Alpha Particles Research Articles

First-in-human study of 225actinium mti-201 (225Ac-MTI-201) in metastatic uveal melanoma (UM).

TPS9612 Background: Prognosis in metastatic uveal melanoma (UM) has historically been poor approximating 1 year from diagnosis. Tebentafusp is the only approved systemic agent for HLA-A*02:01 positive metastatic UM, and novel therapies are needed. The melanocortin-1 receptor (MC1R) receptor is highly expressed in UM with limited expression in normal tissues. Actinium-225 (225Ac) is an alpha particle emitting radionuclide ideal for targeted ligand binding due to high linear energy transfer and limited free path (<100 µm) in tissue. We developed a novel MC1R targeted radiopharmaceutical 225Ac-MTI-201, and demonstrated high biostability, affinity, MC1R-specific cytotoxicity with defined dosimetry and pharmacokinetics in pre-clinical studies (1). Murine efficacy studies of UM showed significant delay of tumor growth and improved survival compared to controls. Methods: This is a single institution first-in-human phase I study (NCT05496686) of 225Ac-MTI-201 in metastatic UM. The primary objective is to determine the safety of a single intravenous dose of 225Ac-MTI-201 relative to radioactivity dose. Secondary endpoints include 1) pharmacokinetics (PK) and clearance of 225Ac-MTI-201, 2) objective response rate and duration, progression-free survival, and overall survival in metastatic UM. Salient eligibility criteria include: 1) age ≥18 years; 2) histologically confirmed metastatic UM with progression after at least 1 prior line of therapy; 3) measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1; 4) Eastern Cooperative Oncology Group performance status of ≤1; 5) adequate marrow, renal and hepatic function; 6) no more than 25% of bone marrow treated with prior radiotherapy. Patients will receive a single dose of 225Ac-MTI-201 under appropriate guidelines and precautions for administration of radiopharmaceuticals. Pre-injection and post-injection PK sampling at defined intervals are undertaken. There are 12 dose levels for 225Ac-MTI-201 being investigated ranging from 4.7 microcurie (µCi) to 1327 µCi. Dose escalation is done using a modified continual re-assessment method with a cohort size of one based on dose limiting toxicity (DLT) assessment within 28 days of drug administration using CTCAE v5.0. Definitions of DLT include G4 neutropenia or febrile neutropenia, G4 thrombocytopenia or G3 thrombocytopenia with clinically significant bleeding, > G3 non-hematological toxicity with selected exceptions, laboratory abnormalities that satisfy Hy’s law, or any death not related to underlying disease or extraneous cause. Response assessments are undertaken with cross-sectional imaging every 8 weeks in year 1, and every 12 weeks in year 2. This study is currently open for enrollment. Dose levels 1-4 have been completed without DLT. 1. Tafreshi, J Nucl Med 2019. Clinical trial information: NCT05496686 .

Low energy alpha particles dose mapping with a combination of CR-39 detector and a high resolution flatbed scanner

The potential of a combination of the well-known CR-39 detector and a high-resolution flatbed scanner for low energy alpha particles dose mapping is investigated. The CR-39 detectors were irradiated with perpendicular incident 4 MeV alpha particles of doses 0.009, 0.018, 0.033, 0.051, 0.067, 0.134, and 0.164 Gy, thereafter, etched in 6.25 N NaOH at 70 °C. The CR-39 detectors were scanned with Canon CanScan 9000F Mark II of spatial resolution of 9600 dpi and color depth of 48 bit. The measurements reveal that the pixel values for different color channels are correlated linearly with 4 MeV alpha particles dose at the etching times of 2 h, 3 h, and 4 h. For blue channel, the maximum sensitivity was −53178 ± 1463 pixel value/Gy at etching time of 4 h, compared to −15290 ± 2004 pixel value/Gy, and −42255 ± 840 pixel value/Gy at 2 h and 3 h respectively, the negative sign indicates the pixel values decrease as the 4 MeV alpha particles dose increases. While for etching times, 5 h and 6 h, the pixel values decrease exponentially as the 4 MeV alpha particles dose increases. For prolonged etching time, the pixel values are non-monotonic function of alpha particles dose. The optical density was evaluated as a function of etching time (removal thickness) of CR-39 irradiated with different doses. For 0.009 Gy, and 0.018 Gy doses of alpha particles, the optical density is linearly correlated with the etching time; for other doses, the optical density is not a monotonic function of the etching time. These new findings pave the way to use the combination of the CR-39 detector and high-resolution flatbed scanner for dose mapping of alpha particles and heavy ions over large-scale areas, applying etching conditions for each particle type and corresponding energy, that produce maximum sensitivity and linearity.

