Radiation Damage Research Articles

Objectives: Beta-emitting radionuclide therapy, exemplified by 177Lu-Oxodotreotide (Lutathera®), enables targeted treatment of neuroendocrine tumors by delivering β-radiation to tumor cells. However, the dose-dependent molecular mechanisms underlying cellular damage remain insufficiently characterized. This study aimed to investigate the phenotypic changes in IMR-32 human neuroblastoma cells following Lutathera exposure, with a focus on the dose-dependent relationship between radiation and cellular damage. Methods: IMR-32 cells were allocated to control, low- (0.05 MBq/mL), medium- (0.5 MBq/mL), and high-dose (5 MBq/mL) groups and treated with 177Lu-Oxodotreotide for 24 h. Flow cytometry was employed to assess cell viability, apoptosis, mitochondrial membrane potential, γ-H2AX expression (a marker of DNA damage), and proliferation. Results: Lutathera induced dose-dependent cytotoxic effects. Cell viability declined linearly with increasing dose (control: 100% vs. high-dose: 13.48%; r = -0.955, p < 0.001). Apoptosis was significantly elevated (control: 35.34% vs. high-dose: 88.12%; r = 0.999), accompanied by increased γ-H2AX levels (control: 5.26 × 104 vs. high-dose: 13.13 × 104; r = 0.930), indicating DNA double-strand breaks. Mitochondrial membrane potential decreased (control: 6.06 × 104 vs. high-dose: 46.27 × 104; r = 0.999), and proliferation was suppressed (control: 91.10 × 104 vs. high-dose: 103.84 × 104; r = 0.954), both showing strong dose correlations (p < 0.001). Conclusions: 177Lu-Oxodotreotide exerts dose-dependent cytotoxicity in IMR-32 cells via DNA damage, mitochondrial dysfunction, and apoptosis induction. These findings underscore the necessity of optimizing dosing regimens to balance therapeutic efficacy and safety in clinical settings, providing a foundation for personalized β-emitter therapies.

This paper examines the temperature dependence of the Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of protonated and deuterated n-hexacontane isotopologues. We observe a distinctive low-energy broadening in the characteristic C-H band with a change from cryogenic to ambient sample temperature. We model this temperature dependence with density functional theory simulations of the NEXAFS spectra, calculated for geometries obtained from abinitio molecular dynamics simulations. Our results show that thermally populated nuclear motion leads to peak broadening as the sample temperature increases but that this nuclear motion broadening has significant overlap with vibronic transitions. An improved understanding of thermal broadening mechanisms is essential for the use of NEXAFS spectroscopy for chemical microanalysis, particularly where cryogenic cooling is used to reduce radiation damage.

Boron neutron capture therapy (BNCT) is a progressive medical technique that combines the use of boron compounds and neutron radiation to preferentially destroy cancer cells while minimizing, but not entirely eliminating, damage to surrounding healthy tissues. This therapy relies on 10B, delivered via specific compounds, capturing neutrons and undergoing a nuclear reaction. This capture leads to the emission of high-energy alpha particles and lithium ions, which selectively damage the boron-loaded tumour cells, ultimately leading to their destruction. The key advantage of BNCT lies in its ability to deliver a highly localized and targeted treatment to cancer cells, and sparing healthy tissues from significant radiation damage due to the extremely short range of the reaction products. This makes it particularly suitable for treating certain types of tumours located in sensitive or critical areas where conventional radiation therapy is less effective or poses higher risks. In BNCT, the neutron source is a crucial component of the treatment process. Reactors and accelerators have traditionally been used as neutron sources in BNCT, while recent studies have also explored neutron generators. The success of BNCT depends on the development of effective boron delivery agents and optimized neutron sources, with recent advances in both areas expanding its clinical potential for treating challenging tumours. Recent advances in nanotechnology have introduced carbon dots as promising boron nanocarriers for BNCT. These carbon dots offer high biocompatibility and unique optical properties. Additionally, they have the ability to cross the blood-brain barrier, enabling targeted brain tumour delivery and imaging. Recent progress in molecular biology and imaging technologies is enhancing our knowledge of tumour characteristics and facilitating the development of boron compounds with greater selectivity for cancer cells. The present overview presents the historical development of the two primary BNCT components, the boron compound and neutron source, as well as their potential for future applications.

