We demonstrate that secondary ions sputtered from a macrocapillary's inner surface by the primary beam induce premature saturation of the guiding field, hindering fast ion guiding. By suppressing secondary ion sputtering with grooved surfaces, we achieve a guiding-field potential difference exceeding 1 kV, 2 orders of magnitude larger than previously achieved in stable ion guiding. This enables stable guiding of a 20-keV/q O^{5+} beam at offset angles up to 15°, with transmitted ions retaining their initial energy and charge state. A self-consistent field model accurately reproduces these results, revealing that guiding performance relies on managing secondary ions and the channel's voltage tolerance, while remaining robust against beam fluctuations. This Letter paves the way for ionic fibers that, much like optical fibers for light, passively and adaptively control ion transport.

Energy-efficient separation of xylene isomers remains a long-standing challenge owing to their nearly identical physicochemical properties. Here we report a double-bowl, sandwich-type palladium molecular cage (Pd3L2) assembled from a bowl-shaped phosphangulene oxide ligand and (bpy)PdII (2,2′-bipyridine) centers, featuring a hydrophobic and shape-persistent cavity. Benefiting from precise size and shape complementarity, Pd3L2 exhibits exceptional selectivity for o-xylene (OX) over its isomers (m-xylene, MX; p-xylene, PX), enabling efficient separation from an equimolar OX/MX/PX mixture and affording OX with a purity of up to 90

Background: Dosimetric measurements in proton ultra-high dose rate (UHDR) radiotherapy (i.e., FLASH radiotherapy) remain highly challenging. Ionization chambers, as the gold standard for dose monitoring, hold significant potential for clinical application. However, systematic quality assurance methods with ionization chambers under ultra-high dose rate scenarios are still lacking. Purpose: This study aims to design a novel dose measurement system and evaluate its feasibility for FLASH proton therapy. Methods: A beam monitoring system based on a low-pressure ionization chamber (LPIC) was developed and comprehensively tested with UHDR proton beams. Performance assessments included energy dependence, dose and dose rate linearity, and the capability to measure beam profiles and depth dose distributions. Results: The results showed that the LPIC system exhibited minimal energy dependence. Reducing the chamber gas pressure effectively mitigated ion recombination compared while preserving excellent dose and dose rate linearity, with coefficients of determination (R2) exceeding 0.999 for all linear fits. For beam profile characterization, LPIC measurements demonstrated deviations were within 0.3 mm in spot position and 0.1 mm in spot size compared with GafchromicTM EBT3 film measurements. Combined with solid plate phantoms, LPIC accurately measured depth dose distributions of FLASH beams, achieving excellent agreement with reference data and yielding a gamma passing rate of 94.68% (1 mm, 1%). Conclusions: This study demonstrates the feasibility of LPIC-based dosimetry for proton FLASH beam characterization. While the current results support the potential of the approach for future FLASH QA workflows, further work is required to assess long-term stability, measurement uncertainties, and inter-system reproducibility. In addition, the extension of calibration or performance observed under conventional conditions to FLASH dose-rate conditions requires further dedicated validation.

Coordination-driven self-assembly provides a powerful tool for constructing chiral metal-organic cages with well-defined stereochemistry and function; however, enantiopure cages with high structural complexity remain rare, and their governing design principles are not yet well established. Here we report the synthesis of O -symmetric, face-capped Pd 6 L 8 octahedral cages assembled from bowl-shaped, helically chiral ligands with Pd II . Assembly of the racemic ligand afforded rac -Pd 6 L 8 as a pair of enantiomers, Pd 6 L P 8 and Pd 6 L M 8 , via narcissistic chiral self-sorting. Single-crystal X-ray diffraction (SC-XRD) and reduced density gradient (RDG) analysis demonstrated that the twelve interligand π–π stacking interactions provide main driving force for such chiral self-sorting. Enantiopure ligands also self-assembled with Pd II to give enantiopure Pd 6 L P 8 and Pd 6 L M 8 , that could be used for enantioselective recognition of BINOL-derived chiral phosphoric acids, with enantioselectivity proven by distinct binding constants, emission responses and 1 H NMR discrimination. This study demonstrates how interligand noncovalent interactions can be used to govern stereochemical outcomes in complex polyhedral cages formation and highlights their potential application in chiral sensing.