Measurements of low-energy, re-entrant albedo protons by the HEPD-01 space-borne detector

Cosmic rays’ interactions with the residual atmosphere surrounding the Earth produce a variety of particles, like electrons, positrons, protons, anti-protons, and Helium nuclei that can be observed below the local geomagnetic cutoff. In this work, we present new measurements of downward-going, albedo proton fluxes with kinetic energy in the range ∼40–∼250 MeV, performed by the High-Energy Particle Detector (HEPD-01) on board of the China Seismo-Electromagnetic Satellite - CSES-01 - at an altitude of ∼500 km. Employing a dedicated trajectory-tracing simulation routine, the protons collected by HEPD-01 are classified into quasi-trapped (QT), long lifetime (≳10 s) particles concentrating in the equatorial region of the Earth, and un-trapped (UT), distributed at all latitudes; the latter includes both precipitating short lifetime particles (UTS) and pseudo-trapped long lifetime (UTL) populations, abundant in the so-called penumbra regions. The temporal trend of re-entrant protons between 2018 and 2022 is also reported, assessing the stability of such population during the data-taking period of HEPD-01; this highlights their independence from the long-term modulating effect of the solar activity.

Data on Stark Broadening of N VI Spectral Lines

Data on Stark broadening parameters, spectral line widths, and shifts for 15 multiplets of N VI, whose spectral lines are broadened by collisions with electrons, protons, alpha particles (He III) and B III, B IV, B V and B VI ions, are presented. They have been calculated using the semiclassical perturbation theory, for temperatures from 50,000 K to 2,000,000 K, and perturber densities from 1016 cm−3 up to 1024 cm−3. The data for e, p and He III are of particular interest for the analysis and modelling of atmospheres of hot and dense stars, as, e.g., white dwarfs, and for investigation of their spectra, and data for boron ions are used for analysis and modelling of laser-driven plasma in proton–boron fusion research.

"Solar Alpha Particle Radiation Increases Human Mortality – An Example from the Malignant Melanoma Mortality in the Europe and Mediterranean"

"Solar Alpha Particle Radiation Increases Human Mortality – An Example from the Malignant Melanoma Mortality in the Europe and Mediterranean"

Enhancing gamma and neutron radiation shielding efficiency of LDPE/PVC polymers using cobalt, aluminum, and magnesium oxide fillers

A procedure for creating and assessing LDPE/PVC polymers using Co, Al, and Mg oxides as fillers for use as radiation shielding material was conducted. The SEM/EDX equipment was utilized for elemental analysis and mapping in order to visually represent the morphology of the produced polymers. The characterizations indicate that the MgCo2O4 particles possess an irregular and tiny morphology, displaying a spherical form with an average diameter of less than 100 nm. In addition, the Al2CoO4 particles are characterized as being aggregated, diminutive, and exhibiting a spherical morphology, with an average diameter of less than 150 nm. The current study involved experimental investigation, simulation using FLUKA-MC code, and theoretical calculations using Phy-X-PSD code to examine the radiological properties of the shielding material. The results depend on several factors, including the half-value layer (HVL), the effective atomic number (Zeff), the effective electron number (Neff), the effective conductivity (Ceff), the exposure buildup factor (EBF), the energy-absorption buildup factor (EABF), and the fast neutron macroscopic removal cross-section (FNRC). The SR-NIEL-7 platform has been utilized to compute the mass-stopping power for protons (H+) and alpha particles (He++) based on their kinetic energy. The experimental findings indicate that the density of LDPE/PVC filled with MgCo2O4 is greater than that of Al2CoO4. Furthermore, polymer filled with MgCo2O4 exhibits higher values for MAC, LAC, and FNRCs than Al2CoO4 filler. The measured LAC and MAC conform to the simulated values.