X-ray ptychography is an ultrahigh resolution imaging technique widely used in synchrotron radiation facilities. Its imaging performance relies on the quality of the acquired signals. However, the X-ray detectors used often suffer from signal loss due to sensor gaps, beamstops, defective pixels, overexposure, or other factors, resulting in degraded image quality. To suppress and compensate for the effects of signal loss, we proposed the known probe approach to partially recover the lost signals and introduced the high probe divergence strategy by investigating the effects of probe divergence on reconstruction quality under signal loss conditions. Both simulation and experiment results show that high probe divergence can effectively suppress the impact of signal loss on reconstruction quality while using a known probe as the initial probe for reconstruction can largely recover missing signals in Fourier space, resulting in a much better image than using a guessed initial probe. These strategies allow for high-quality imaging in the presence of signal loss without secondary data acquisition, significantly improving experimental efficiency and reducing radiation damage compared to previous strategies.

Abstract Accurate predictions of hydrogen isotope/tritium inventory in tungsten (W), used as a plasma-facing material in fusion reactors, can reduce the uncertainty associated with the self-sustaining fuel cycle. It is well-established that displacement damage generally enhances deuterium (D) retention in W, whereas helium (He) typically reduces it. However, the synergistic interaction between these two factors on D retention in W remains poorly understood. This study investigates the combined influence of displacement damage and plasma-implanted He on D retention in W, with focus on their dependence on D-induced blistering. High-energy (3.5 MeV) Fe13+ irradiations were conducted at 300 K to introduce displacement damage (0.1 dpa) in W. Low-energy (60 eV) He plasma exposure was then carried out at 600 K to generate a He-rich layer at the near surface of both pristine and Fe-irradiated samples. Subsequently, the samples were exposed to D plasma at 500 K, with the ion energy set to 38 eV. The results show that displacement damage increases D retention at low fluences (5 × 1024–1 × 1025 D m−2), but slightly decreases retention at higher fluences (3 × 1025–5 × 1025 D m−2). The impact of He on D retention in W is competitive, depending on the level of irradiation damage. In cases with minimal D-induced blistering (area ratio &lt;13%), the trapping effect dominates, with He-induced defects acting as strong D traps, leading to increased D retention. However, in highly damaged W, where high-density defects are induced by displacement damage or severe surface blistering (area ratio &gt;33%), the diffusion barrier effect of He-rich layer outweighs the trapping effect, leading to decreased D retention. The combined effect of displacement damage and He increases D retention at low D fluences and decreases it at high D fluences, with the magnitude of these changes deviating from a simple linear addition of their individual effects, indicating a complex, non-linear interaction.

Radiation therapy (RT) is essential for treating thoracic malignancies but often causes significant lung damage. FLASH‐RT, an ultra‐high dose rate irradiation technique, shows potential in reducing radiation‐induced lung injury (RILI) while maintaining tumor control. However, the underlying immune mechanisms remain poorly understood. This study investigates the immune and cellular responses to FLASH‐RT versus conventional dose rate (CONV) RT during the early phase of RILI. Using single‐cell RNA sequencing (scRNA‐seq), a dynamic landscape of the lung microenvironment is pictured during RILI within one‐week post‐irradiation. The analysis reveals that FLASH‐RT induces a more immediate but transient cellular response, while CONV‐RT causes sustained inflammation. FLASH irradiation significantly reduces neutrophil infiltration compared to CONV irradiation, particularly within the pro‐inflammatory Ccrl2+ subset. FLASH irradiation also triggers stronger activation of CD4+ CD40L+ Th cells, which are critical for regulating immune responses and balancing inflammation. Moreover, FLASH irradiation attenuates pro‐inflammatory activation and intercellular signaling of Mefv⁺ monocytes, thereby restraining excessive macrophage‐driven inflammation. Additionally, FLASH irradiation enhances TGF‐β signaling and epithelial‐mesenchymal transition (EMT) in alveolar type 1 (AT1) cells, promoting tissue repair. These findings highlight FLASH‐RT's superior immune modulation and reparative potential, providing valuable insights into its clinical application for minimizing radiation damage and enhancing lung recovery.

The recovery of radiation damage induced by 231-MeV xenon ions with varying fluence (from 5 × 1011 to 2 × 1014 cm−2) in α-Al2O3 (corundum) single crystals has been studied by means of isochronal thermal annealing of radiation-induced optical absorption (RIOA). The integral of elementary Gaussians (product of RIOA spectrum decomposition) OK has been considered as a concentration measure of relevant oxygen-related Frenkel defects (neutral and charged interstitial-vacancy pairs, F-H, F+-H−). The annealing kinetics of these four ion-induced point lattice defects has been modelled in terms of diffusion-controlled bimolecular recombination reactions and compared with those carried out earlier for the case of corundum irradiation by fast neutrons. The changes in the parameters of interstitial (mobile component in the recombination process) annealing kinetics—activation energy E and pre-exponential factor X—in ion-irradiated crystals are considered.