Particle radiotherapy offers unique physical and biological advantages over photon radiotherapy. However, it shows numerous uncertainties due to positioning errors, range straggling, incident particle errors, and other factors. Addressing and mitigating these uncertainties can lead to more precise treatment and reduce the unnecessary or excessive doses administered to patients. A critical approach to reducing uncertainties in treatment is the implementation of three-dimensional (3D) dosimetry. Thus, developing an independent technique for 3D dose reconstruction in patients during treatment delivery is crucial for particle therapy facilities. In this study, we aimed to develop a real-time 3D dosimetric imaging system for particle therapy to monitor the beam range and dose distribution in patients during particle therapy. A prototype of the imaging system was designed and evaluated using a beam monitoring system and dose engine (DoRT). The beam monitoring system was used to measure the parameters of a pencil beam in real-time during treatment, and DoRT was used to reconstruct the 3D dose distribution of the pencil beam in the target. We performed a functional evaluation of this prototype with carbon ions incident on a heavy-ion medical machine (HIMM) and compared the reconstructed dose distribution with those obtained from Monte Carlo calculations and film measurements. For the investigated zigzag-scanning delivery case, real-time dose reconstruction with 1 mm cubic voxels was achieved by this prototype, and with the reconstructed dose image updated every 46 ms. The reconstructed doses were benchmarked against Monte Carlo simulated results, where the average gamma index passing rate (3 mm, 3

Ion stopping in dense plasma is crucial for stellar evolution and fusion ignition. However, its behavior in the strong ion-plasma coupling regime beyond the linear limit has long remained elusive, due to formidable experimental challenges. Here we report the first experimental investigation of ion stopping at an unprecedented coupling parameter exceeding unity, achieved by sending laser-accelerated short-pulse and intense quasi-monoenergetic carbon ions (∼583 keV/u, C^5+) into a uniform, long-lived, well-characterized dense plasma target (T_e ≈ 17 eV, n_e ≈ 4×10^20 cm^-3). By simultaneously measuring ion energy loss and charge-state evolution, we eliminated key experimental ambiguities arising from charge-state determination. Our results clearly show a reduction in stopping power compared with predictions from standard linear dielectric response or binary collision models, and they agree well with the hybrid calculation of molecular dynamics with quantum corrections. The importance of nonlinear screening effects arising from many-body interactions and quantum effects due to the wave nature of electrons was demonstrated at strong coupling. This work establishes a definitive high-fidelity experimental benchmark for collisional dynamics in the strong-coupling regime. It offers critical insight for accurate modeling of energy transport in inertial confinement fusion and astrophysical plasmas.

