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The displacement damage dose (DDD) is a common index used to predict the life of semiconductor devices employed in space-based environments where they will be exposed to radiation. The DDD is commonly estimated from the non-ionizing energy loss based on the Norgett-Robinson-Torrens (NRT) model, although a new definition for a so-called effective DDD considers the molecular dynamic (MD) simulation with the amorphization in semiconductors. The present work developed a new model for calculating the conventional and effective DDD values for silicon carbide (SiC), indium arsenide (InAs), gallium arsenide (GaAs) and gallium nitride (GaN) semiconductors. This model was obtained by extending the displacement per atom tally implemented in the particle and heavy ion transport code system (PHITS). This new approach suggests that the effective DDD is higher than the conventional DDD for arsenic-based compounds due to the amorphization resulting from direct impacts, while this relationship is reversed for SiC because of recombination defects. In the case of SiC and GaN exposed to protons, the effective DDD/conventional DDD ratio decreases with proton energy. In contrast, for InAs and GaAs, this ratio increases to greater than 1 at proton energies up to 100 MeV and plateaus because the defect production efficiency, which is the ratio of the number of stable displacements at the end of collision cascade simulated by MD simulations to the number of defects calculated by NRT model, does not increase at damage energy values above 20 keV. The practical application of this model was demonstrated by calculating the effective DDD values for semiconductors sandwiched between a thin glass cover and an aluminum plate in a low-Earth orbit. The results indicated that the effective DDD could be dramatically reduced by increasing the glass cover thickness to 200 μm, thus confirming the importance of shielding semiconductor devices used in space. This improved PHITS technique is expected to assist in the design of semiconductors by allowing the effective DDD values for various semiconductors having complex geometries to be predicted in cosmic ray environments.

Optimal ligament balance is crucial for successful total knee arthroplasty (TKA), which is a standard procedure for managing end-stage knee osteoarthritis. However, the reported values of ligament balance vary due to different methodologies and population differences, which requires further studies. This study aimed to investigate the varus-valgus ligament balance in healthy knees of Japanese individuals and its relationship with lower limb alignment. The studyanalyzed64 knees from 33 healthy young adults using stress radiographs to measure varus-valgus laxity. The mechanical hip-knee-ankle angle, medial proximal tibial angle, and lateral distal femoral angles were determined using digital long-leg radiographs. Varus and valgus laxities were compared, and the relationship between ligament balance and alignment parameters was analyzed. Mean varus laxity (3.6°± 1.3°) was significantly greater than mean valgus laxity(2.9°± 1.0°) ( p <0.0001). No significant association was observed between ligament balance and alignment parameters. Healthy knees of Japanese individuals exhibited slightly greater varus laxity (0.7°) than valgus laxity, with no correlation observed between ligament balance and lower limb alignment. The finding underscores the importance of recognizing alignment diversity while noting that alignment does not influence ligament balance; this is particularly relevant in modern TKA techniques focusing on patient-specific joint and ligament reconstructions. The study’s findings could help formulate strategies benefiting knee osteoarthritis management.

To provide the athermal recombination corrected dpa (arc-dpa) cross sections for proton, deuteron and heavy ion irradiations in the energy range from 1 MeV/u to 3 GeV/u., the defect production efficiencies for aluminium, copper and tungsten were implemented in the radiation damage model in PHITS. In general, the dpa cross section is large with increasing the number of protons of incident particle. For high-energy (around 1 GeV/u) proton and deuteron irradiation, the dpa cross section is close to that under 12 C irradiation due to secondaries produced by the nuclear reaction. The ratio of arc-dpa cross section to the conventional Norgett-Robinson-Torrens dpa (NRT-dpa) cross section is around 0.2 with incident energies over 100 MeV for proton and deuteron irradiations. For the case of 12 C and 48 Ca, this ratio is ranged from 0.3 to 0.4 for incident beam energies below 3 GeV/u.

This paper presents the latest updates on PHITS, a versatile radiation transport code, focusing specifically on track-structure models. Track structure calculations are methods used to simulate the movement of charged particles while explicitly considering each atomic reaction. Initially developed for radiation biology, these calculation methods aimed to analyze the radiation-induced damage to DNA and chromosomes. Several track-structure calculation models, including PHITS-ETS, PHITS-ETS for Si, PHITS-KURBUC, ETSART, and ITSART, have been developed and implemented for PHITS. These models allow users to study the behavior of various particles at the nano-scale across a wide range of materials. Furthermore, potential applications of track-structure calculations have also been proposed so far. This collection of track-structure calculation models, which encompasses diverse conditions, opens up new avenues for research in the field of radiation effects.

In high-intensity proton accelerator facilities, it is crucial to evaluate the damage of beam-interception materials and accelerator components, such as a superconducting magnet coil and cavity. The displacement per atom (dpa) is used as a damage index derived by integrating the particle flux and the displacement cross section. Although the dpa is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. To obtain the data for superconducting materials for high-intensity accelerators and magnets, we measured the displacement cross section of Nb for proton irradiation with a kinetic energy range between 0.4 and 3 GeV at J-PARC. The present experimental results were compared with the calculation of PHITS code and Karlsruhe Institute of Technology (KIT) evaluation using both NorgerttRobinson-Torrens (NRT) and the athermal recombination corrected dpa (arc-dpa) models. The experiment showed that the widely utilized NRT model overestimates the cross section by 50%. It is also found that the arc-dpa model shows remarkably good agreement with the present data.