Heavy ions and alpha particles irradiation impact on III-V broken-gap gate-all-around TFET

This report deals with the impact of radiation on III-V and Si gate-all-around tunnel field effect transistors (GAA TFET). The highly energetic particles (HEPs) such as heavy ions and alpha particles are allowed to strike the device at several locations along the channel to determine the sensitive location of the device. Once the sensitive location is determined, then the device is irradiated to different energies of heavy ions and alpha particles. Further, to get a proximate match as a practically exposed device, the device has been irradiated to several incident angles. Before analyzing the device's behaviour, the models used for the analysis are calibrated with the transfer characteristics of an experimentally published report on III-V GAA TFET. Thereafter, analysis of charge collection, transient current, hole generation in the channel, and different incident angles are analyzed. Finally, it is concluded that III-V GAA TFET shows better immunity towards different incident angles under a radiation environment when compared to Si GAA TFET.

Concentrations of radon and other alpha emitters in biological samples of smokers and non-smokers

Concentrations of radon and other alpha emitters in biological samples of smokers and non-smokers

Preclinical Evaluation of Biodistribution and Toxicity of [211At]PSMA-5 in Mice and Primates for the Targeted Alpha Therapy against Prostate Cancer.

Astatine (211At) is a cyclotron-produced alpha emitter with a physical half-life of 7.2 h. In our previous study, the 211At-labeled prostate-specific membrane antigen (PSMA) compound ([211At]PSMA-5) exhibited excellent tumor growth suppression in a xenograft model. We conducted preclinical biodistribution and toxicity studies for the first-in-human clinical trial. [211At]PSMA-5 was administered to both normal male ICR mice (n = 85) and cynomolgus monkeys (n = 2). The mice were divided into four groups for the toxicity study: 5 MBq/kg, 12 MBq/kg, 35 MBq/kg, and vehicle control, with follow-ups at 1 day (n = 10 per group) and 14 days (n = 5 per group). Monkeys were observed 24 h post-administration of [211At]PSMA-5 (9 MBq/kg). Blood tests and histopathological examinations were performed at the end of the observation period. Blood tests in mice indicated no significant myelosuppression or renal dysfunction. However, the monkeys displayed mild leukopenia 24 h post-administration. Despite the high accumulation in the kidneys and thyroid, histological analysis revealed no abnormalities. On day 1, dose-dependent single-cell necrosis/apoptosis was observed in the salivary glands of mice and intestinal tracts of both mice and monkeys. Additionally, tingible body macrophages in the spleen and lymph nodes indicated phagocytosis of apoptotic B lymphocytes. Cortical lymphopenia (2/10) in the thymus and a decrease in the bone marrow cells (9/10) were observed in the 35 MBq/kg group in mice. These changes were transient, with no irreversible toxicity observed in mice 14 days post-administration. This study identified no severe toxicities associated with [211At]PSMA-5, highlighting its potential as a next-generation targeted alpha therapy for prostate cancer. The sustainable production of 211At using a cyclotron supports its applicability for clinical use.