ABSTRACTThis study presents a classification model for nanoscale polymer characterization, utilizing low‐loss spectral data obtained through scanning transmission electron microscopy combined with electron energy‐loss spectroscopy. To enhance interpretability, spectral features are extracted via mixed Gaussian model fitting, where each Gaussian peak corresponds to a specific chemical bond state, facilitating the identification of key descriptors. These features enable effective clustering of seven standard polymers, achieving clear statistical separation based on four principal features. Furthermore, the extracted features are employed to visualize the progression of electron irradiation damage within an adequate data space. Feature changes under varying irradiation conditions are significantly correlated with alterations in the summed spectra. This methodology holds promise for advancing qualitative analyses of polymer alloys without electron staining, allowing detailed investigations into local denaturation and the presence of reaction layers. With the expansion of standard datasets, this approach offers a robust framework for characterizing and understanding polymer behavior at the nanoscale.

The low fluence proton radiation damage effects on the CMOS image sensor have been investigated, with a focus on its suitability for utilization in environments characterized by low fluence radiation exposure. The 10 MeV proton irradiation experiments are carried out at the EN Tandem Van De Graaff accelerator within the State Key Laboratory of Nuclear Physics and Technology at Peking University. Pre – and post-irradiation assessments of the CMOS image sensor encompassed evaluation of dark field parameters and bright field parameters, including random telegraph noise, mean dark signal, dark signal non-uniformity, hot pixels, and conversion gain. Analysis of the research findings reveals that proton irradiation leads to an increase in the mean dark signal, dark signal non-uniformity, and hot pixels of the CMOS image sensor, resulting in two-level, three-level, and multi-level random telegraph signal noise. Moreover, prolonged integration time exacerbates the observable effects of irradiation damage. Besides, there is no significant alteration in the conversion gain of the CMOS image sensor after proton irradiation. Drawing upon both experimental observations and theoretical simulations, it is inferred that the predominant mechanism underlying the damage induced by low fluence 10 MeV proton radiation is displacement damage.

Low-energy-electron emission from resonant Auger final states via intermolecular Coulombic decay (RA-ICD) has previously been described as a promising scenario for controlling radiation damage for medical purposes, but it has so far only been observed in prototypical atomic and molecular van der Waals dimers and clusters. Here, we report the experimental observation of RA-ICD in an aqueous solution. We show that for solvated Ca2+ ions, the emission can be very efficiently controlled by tuning the photon energy of exciting X-rays to inner-shell resonances of the ions. Our results provide the next step from demonstrating RA-ICD in relatively simple prototype systems to understanding the relevance and potential applications of ICD in real-life scenarios.

Ion interactions with molecular structures give insights into physicochemical processes in the cosmos, radiation damage, plasma, combustion, and biomass conversion reactions. At the atomic scale, these interactions lead to excitation, ionization, and dissociation of the molecular components of structures found across all these environments. Furan, cyclic aromatic ether (C4H4O), serves as a gas-phase deoxyribose analog and is crucial for understanding key pathways in renewable biomass conversion, as its derivatives are versatile molecules from lignocellulosic biomass degradation. Therefore, collisions of H3+ and C+ ions with gas-phase furan molecules were investigated in the 50–1000 eV energy range, exploiting collision-induced emission spectroscopy. High-resolution fragmentation spectra measured at 1000 eV for both cations reveal similar structures, with C+ collisions resulting in more significant furan fragmentation. Relative cross-sections for product formation were measured for H3+ + C4H4O collisions. Possible collisional processes and fragmentation pathways in furan are discussed. These results are compared with those for tetrahydrofuran and pyridine to illustrate how the type and charge of the projectile influence neutral fragmentation in heterocyclic molecules.

Radiation damage that can be caused to humans through exposure and ingestion (incorporation) of radioactive substances depends primarily on the amount and type of radiation and radioactive substances ingested. To exclude the possibility of radiation damage through the ingestion of radioactive substances, the maximum permissible concentrations (MPC) should be monitored as far as possible. This concept defines the limit values of the activity concentration of food products, drinking water and general consumption, after being exposed to radioactive contamination, which within a certain period of consumption does not cause serious damage to the population and people conducting emergency and rescue activities.