BACKGROUND:Hypoxia significantly affects radiotherapy by increasing tumor radioresistance. High linear energy transfer radiation, such as carbon ion therapy, can help mitigate this issue. Carbon ion arc therapy offers the potential to increase LET in hypoxic tumor regions, offering a promising approach to improve treatment outcomes, but lacks robustness. PURPOSE:We introduced and quantitatively evaluated a new heavy ion therapy treatment strategy named LET bOost by heavy Particle Arc RaDiation (LEOPARD), which combines intensity-modulated particle therapy (IMPT) with spot-scanning hadron arc (SHArc) strategy. LEOPARD aims to increase dose and the dose-averaged linear energy transfer ( LET d ${\rm LET}_{\mathrm{d}}$ ) within the hypoxic target volume (HTV) while maintaining plan quality and robustness. IMPT and SHArcBoost are used as reference strategies for comparison. METHODS:A proof of concept for LEOPARD was realized on 15 head & neck cancer patients with an artificially contoured HTV generated from isotropic shrinking of the clinical target volume (CTV). The LEOPARD plans integrate a full arc field (0 ∘ $^\circ$ to 358 ∘ $^\circ$ , step = 2 ∘ $^\circ$ , 180 fields) delivering a boost dose to the HTV with additional IMPT fields(10 ∘ $^\circ$ and 170 ∘ $^\circ$ ) that simultaneously provide the prescribed dose to the CTV, combining both approaches in a unified treatment plan. To evaluate the potential of LEOPARD, we compared it to intensity modulated particle therapy dose boost plans (IMPTBoost) which included 2 IMPT fields (10 ∘ $^\circ$ and 170 ∘ $^\circ$ ) for CTV, with 2 identical fields added to boost dose in HTV, and SHArc-only boost plans (SHArcBoost) which used same arc fields as LEOPARD aimed at both CTV and HTV but without IMPT fields. Plans were evaluated for dosimetric accuracy, robustness, LET d ${\rm LET}_{\mathrm{d}}$ , and cell survival fraction considering the oxygen-enhancement ratio. Treatment delivery times were calculated using an in-house dynamic carbon ion arc therapy delivery simulator. RESULTS:LEOPARD combined treatment demonstrated a capacity to balance plan quality by mitigating the robustness issues inherent in SHArc plans while improving the LET distribution compared to IMPTBoost plans. Compared with SHArcBoost, LEOPARD showed higher mean D95 in the HTV (96.1% vs. 95.4%; p < 0.001 $p < 0.001$ ), lower mean D2 (113.2% vs. 117.0%; p < 0.001 $p < 0.001$ ) and HI (18.3% vs. 22.6%; p < 0.001 $p < 0.001$ ). Compared with IMPTBoost, mean LET d ${\rm LET}_{\mathrm{d}}$ 50 in the HTV increased by 16.9% ( p < 0.001 $p < 0.001$ ), and mean SF50 in the HTV reduced by 3.8% ( p < 0.001 $p < 0.001$ ). CONCLUSION:We developed a new treatment strategy-LEOPARD, which can generate higher LET d ${\rm LET}_{\mathrm{d}}$ in the HTV than IMPTBoost, while achieving better dose distribution and plan robustness compared to SHArcBoost. This work therefore indicates promising potential of LEOPARD for the treatment of hypoxic tumors.

Objective. In clinical proton therapy, patient-specific quality assurance (PSQA) is typically performed by using two-dimensional (2D) array detectors placed at two or three selected depths within a phantom. While this method is effective for basic verification, it lacks comprehensive spatial coverage and may miss dose delivery errors in the region with steep dose gradients. This study aims to develop and validate a novel three-dimensional (3D) dosimetry system (PlanDOSE) for full volumetric dose reconstruction from a single treatment delivery, improving the efficiency and accuracy of PSQA in pencil beam scanning (PBS) proton therapy. Approach. PlanDOSE reconstructs 3D dose distributions by real-time monitoring the proton pencil beam using a multi-layer ionization chamber (MLIC) and an integrated dose-position monitoring system (IDPMS). The system was calibrated in detail prior to use, including absolute monitor unit (MU) response, relative channel sensitivity, and water-equivalent thickness (WET) calibration. Its performance was evaluated for multiple intensity modulated proton therapy plans of varying complexities, which includes three standard proton cubes and three clinical plans (brain, lung, liver). Dose distributions reconstructed by PlanDOSE were compared with Eclipse treatment planning system calculations using gamma analysis (2 mm/2%, 10% threshold). Main results. Calibration results showed that PlanDOSE achieved absolute MU measurement errors within ±1%, and inter-channel correction significantly improved the response consistency of MLIC. WET calibration enabled accurate depth-dose curve measurements, with average errors between −1.07% and 2.34%. In dose reconstruction validation, PlanDOSE achieved average gamma passing rates of 98.53% for lateral, 95.40% for depth, and 96.85% for 3D dose distributions. Compared to traditional 2D-based QA dosimetry, PlanDOSE demonstrated higher spatial resolution and better dose fidelity, particularly in regions with steep gradients. Significance. PlanDOSE enables accurate, high-resolution 3D dose verification from a single treatment delivery, offering a more efficient and clinically informative alternative to conventional QA methods, and shows great potential for routine use in PSQA for PBS proton therapy.