In vitro and in vivo evaluation of a tetrazine-conjugated poly-L-lysine effector molecule labeled with astatine-211

BackgroundA significant challenge in cancer therapy lies in eradicating hidden disseminated tumor cells. Within Nuclear Medicine, Targeted Alpha Therapy is a promising approach for cancer treatment tackling disseminated cancer. As tumor size decreases, alpha-particles gain prominence due to their high Linear Energy Transfer (LET) and short path length. Among alpha-particle emitters, 211At stands out with its 7.2 hour half-life and 100% alpha emission decay. However, optimizing the pharmacokinetics of radiopharmaceuticals with short lived radionuclides such as 211At is pivotal, and in this regard, pretargeting is a valuable tool. This method involves priming the tumor with a modified monoclonal antibody capable of binding both the tumor antigen and the radiolabeled carrier, termed the “effector molecule. This smaller, faster-clearing molecule improves efficacy. Utilizing the Diels Alder click reaction between Tetrazine (Tz) and Trans-cyclooctene (TCO), the Tz-substituted effector molecule combines seamlessly with the TCO-modified antibody. This study aims to evaluate the in vivo biodistribution of two Poly-L-Lysine-based effector molecule sizes (10 and 21 kDa), labelled with 211At, and the in vitro binding of the most favorable polymer size, in order to optimize the pretargeted radioimmunotherapy with 211At.ResultsIn vivo results favor the smaller polymer’s biodistribution pattern over the larger one, which accumulates in organs like the liver and spleen. This is especially evident when comparing the biodistribution of the smaller polymer to a directly labelled monoclonal antibody. The smaller variant also shows rapid and efficient binding to SKOV-3 cells preloaded with TCO-modified Trastuzumab in vitro, emphasizing its potential. Both polymer sizes showed equal or better in vivo stability of the astatine-carbon bond compared to a monoclonal antibody labelled with the same prosthetic group.ConclusionsOverall, the small Poly-L-Lysine-based effector molecule (10 kDa) holds the most promise for future research, exhibiting significantly lower uptake in the kidneys and spleen compared to the larger effector (21 kDa) while maintaining an in vivo stability of the astatine-carbon bond comparable to or better than intact antibodies. A proof of concept in vitro cell study demonstrates rapid reaction between the small astatinated effector and a TCO-labelled antibody, indicating the potential of this novel Poly-L-Lysine-based pretargeting system for further investigation in an in vivo tumor model.

Comparative analysis of heavy ions and alpha particles impact on gate-all-around TFETs and gate-all-around MOSFETs

The single-event-transient (SET) effect due to heavy ions and alpha particles irradiation on n-type gate-all-around tunnel field effect transistor (GAA TFET) and n-type gate-all-around MOSFET (GAA MOSFET) has been carried out. Due to differences in carrier injection mechanisms, the generated electron-hole pairs (EHPs) due to high-energy particles (HEPs) act differently on the device. In addition, the impact of HEPs (i.e., heavy ions and alpha particles) on several locations along the channel are analyzed followed by the analysis of different energies of heavy ions and alpha particles irradiation on the device. Further, the impact of varying striking angles of HEPs on the device is also analyzed to get a close match as practically exposed device characteristic. Finally, the bipolar gain of the device has been analyzed which shows GAA TFET device has more immunity toward heavy ions strike and weak immunity toward alpha particle strikes when compared to the GAA MOSFET counterpart.

Chromosomal damage, gene expression and alternative transcription in human lymphocytes exposed to mixed ionizing radiation as encountered in space

Astronauts travelling in space will be exposed to mixed beams of particle radiation and photons. Exposure limits that correspond to defined cancer risk are calculated by multiplying absorbed doses by a radiation-type specific quality factor that reflects the biological effectiveness of the particle without considering possible interaction with photons. We have shown previously that alpha radiation and X-rays may interact resulting in synergistic DNA damage responses in human peripheral blood lymphocytes but the level of intra-individual variability was high. In order to assess the variability and validate the synergism, blood from two male donors was drawn at 9 time points during 3 seasons of the year and exposed to 0–2 Gy of X-rays, alpha particles or 1:1 mixture of both (half the dose each). DNA damage response was quantified by chromosomal aberrations and by mRNA levels of 3 radiation-responsive genes FDXR, CDKN1A and MDM2 measured 24 h post exposure. The quality of response in terms of differential expression of alternative transcripts was assessed by using two primer pairs per gene. A consistently higher than expected effect of mixed beams was found in both donors for chromosomal aberrations and gene expression with some seasonal variability for the latter. No synergy was detected for alternative transcription.

