthermore, GYP exhibited strong antioxidant activity, and the IC 50 values of DPPH, ABTS, and Hydroxyl radicals were 0.44, 0.07, and 0.09 mg/mL, respectively. Meanwhile, FRAP value was 1.65 ± 0.04 mM FeSO 4 at the GYP concentration of 0.11 mg/mL. The cell experiment exhibited that GYP significantly enhanced the proliferation and phagocytosis of macrophages. It also increased the secretion of NO, TNF-α, IL-10, and COX-2, and promoted the activation of transcription factor (NF-κB) in RAW264.7 cells. Furthermore, GYP promoted the phosphorylation of P13K and Akt in RAW264.7 cells, indicating that GYP might exert its immunoregulatory effects through modulation of PI3K/Akt pathway. Overall, the results of this study suggest that GYP can be used as a natural antioxidant and immunomodulator in the fields of functional foods.

Modulating properties by light ion irradiation: From novel functional materials to semiconductor power devices

In this review, the application of light ion irradiation is discussed for tailoring novel functional materials and for improving the performance in SiC or Si based electrical power devices. The deep traps and electronic disorder produced by light ion irradiation can modify the electrical, magnetic, and optical properties of films (e.g., dilute ferromagnetic semiconductors and topological materials). Additionally, benefiting from the high reproducibility, precise manipulation of functional depth and density of defects, as well as the flexible patternability, the helium or proton ion irradiation has been successfully employed in improving the dynamic performance of SiC and Si based PiN diode power devices by reducing their majority carrier lifetime, although the static performance is sacrificed due to deep level traps. Such a trade-off has been regarded as the key point to compromise the static and dynamic performances of power devices. As a result, herein the light ion irradiation is highlighted in both exploring new physics and optimizing the performance in functional materials and electrical devices.

Pigment of Ceiba speciosa (A. St.-Hil.) Flowers: Separation, Extraction, Purification and Antioxidant Activity.

In this work, the extraction procedure of a natural pigment from the flower of Ceiba speciosa (A. St.-Hil.) was optimized by response surface methodology. It is the first time that the extraction of the flower pigment of C. speciosa (FPCS) has been reported, along with an evaluation of its stability and biological activity under various conditions, and an exploration of its potential use as a food additive and in medicine. Specifically, the effects of ethanol concentration, solid–liquid ratio, temperature and time on the extraction rate of FPCS were determined using a Box–Behnken design. The optimum extraction conditions for FPCS were 75% ethanol with a solid–liquid ratio of 1:75 mg/mL) at 66 °C for 39 min. The purification of FPCS using different macroporous resins showed that D101 performed best when the initial mass concentration of the injection solution was 1.50 mg/mL, resulting in a three-fold increase in color value. The yield of dry flowers was 9.75% of fresh petals and the FPCS extraction efficiency was 43.2%. The effects of light, solubility, pH, temperature, sweeteners, edible acids, redox agents, preservatives and metal ions on FPCS were also investigated. Furthermore, the characteristics of FPCS were determined by spectrophotometry at a specific wavelength using the Lambert–Beer law to correlate the mass of FPCS with its absorbance value. An acute toxicological test performed according to Horne’s method showed that FPCS is a non-toxic extract and thus may be used as a food additive or in other ingestible forms. Finally, western blotting showed that FPCS prevents lipopolysaccharide-induced hippocampal oxidative stress in mice. The study suggests that FPCS may function as an antioxidant with applications in the food, cosmetics and polymer industries.

Lanthanide extraction using a thiodiglycolamic acid extractant: effect of S-donor on lanthanide separation.