Background: and Purpose: FLASH radiotherapy has aroused strong interest among researchers, but how to monitor dose in real time and lack of generally accepted ion correction model are one of the challenges. This study is based on previous research work, the dosimetric verification of FLASH ionization chamber was performed using a 200 keV electron beam irradiation platform at an ultra-high dose rate. At the same time, the finite element program is written to analyze and calculate the ion correction factor. In addition, the results are compared with the calculation results of Boag model. Methods: In this study, the pressure of the sensitive volume in the detector was adjusted to 16 mbar for the purpose of dosimetry of dose rates in excess of 100 Gy/s. In order to monitor the response of the detector, the beam frequency and pulse width were adjusted accordingly. However, due to the saturation effect of the ionization chamber, the processes of electron ion pair drift, attachment, recombination and diffusion in the sensitive volume were modelled on the basis of the relevant physical principles. Finally, the correction factor was calculated by the finite element analysis. Results: The experimental results demonstrate that the FLASH ionization chamber is capable of meeting the requirements of dose measurement and beam monitoring of the electron beam at ultra-high dose rates. Furthermore, the analytical model is able to more accurately describe the saturation effect and calculate the correction factor. Conclusion: In this paper, the method of reducing air pressure is employed for the purpose of monitoring the dose of ultra-high dose rate. Simultaneously, the finite element method was employed to analyze the physical process of electron-ion pairs within the chamber and to calculate the ion correction factor analytically. A comparison with the Boag model indicates that the proposed approach is effective. However, the results exhibit a certain degree of divergence from experimental outcomes. This discrepancy may be attributed to the influence of the input parameters, which require further calibration to enhance the accuracy and the robustness of the model.

Carbon ions therapy has become a globally prevalent treatment due to its highly efficiency in tumor eradication by including DNA double-strand breaks within the Bragg peak region, while avoiding the need for invasive surgery. A pre-treatment assessment using X-ray technology is necessary to draw the tumor morphology for carbon ions impinging. However, metal implants adjacent to tumor area often generate heavy artifacts during CT scans, compromising accurate tumor evaluation. We propose a radiography method utilizing high-energy carbon ion beams, which exhibit stronger penetration and density sensitivity compared to X-ray. In this study, we investigate the important physical properties of marginal range (where Bragg peaks location) radiography by using high energy carbon ions beams incidence different morphology targets at the Heavy Ion Research Facility in Lanzhou (HIRFL). By modulating the beam energy, the detailed interior structures of targets are visualized slice-by-layer. The results demonstrated that the marked copper plate and the CPU targets achieved density resolution of about 1.6 % at 10.9 g/cm2 and spatial resolution of 500 mu m. For the ball-point pen, the sequence radiographs of different depth features are presented. An agreement is found between the Geant4 simulation and the experimental results. Both low-Z and high-Z material components in the ball-point pen are distinctly differentiated, and a three-dimensional visual target is reconstructed. Through in vitro experiment, we validate the important physical properties of marginal range radiography and extending its application to tumor cases with high Z metal implants. The excellent resolution power is expected to solve the tumor morphology caused by metal artifacts in CIRT treatment. Such combination of marginal range radiography with Bragg peak cancer therapy provides a unique solution for the future development of carbon ion theranostic.

A distorted low-symmetry Eu4L4 tetrahedral cage was fabricated through the self-assembly of europium ions and C3-symmetric bowl-shaped ligands containing a phosphangulene core. X-ray crystallography confirmed its unique architecture, featuring significant structural distortion and solvent-accessible coordination sites. This cage showcases exceptional luminescence-based sensitivity for formaldehyde detection compared to other analogs, achieving an impressive detection limit of 19.4 ppb.