Investigation of dosimetric characteristics of radiochromic film in response to alpha particles emitted from Americium-241.

In radiotherapy, it is essential to deliver prescribed doses to tumors while minimizing damage to surrounding healthy tissue. Accurate measurements of absorbed dose are required for this purpose. Gafchromic® external beam therapy (EBT) radiochromic films have been widely used in radiotherapy. While the dosimetric characteristics of the EBT3 model film have been extensively studied for photon and charged particle beams (protons, electrons, and carbon ions), little research has been done on -particle dosimetry. -emitting radionuclides have gained popularity in cancer treatment due to their high linear energy transfer, short range in tissue, and ability to spare surrounding organs at risk, thereby delivering a more localized dose distribution to the tumor. Therefore, a dose-calibration film protocol for -particles isrequired. This study aimed to develop a dose-calibration protocol for the -particle emitting radionuclide 241Am, using Monte Carlo (MC) simulations and measurements with unlaminated EBT3films. In this study, a MC-based user code was developed using the Geant4 simulation toolkit to model and simulate an 241Am source and an unlaminated EBT3 film. Two simulations were performed: one with voxelized geometries of the EBT3 active volume composition and the other using water. The dose rate was calculated within a region of interest in the voxelized geometries. Unlaminated EBT3 film pieces were irradiated with the 241Am source at various exposure times inside a black box. Film irradiations were compared to a 6-MV photon beam from a Varian TrueBeam machine. The simulated dose rate was used to convert the exposure times into absorbed doses to water, describing a radiochromic-film-based reference dosimetry protocol for -particles. The irradiated films were scanned and through an in-house Python script, the normalized pixel values from the green-color channel of scanned film images wereanalyzed. The 241Am energy spectra obtained from the simulations were in good agreement with IAEA and NIST databases, having differences 0.516% for the emitted -rays and produced characteristic x-rays and 0.006% for the -particles. Due to the short range of -particles, there was no energy deposition in the voxels outside the active 241Am source region projected onto the film surface. Thus, the total dose rate within the voxels covering the source was 0.847 0.003 Gy/min within the sensitive layer of the film (LiPCDA) and 0.847 0.004 Gy/min in water, indicating that the active volume can be considered water equivalent for the 241Am beam quality. A novel approach was employed in -film dosimetry using an exponential fit for the green channel, which showed promising results by reducing the uncertainty in dose estimation within 5%. Although the statistical analysis did not reveal significant differences between the 6-MV photon beam and the calibration curves, the dose-response curves exhibited the expected behavior. The developed MC user code simulated the experimental setup for -dosimetry using radiochromic film with acceptable uncertainty. Unlaminated EBT3 film is suitable for the dosimetry of -radiation at low doses and can be used in conjunction with other unlaminated GafChromic® films for quality assurance and researchpurposes.

Новая модель эволюции Вселенной

Experiments and properties of low-energy nuclear reactions are presented.The existence of new ground states in the hydrogen atom, in the helium ion, and other hydrogen-like atoms located in a strong magnetic field at the appearance of third spatial oscillatory quantum number is shown. On the example of a transhelium atom, the possibility of pairing atomic electrons into an orthoboson is considered. The possibility of generating strong and ultra-strong magnetic fields in cosmic absolute plasma in the Photon era has been demonstrated, in which electrons recombine with protons and helium nuclei with the transition to transhydrogen and transhelium atoms. Transatoms combine into transmolecules and enter into multinuclear, radiation-free, low-energy reactions.The time of constant, natural nucleosynthesis has begun.The nucleosynthesis of carbon, nitrogen and oxygen atoms, when they were overwhelmingly surrounded by hydrogen atoms, led after the era of Recombination to intensive organic and bioorganic synthesis, which resulted in the origin of life and filling the entire Universe with that life. Low-energy nuclear reactions that occur in stars have been demonstrated.The possibility of natural nucleosynthesis occurring on Earth is shown.