Liquid-liquid extraction of lanthanide (Ln) ions was investigated using N,N-dioctylthiodiglycolamic acid (DOTDGAA), which is a sulfur donor ligand with an amide group and a carboxyl group connected by a thioether chain. The extraction performance and selectivity of DOTDGAA for Ln ions were compared with those of N,N-dioctyldiglycolamic acid (DODGAA), which is also an oxygen donor ligand with a similar chemical structure, to assess the effect of the soft/hard donor atom on Ln separation. DOTDGAA quantitatively extracted all Ln ions while being selective toward the light and middle Ln ions, in contrast to the selectivity of DODGAA for heavier Ln ions. Slope analysis demonstrated that the Ln3+ transfer using DOTDGAA proceeded through a proton-exchange reaction, forming a 1:3 complex, Ln(DOTDGAA)3. The back-extraction of Ln ions from the extracting phase was successfully achieved under acidic conditions.

Highly enhanced ferroelectricity in HfO2-based ferroelectric thin film by light ion bombardment.

Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices requires integration of ferroelectric and semiconductor materials. The emergence of hafnium oxide (HfO2)-based ferroelectrics that are compatible with atomic-layer deposition has opened interesting and promising avenues of research. However, the origins of ferroelectricity and pathways to controlling it in HfO2 are still mysterious. We demonstrate that local helium (He) implantation can activate ferroelectricity in these materials. The possible competing mechanisms, including He ion-induced molar volume changes, vacancy redistribution, vacancy generation, and activation of vacancy mobility, are analyzed. These findings both reveal the origins of ferroelectricity in this system and open pathways for nanoengineered binary ferroelectrics.

Production of neutron deficient rare earth radionuclides by heavy ion activation

Abstract The attempts to produce neutron deficient radioisotopes of rare Earth elements by heavy ion activation are discussed in this review. The heavy ion induced reaction products have large atomic number difference with that of the target; therefore, radiochemical separation of no-carrier-added radio-lanthanides from the target matrix becomes easier. Heavy ion induced reactions also allow the production of rare Earth radionuclides from non-rare Earth target by tailor-made target-projectile combinations, and in those cases, radiochemical separations become even more easier. In general, the cross sections of heavy ion induced reactions are less than those of light charged particle induced reactions. However, some of the heavy ion induced reactions have comparable cross sections with those of light ion induced reactions. The range of heavy ions is also much smaller in the target matrix than that of lighter charged particles. These points hinder application of heavy ion induced reactions to produce radionuclides for nuclear medicine.

Nonlinear and supernonlinear ion-acoustic wave phenomena in an electron-positron-pair-ion quantum plasma

A four-component quantum plasma consisting of electrons, positrons, negative heavy ions and positive light ions is proposed in this work. The dynamics of nonlinear and supernonlinear ion-acoustic waves are studied in the framework of the Korteweg–de Vries (KdV) and modified Korteweg–de Vries (mKdV) equations which are derived employing the reductive perturbation technique. Using Galilean transformation these two evolution equations are transformed into planar dynamical systems. All possible phase portraits and corresponding small-amplitude Sagdeev's pseudopotential of these dynamical systems are presented graphically. The unique topology of phase portrait and a maxima in between two minimas in pseudopotential curves clearly establish quantum ion-acoustic superperiodic waves. Solitary, periodic and superperiodic wave solutions corresponding respectively to homoclinic, periodic and superperiodic orbits in phase portraits are obtained numerically and the influence of different parameters on these waves is observed. Further, various kinds of analytical wave solutions for the two evolution equations are discussed.

Collaboration: The Force That Makes the Impossible Possible

AbstractOver the last three decades, the landscape of cancer treatment with radiotherapy has never stopped improving. ENLIGHT – the European Network for Light Ion Hadron Therapy – has been an active participant in the huge changes that have taken place, in particular in Europe. At the end of the 90s when I arrived at CERN, it appeared clear that an improvement in communication, sharing and exchange, while keeping a common goal, was needed to bring together international experts from accelerator physics, imaging, medical physics, radiobiology and clinical medicine. ENLIGHT network was most aptly launched at CERN, since CERN is renowned as a place for global collaboration. The network has come a long way since the kick-off meeting at CERN in 2002 when only about 70 specialists from different disciplines took part and continues to grow and flourish with now over 1000 participants, accounting for over 100 institutions, from around 40 countries around the globe.