FLASH radiotherapy (RT) reduces the level of irradiation damage to normal tissue by utilizing an ultra-high dose rate to deliver the dose into the tumor target area in millisecond-order time. The ultra-high dose rate (>= 40 Gy/s) renders existing online dose monitors largely ineffective or dose-rate dependent. In this study, the dose distribution based on a 9 MeV ultra-high dose rate electron beam FLASH irradiation platform was investigated using Gafchromic EBT3 film, and its flatness deviation within +/- 5 % and symmetry deviation within +/- 3 % meets the standard requirements. We also explored the saturation effect observed in ionization chambers (IC) used for online monitoring by reducing the sensitive volume of the chamber and its air pressure. Real-time dose monitoring was successfully achieved with the electron beam at a source skin distance (SSD) of 100 cm and a dose rate of 250 Gy/s, demonstrating a linearity deviation within +/- 2 %. The IC correction factor was calculated according to the IAEA TRS-398 standard. In conclusion, this study successfully established quality assurance for electron beam irradiation at ultra-high dose rates using Gafchromic EBT3 film and enabled effective online dose monitoring. This work provides a dosimetric foundation for future scientific research and clinical applications of FLASH RT.

Achieving upconverted circularly polarized luminescence (UCCPL) in rare-earth complexes has long been considered a formidable challenge due to the and the complex stereochemistry of lanthanide cenwith AAAA or AAAA metal stereochemistry were constructed by assembling C2-symmetric chiral ligands with Ln3+ ions. Under 980 nm excitation, UC emissions from Eu3+and Sm3+centers in the heterometallic (Yb/Eu)4(LR/S)6 and (Yb/Sm)4(LR/S)6 assemblies were realized via multimeric triplet-mediated cooperative sensitization pathways in solution at room temperature. Furthermore, the integration of photon UC with chirality-enabled UCCPL to be achieved in the rare-earth supramolecular system for the first time. This work introduces a novel approach to designing UCCPL materials and opens new avenues for the development of chiral rare-earth functional materials.

Beam monitoring and evaluation are very important to boron neutron capture therapy (BNCT), and a variety of detectors have been developed for these applications. In this study, a method of position sensitive neutron detector based on evaporated solid neutron conversion layer is proposed and designed, and the structure design and working gas optimization of the detector are carried out by Monte Carlo method. The related hardware design of readout electronics for neutron detector is completed, and the electronic performance test is carried out. The results show that the thickness of the neutron conversion layer is the best when the thickness of the neutron conversion layer is 2 mu m. At the same time, the aluminum layer coated with 2 mu m after the neutron conversion layer can effectively reduce the most probable angle of the emitted particles, and Ar: CO2 (90: 10) is used as the working gas. The front-end readout electronics can meet the bipolar signal processing of 64 channels in the dynamic range of 120 fC similar to 10 pC at the sampling frequency of 1-100 MHz. The set of electronic system has high integration, low noise, low power, and can quickly process multi-channel signals. The integral nonlinearity is less than 1.5 %, which can meet the requirements of real-time online monitoring neutron detectors of BNCT. It is evident that this ionization-based neutron detector with multichannel and high counting rate capability has great development prospects dose monitoring and evaluation applications in BNCT.

BACKGROUND:Efficient and accurate measurement methods to acquire three-dimensional (3D) dose distributions of proton pencil beams are currently lacking. Conventional dosimetric techniques demonstrate limitations in achieving spatially complete and metrologically precise rapid 3D dose measurements, which reduces the accuracy of beam modeling in treatment planning system (TPS) and the efficiency of routine quality assurance (QA) practices. PURPOSE:To develop an efficient and accurate dosimetry system for 3D dose distribution characterization of proton pencil beams. METHODS:We developed a newly designed 3D dosimetry system (PBDOSEmini), which integrates two multi-strip ionization chambers (MSICs), a servo motor system, and a sealed water tank. To achieve rapid and precise measurement of 3D dose distributions, this system employs continuous dynamic scanning combined with dual-detector synchronized measurement technology. In a clinical proton beamline, the spatial and dosimetric performances of the PBDOSEmini were characterized and compared with Monte Carlo simulation results, as well as measurements using Gafchromic films (EBT3) and a commercial water phantom system (IBA Blue Phantom2). RESULTS:The PBDOSEmini demonstrated a linearity of R2 > 0.999 for both dose and dose rate within the clinical range. The 2D dose comparison to the film measurement resulted in a position deviation less than 0.5 mm and a size deviation of beam spot less than 3%. A 3D dose distribution measured within 30 seconds was compared to simulation results and showed an average gamma passing rate of 96.13% (2 mm/2%). Comparative analysis indicates acceptable agreement between the measured depth-dose distributions from PBDOSEmini and Blue Phantom2. Repeatability verification showed that the median relative standard deviation (RSD) of all data points was 0.17% (IQR = 0.04%). CONCLUSION:The newly designed PBDOSEmini demonstrates excellent spatial and dosimetric performance, making it highly suitable for providing fundamental data for TPS, routine QA practices, and other clinical applications in proton therapy.