Characterization of Surface α-Particle Radiation, Internal Traceability and Simulation of Typical Tin Spheres

Surface α-particle emissivity testing and spectral characterization of two leaded tin spheres (Sn10%Pb90%, Sn63%Pb37%) and one lead-free tin sphere (Sn96.5%Ag3.0%Cu0.5%, SAC305) were carried out. The results show that Sn10%Pb90% Sn spheres have the highest α-particle emissivity; Sn63%Pb37% Sn spheres are the next highest, which is an order of magnitude lower than the α-particle emissivity of Sn10%Pb90% Sn spheres; and SAC305 Sn spheres have the lowest emissivity, which is reduced by about 55.6% compared to the emissivity of Sn63%Pb37% Sn spheres. All three types of tin spheres, after purification treatment, achieved the grade of ultra-low alpha particle emissivity (<0.002 α/(cm2·h)). The internal radionuclide traceability of the tin sphere, combined with the energy spectrum, reveals that the emission spectrum of the tin sphere exhibits an obvious “single peak” characteristic, with the peak energy in the interval of 5 MeV~5.5 MeV. Comparative analyses revealed that 210Po is the main nuclide that produces alpha particles, and 210Po originates from the decay of 210Pb. Further Monte Carlo simulations show that α-particles with energies greater than 4.1 MeV in the measured energy spectrum all come from the contribution of radionuclides within 5 μm of the surface layer of the tin sphere, which accounts for 60% of the total radioactivity. Combining the experimental and simulation results, it is found that the internal radionuclides of the tin sphere are characterized by more surface layer and less internal layer. The above results are of great significance for the establishment of α-particle mitigation methods for tin spheres.

Velocity-space distribution function of fast ions in a sawtoothing plasma

This study explores the influence of sawtooth oscillations on the velocity space distribution of fast ions in tokamak plasma discharges. The relevant Fokker–Planck equation for fast ions is solved analytically. Two distinct effects arising from the temperature drop associated with a sawtooth crash and their impact on the distribution function of fast ions are considered. The first effect involves the modulation of the fusion alpha particle source on the timescale of the sawtooth period, linked to the drop in fusion yield resulting from the sawtooth temperature relaxations. The second effect is tied to the increase of the slowing-down time during the sawtooth ramp, causing particles born later in the sawtooth cycle to experience reduced slowing down compared to those born right after the crash, creating an accumulation-like mechanism at higher energies. In regimes where the sawtooth period is shorter than the fast ion slowing-down time, the combined influence of these effects gives rise to fast ion distribution functions that transiently exhibit positive slopes in velocity space.

The structural, optical, electrical and radiation shielding properties of Co-doped ZnO thin films