Radon gas, the predominant source of natural occurring radioactive substances is released by natural decay of uranium in the ground. Its half-life is 3.823 days and it can penetrate soils and rocks, contaminating surface and ground water sources. Ingestion (oral) and inhalation leads to a build-up of its daughters 218Po and 214Po in the lungs, whose high-energy alpha and gamma radiation damage cells. This research work aimed to evaluate the health hazards associated with 222Rn in some selected drinking water sources from Jibia Town, Katsina State, Nigeria. Twenty water samples from three different water sources were analyzed using liquid scintillation counter (Model Tri-Carb-LSA1000) situated at the Centre for Energy Research and Training of ABU Zaria. The corresponding annual effective doses due to ingestion and inhalation of 222Rn were also estimated. The mean activities concentrations of radon for surface, well and borehole water sources were 1.80±0.01BqL-1, 5.99±0.02 BqL-1 and 7.97±0.04 BqL-1 respectively, with overall mean value of 5.21±0.03 Bq/L. Similarly, the estimated mean annual effective dose due to inhalation and ingestion of radon were13.14±0.9 µSv/y (for all ages) and 37.95±2.5 µSv/y, 57.08±3.8 µSv/y and 66.59±4.4 µSv/y for adults, children and infants, respectively. Based on the achieved results, the specific activity concentrations of the radon and the estimated annual effective doses due to ingestion and inhalation of 222Rn were all found to be below the World average value of 10Bq/L set by WHO (2011) and recommended limit of 100µSv/y set by WHO (2011), respectively. Hence the radon concentrations were found to pose non-significant hazard to the populace from the drinking water sources.

Radiation damage significantly impacts the performance of silicon tracking detectors in Large Hadron Collider (LHC) experiments such as ATLAS and CMS, with signal reduction being the most critical effect. Adjusting sensor bias voltage and detection thresholds can help mitigate these effects, but generating simulated data that accurately mirror the performance evolution with the accumulation of luminosity, hence fluence, is crucial. The ATLAS collaboration has developed and implemented algorithms to correct simulated Monte Carlo (MC) events for radiation damage effects, achieving impressive agreement between collision data and simulated events. In preparation for the high-luminosity phase (HL-LHC), the demand for a faster ATLAS MC production algorithm becomes imperative due to escalating particle hit rates, imposing stringent constraints on available computing resources. This article outlines the philosophy behind the new algorithm, its implementation strategy, and the essential components involved. The results from closure tests indicate that the events simulated using the new algorithm agree with fully simulated events at the level of few %. The first tests on computing performance show that the new algorithm is as fast as it is when no radiation damage corrections are applied.

The LHCb experiment at CERN has been upgraded for the Run 3 operation of the Large Hadron Collider (LHC). A new concept of tracking detector based on Scintillating Fibres (SciFi) read out with multichannel silicon photomultipliers (SiPMs) was installed during its upgrade. One of the main challenges the SciFi tracker will face during the Run 4 operation of the LHC is the higher radiation environment due to fast neutrons, where the SiPMs are located. To cope with the increase in radiation, cryogenic cooling with liquid nitrogen is being investigated as a possible solution to mitigate the performance degradation of the SiPMs induced by radiation damage. Thus, a detailed performance study of different layouts of SiPM arrays produced by Fondazione Bruno Kessler (FBK) and Hamamatsu Photonics K.K. is being carried out. These SiPMs have been designed to operate at cryogenic temperatures. Several SiPMs have been tested in a dedicated cryogenic setup down to 100 K. Key performance parameters such as breakdown voltage, dark count rate, photon detection efficiency, gain and direct cross-talk are characterized as a function of the temperature. The main results of this study are going to be presented here.