Purpose: In osteoarthritis of the hip, the pain may be strong even if the deformity is mild, but the pain may be mild even if the deformity is severe. If the factors related to the pain can be identified on imaging, reducing such factors can alleviate the pain, and effective measures can be taken for cases where surgery cannot be performed. In addition, imaging findings related to the pain are also important information for determining the procedures and the timing of surgery. Thus, the purpose of this study was to identify the differences in features of osteoarthritis seen on imaging between painless and painful osteoarthritis of the hip. Methods: The subjects were the patients with hip osteoarthritis who visited our department in 2015 and who underwent x-ray, computed tomography (CT), and magnetic resonance imaging (MRI), a total of 29 patients (54 hip joints; mean age 63 years; 8 males and 21 females). The degree of osteoarthritis was determined using the Tönnis grade from the x-ray image. The cartilage morphology, intensity changes of bone marrow on MRI (subchondral bone marrow lesions [BMLs]), osteophytes, joint effusions, and paralabral cysts were scored based on the Hip Osteoarthritis MRI Scoring System (HOAMS). The cross-sectional area of the psoas major muscle at the level of the iliac crest was measured on CT, and the psoas index (PI; the cross-sectional area ratio of the psoas major muscle to the lumbar 4/5 intervertebral disc) was calculated to correct for the difference in physique. Then, the relationships between these and visual analog scale (VAS) scores of pains were evaluated. Results: The average VAS was 55.4 ± 39 mm. The PI and all items of HOAMS correlated with the VAS. The average VAS of Tönnis grade 3 osteoarthritis was 75.8 ± 26 mm. When investigating only Tönnis grade 3 osteoarthritis, the differences between cases with less than average pain and those with above average pain were the BML score in the central-inferior femoral head (P = .0213), the osteophyte score of the inferomedial femoral head (P = .0325), and the PI (P = .0292). Conclusion: Investigation of the differences between painless and painful osteoarthritis of the hip showed that the cases with more pain have BMLs of the femoral head on MRI that extend not only to the loading area, but also to the central-inferior area. Even with the same x-ray findings, the pain was stronger in patients with severe psoas atrophy. Thus, the instability due to muscle atrophy may also play a role in the pain of hip osteoarthritis.

The Working Party on International Nuclear Data Evaluation Co-operation Subgroup 47 (WPECSG47) entitled \"Use of Shielding Integral Benchmark Archive and Database for Nuclear Data Validation\" was organised from 2019 and 2022 with the objectives to promote more systematic and wider use of shielding benchmark experiments in nuclear data (ND) and transport code validation and development, to provide feedback on the Shielding Integral Benchmark Archive and Database (SINBAD), and to promote its further development in coordination with the Expert Group on Physics of Reactor Systems (EGPRS). Altogether 9 meetings, the large majority (8) held remotely, were organised during the past 3 years to discuss the experience on the use of SINBAD, evaluation of new benchmarks and improvements to be contributed to the database which was severely neglected and lacking maintenance over the past ⇠ 10+ years. Several proposals for new or updated benchmark evaluation were presented and discussed, such as FNG copper, LLNL pulsed spheres, CIAE iron sphere, KFK 1977 gamma measurements, Rez Fe sphere, ASPIS, ORNL Oxygen broomstick, TIARA and others. Complementing the database with new features was also discussed, for example providing the nuclear data sensitivity profiles more systematically would facilitate and better guide the use of data. Information on the geometry, (radiation source) and materials available in CAD format is expected to allow an easier and less error prone reference for computational model preparation and a potential input to CAD based workflows. Inputs for various transport codes and other benchmark data from participants have been shared via the NEA GitLab which could hopefully in the future evolve and form a bases for critically checked and validated benchmark data. Future development of SINBAD will be monitored by EGPRS and the newly created SINBAD Task Force.

Double-differential neutron production cross sections (DDXs) for 200-MeV deuteron induced reactions on Li, Be, C, Al, Cu, Nb, In, Ta, and Au were measured at forward emission angles ranging from 0° to 25° by means of a time of flight (TOF) method with EJ301 liquid organic scintillators. The measured DDXs were compared with JENDL-5 and TENDL-2021 nuclear data, and theoretical model calculations using DEURACS and PHITS codes. It was found that the JENDL-5 and DEURACS calculation are in better agreement with the measured DDXs than the PHITS calculation, while TENDL-2021 fails to reproduce both the spectral shape and magnitude of the measured DDXs for all the targets.

This study aimed to define basicervical and transcervical shear fractures using area classification and to determine the optimal osteosynthesis implants for them. The clinical outcomes of 1042 proximal femur fractures were investigated. A model of the proximal femur of a healthy adult was created from computed tomography images, and basicervical and transcervical shear fractures were established in the model. Osteosynthesis models were created using a short femoral nail with a single lag screw or two lag screws and a long femoral nail with a single lag screw or two lag screws. The minimum principal strains of the fracture surfaces were compared when the maximum loads during walking were applied to these models using finite element analysis software. Basicervical fractures accounted for 0.96% of all proximal femur fractures, 67% of which were treated with osteosynthesis; the failure rate was 0%. Transcervical shear fractures accounted for 9.6% of all proximal femur fractures, 24% of which were treated with osteosynthesis; the failure rate was 13%. Finite element analysis showed that transcervical shear fracture has high instability. To perform osteosynthesis, multiple screw insertions into the femoral head and careful postoperative management are required; joint replacement should be considered to achieve early mobility.

For the research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research using the Kyoto University Critical Assembly combined with the fixed-field alternating gradient (FFAG) accelerator, we are conducting a series of experiments on double-differential neutron yields using the FFAG accelerator at Kyoto University. This paper presents an overview of the experiments together with preliminary results.