Co:ZnO thin films are promising due to the similar ionic radii of cobalt and ZnO, and their potential for carrier spin injection, transfer, and detection. This study aims to investigate the structural, optical, electrical, and radiation shielding properties of Co-doped zinc oxide (Co:ZnO) thin films for potential applications in various fields such as semiconductors, solar cells, spintronics, and radiation shielding. The effect of commercially available Cobalt acetate tetrahydrate and Cobalt complex (Co with conjugated NN ligand) as cobalt additives on the synthesis of ZnO thin films is compared, aiming to discern their respective impacts. The dopants are incorporated in 2, 4, and 6 wt%, employing the sol-gel spin coating method.Applying cobalt complex additive as Co precursor resulted in ZnO:Co films with a superior enhancement of the electronic band gap of 2.84–3.00 eV compared to cobalt acetate precursor (2.62–2.84 eV). With the introduction of Cobalt, there is a notable change in the electrical conductivity, showcasing a decrease from 1.5x10−7 to 2.11x10−10 (S/cm). Also, radiation shielding parameters were experimentally measured in the energy range of 186.1–1764.5 keV within the scope of gamma ray spectral analysis. Exposure buildup factors (EBF) in the energy range of 15–15,000 keV were calculated up to 1–40 mean free path (mfp). Mass stopping power (MSP) and projected range values (PR) for nuclear safety applications were calculated for protons and alpha particles using the SRIM code. Thin film thicknesses were determined by using Lambert-Beer law. It was observed that the thin film thicknesses obtained from gamma spectrometry (2.090–2.628 μm) and SEM (2.157–2.725 μm) were compatible with each other.

Reduction of electrostatic turbulence in a quasi-helically symmetric stellarator via critical gradient optimization

We present a stellarator configuration optimized for a large threshold (‘critical gradient’) for the onset of the ion temperature gradient (ITG) driven mode, which achieves the largest critical gradient we have seen in any stellarator. Above this threshold, gyrokinetic simulations show that the configuration has low turbulence levels over an experimentally relevant range of the drive strength. The applied optimization seeks to maximize the drift curvature, leading to enhanced local-shear stabilization of toroidal ITG modes, and the associated turbulence. These benefits are combined with excellent quasi-symmetry, yielding low neoclassical transport and vanishingly small alpha particle losses. Analysis of the resulting configuration suggests a trade-off between magnetohydrodynamic (MHD) and ITG stability, as the new configuration possesses a vacuum magnetic hill.

Apatite–Wollastonite (AW) glass ceramic doped with B2O3: Synthesis, structure, SEM, hardness, XRD, and neutron/charged particle attenuation properties

In the study, the influence of doping apatite-wollastonite (AW) glass-ceramics (GCs) with B2O3 on the structural, physical, microstructural, and light and heavy particle interaction properties is presented. Using the solid-state reaction and the cold isostatic press method, pristine AW, 10 wt% (AW-B10), and 20 wt% (AW-B20) B2O3-doped AW GCs were prepared. The prepared GCs were subject to structural, chemical compositional, and surface morphological investigation through standard experimental processes. Furthermore, the neutron (fast and thermal) and charged radiation (electron, proton, alpha, and carbon ion) interactional parameters of the GCs were obtained through standard theoretical models and software. The density of AW (2.91 gcm−3) increases to about 2.957 and 2.986 gcm−3 as B2O3 increases to 10 and 20 wt%, respectively. The presence of boron oxide supported the wollastonite phase to remain glass and suppressed crystallisation in the AW GCs. Doping AW with B2O3 improved the interaction probabilities of the GCs with fast and thermal neutrons, electrons, protons, alpha particles, and carbon ions. B-rich AW is thus potentially useful as a target material in human tissues for boron neutron capture therapy for the management of cancer and tumours, isolating or shielding specific tissues in ion beam therapy processes, and other techniques that require the exposure of human tissues to irradiation.

Durolon® polymer as a nuclear track detector: Characterization by chemical etching

This paper presents the properties of alpha particle tracks in a polymer, known as Durolon®. The study involves measurements of the time-dependent evolution of etch pit diameters and areal densities for low-energy alpha particles under various etching conditions, including different temperatures and solutions. A time-dependent model was successfully employed to describe the etch pit growth rates. Additionally, optical absorption and Raman spectroscopy techniques were applied to the samples under investigation, complementing the traditional results obtained through optical microscopy. The suitability of Durolon® polymer as a nuclear track detector is discussed based on the results obtained from the aforementioned complementary techniques. In summary, this research represents a critical step toward establishing Durolon® polymer as a viable nuclear track detector.