TPS3648 Background: Indoleamine 2,3-dioxygenase 1 (IDO1) metabolizes tryptophan along the kynurenine pathway and is recognized as a potent suppressor of tumor reactive immunity. Epacadostat is an orally active, potent and selective inhibitor of IDO1. In preclinical studies, IDO1 was found to promote resistance to radiation in rectal cancer, irrespective of microsatellite instability (MSI) status. IDO1 inhibition with epacadostat improved tumor radiosensitivity by relieving immune suppression and augmenting radiation-induced apoptosis while protecting the normal intestine from radiation damage. In a phase 1 trial, 17 patients were enrolled from 4/2019 to 8/2023. Epacadostat in combination with short-course radiation therapy (SCRT) and CAPOX was well-tolerated and the recommended phase 2 dose (RP2D) of epacadostat was determined to be 400 mg BID. An NCI supported Phase 2 trial is ongoing to further evaluate the promising disease responses reported in the dose escalation phase. Methods: This phase 2 multicenter, open-label trial includes treatment and biomarker cohorts. In the treatment cohort, epacadostat at 400 mg BID will be administered concurrently with SCRT followed by epacadostat monotherapy until 1 day prior to neoadjuvant chemotherapy, followed by standard-of-care (SOC) neoadjuvant chemotherapy and, ultimately, surgical resection or non-operative management (NOM). Biomarker cohort enrollment will commence at completion of treatment cohort accrual. Enrolled patients will be treated with SOC SCRT followed by SOC neoadjuvant chemotherapy and surgical resection or NOM. Eligible patients must be a treatment-naïve, newly diagnosed, pathologically confirmed, locally advanced rectal cancer (defined by 8 th edition AJCC stage 2 or 3, or stage 1 not eligible for sphincter-sparing surgery) with plans to proceed with neoadjuvant SCRT and chemotherapy. The primary endpoint is the neoadjuvant rectal (NAR) score. Secondary endpoints are pathologic complete response (pCR) rate, complete clinical response (cCR) rate and progression-free survival (PFS). Exploratory endpoints are pharmacodynamics, PDX and organoid generation, identification of molecular predictors of response and resistance, correlation of radiographic and pathologic response and effect of treatment on patient quality of life. We aim to enroll 27 patients in the treatment cohort and 10 in the biomarker cohort. Clinical Trial Registration: NCT03516708 .

The ATLAS inner detector will be completely replaced to cope with the increased occupancy and radiation damage that will be posed by the High Luminosity phase of the Large Hadron Collider. The new all-silicon Inner Tracker will consist of pixel sensors in the innermost part. They will be realized using different silicon sensor technologies and will be read out with ITkPixV2 ASICs. Their connection is realized by bump bonding. n-in-p planar hybrid modules 100 µm and 150 µm thick will instrument the four outer layers of the pixel detector. Due to their radiation hardness, 3D sensors will be installed in the innermost layer, where a fluence up to 2.0 × 1016 neq/cm2 is expected. Their production is distributed among different vendors, and the pre-production sensors from each vendor are progressively being tested before and after irradiation with test beams. The most recent results will be presented here.

This paper presents a study of the radiation hardness of the hadronic Tile Calorimeter of the ATLAS experiment in the LHC Run 2. Both the plastic scintillators constituting the detector active media and the wavelength-shifting optical fibres collecting the scintillation light into the photodetector readout are elements susceptible to radiation damage. The dedicated calibration and monitoring systems of the detector (caesium radioactive sources, laser and minimum bias integrator) allow to assess the response of these optical components. Data collected with these systems between 2015 and 2018 are analysed to measure the degradation of the optical instrumentation across Run 2. Moreover, a simulation of the total ionising dose in the calorimeter is employed to study and model the degradation profile as a function of the exposure conditions, both integrated dose and dose rate. The measurement of the relative light output loss in Run 2 is presented and extrapolations to future scenarios are drawn based on current data. The impact of radiation damage on the cell response uniformity is also analysed.

New insights into radiation damage in additively manufactured alloy 718

We have been developing a CIGS detector for particle detection with high radiation tolerance. We irradiated the CIGS detector with a 132Xe54+ ion beam, delivering a total ionizing dose (TID) of 0.6 MGy at the HIMAC, and confirmed the recovery of leakage current and collected charge from radiation damage with heat annealing. To investigate higher radiation tolerance of the CIGS semiconductor, we irradiated CIGS solar cells with a 70 MeV proton beam with a non-ionizing energy loss (NIEL) for 1016neq· MeV/cm2 at the RARiS. The VIn and InCu defects created by 70 MeV proton irradiation were observed by deep level transient spectroscopy (DLTS). During thermal annealing at around 100°C, the Cu+ and V- Cu ions are excited to react with defects. These ions interact with VIn and InCu defects, creating electrical neutrality: 2Cu+ + V2- In → Cu2VIn and 2V- In + In2+ Cu → 2VIn InCu. By these reaction process, it is confirmed that both VIn and InCu defects were reduced by the thermal annealing at 130°C for two hours.