The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing a challenge for dose monitoring.In addition,there is no generally accepted ion correction model for dosimetry in FLASH radiotherapy,making it crucial to monitor the dose at ultra-high dose rates accurately and in real time.In this study,the air pressure of the ionization chamber was reduced to perform real-time beam monitoring,and a Faraday cup was used for cali-bration for active dosimetry.To study the saturation effect of the ionization chamber,the drift,attachment,recombination,and diffusion processes of the electron-ion pairs were modeled using finite-element analysis based on physical phenomenological principles,and the correction factor was calculated.The experimental results showed that the FLASH ionization chamber measures good dose linearity at a dose rate of approximately 0.2 Gy/s.When the air pressure of the chamber was adjusted to 10 mbar,the response of the FLASH ionization chamber was linear at a dose rate of approximately 50 Gy/s,with the residuals within 2％.Furthermore,by using physical phenomenology to resolve the process of electron-ion pair motion in the sensitive volume of the ionization chamber,the analytical model better describes the saturation effect of carbon ions at ultra-high dose rates.The maximum deviation in the calculated correction factor is less than 10％.We studied the saturation effect in dose measurement,achieving accurate and fast dose and profile position measurement across different dose rates in a wide range based on the Heavy Ion Research Facility in Lanzhou.

The FLASH effect of carbon ion therapy has recently attracted significant attention from the scientific community. However, the radiobiological mechanism of the effect and the exact therapeutic conditions are still under investigation. Therefore, the dosimetry accuracy is critical for testing hypotheses about the effect and quantifying FLASH Radiotherapy. In this paper, the FLASH ionization chamber at low-pressure was designed, and its dose rate dependence was verified with the Faraday cup. In addition, the dose response was tested under the air pressure of the ionization chamber of 10 mbar, 80 mbar and 845 mbar, respectively. The results showed that when the pressure was 10 mbar, the dose linearity was verified and calibrated at the dose rate of ∼50 Gy s-1, and the residuals were less than 2%. In conclusion, the FLASH ionization chamber is a promising instrument for online dose monitoring.

The accurate measurement of three-dimensional (3D) dose distribution of carbon-ion pencil beams in water is crucial for regular quality assurance (QA) practice. Although ionization chambers scanned in a water tank is conventionally used for this purpose, these measuring methods are time-consuming and labor-intensive. In addition, the beam of Heavy Ion Medical Machine (HIMM) changes continuously in each extracted duration, these methods cannot obtain the accurate 3D dose distribution. To solve these problems, an integrated system (PBDOSE) is conceived and established, which employs multi-strip ionization chambers (MSICs) to measure 2D lateral profile dose distributions. The lateral profile dose distribution in the context of various depths is measured by a mobile MSIC and normalized by the measurement of a reference MSIC to reduce the effect of beam instability. On this basis, a 3D dose distribution is created by stacking those profiles in depth direction. By conducting a single depth scan within 3 minutes on HIMM, information such as the 3D dose distribution, lateral contour images, the Bragg curve, beam spot size, beam position, incident direction, and energy of the beam can be obtained. The Bragg curve acquired from PBDOSE with statistical uncertainties of 1.5% was almost identical to those measured by a commercial water phantom. Besides that, the lateral profiles revealed a remarkable agreement with Gafchromic EBT3 film measurements within differences less than 0.1 mm. PBDOSE shows great prospects in the accurate and efficient measurement of 3D dose distribution for carbon-ion therapy, and the clinical application of this system will improve the efficiency of regular QA procedures to a great extent.