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We propose a novel method for producing very-neutron-rich hypernuclei and corresponding resonance states by employing charge-exchange reactions via pp( 12 C, 12 N K + )n Λ with single-charge-exchange and ppp( 9 Be, 9 C K + )nn Λ with double-charge-exchange, both of which produce Λ K + in a target nucleus. The feasibility of producing very-neutron-rich hypernuclei using the proposed method was analysed by applying an ultra-relativistic quantum molecular dynamics model to a 6 Li + 12 C reaction at 2 A GeV. The yields of very-neutron-rich hypernuclei, signal-to-background ratios, and background contributions were investigated. The proposed method is a powerful tool for studying very-neutron-rich hypernuclei and resonance states with a hyperon for experiments employing the Super-FRS facility at FAIR and HFRS facility at HIAF. [ABSTRACT FROM AUTHOR]

Neutron imaging is a nondestructive inspection technique that has a wide range of applications. One of the important aspects of neutron imaging is achieving a micrometer-scale spatial resolution. The development of a high-resolution neutron detector is a challenging task. As one potential solution to this task, we investigate whether neutron detectors based on fine-grained nuclear emulsions are suitable for high-resolution neutron imaging applications. High track density is necessary to improve the quality of neutron imaging. However, the available track analysis methods are difficult to apply under high track density conditions. Simulated images are used to determine the required track density for neutron imaging. A track density of the order of 10 4 tracks per 100 × 100 μ m 2 is sufficient to utilize neutron detectors for imaging applications. Contrast resolution was also investigated for image datasets with various track densities and neutron transmission rates. Moreover, experiments were performed for the neutron imaging of gadolinium-based gratings with known geometries. The grating structures were successfully resolved. The calculated 1 σ 10%–90% edge response using the grayscale optical images of the grating slit with a periodic structure of 9 μ m was 0.945 ± 0.004 μ m. [ABSTRACT FROM AUTHOR]

Neutron imaging is a nondestructive and noninvasive inspection technique with a wide range of potential applications. However, the fundamentals of this technique still need to be improved, one of which involves achieving micrometer scale or even better resolution, which is a challenging task. Recently, a high-resolution neutron imaging device based on fine-grained nuclear emulsions was developed. Although these detectors demonstrate exceptionally high resolutions, they have several limitations. Furthermore, these detectors require an additional chemical development process and are thus not reusable. To overcome these limitations, we investigated whether neutron imaging devices based on fluorescent nuclear track detectors were suitable for high-resolution neutron imaging. Fluorescent nuclear track detectors are reusable solid-state detectors that do not require additional chemical processing. A novel technique combining neutron imaging based on fluorescent nuclear track detectors with a neutron converter layer formed using B C was developed with unprecedented resolution. The neutron imaging of a gadolinium-based grating with a periodic structure of 9 m was performed using the proposed fluorescent nuclear track detector-based neutron imaging device, and the grating structure was successfully resolved. The measured resolution was 0.887 ± 0.009 m, which is the 1 10–90% edge response obtained using optical images of the fluorescent nuclear track detectors. [ABSTRACT FROM AUTHOR]

A novel method was developed to detect double- Λ hypernuclear events in nuclear emulsions using machine learning techniques. The object detection model, the Mask R-CNN, was trained using images generated by Monte Carlo simulations, image processing, and image-style transformation based on generative adversarial networks. Despite being exclusively trained on He Λ Λ 6 events, the model achieved a detection efficiency of 93.8% for He Λ Λ 6 and 82.0% for H Λ Λ 5 events in the produced images. In addition, the model demonstrated its ability to detect the He Λ Λ 6 event named the Nagara event, which is the only uniquely identified double- Λ hypernuclear event reported to date. It also exhibited a proper segmentation of the event topology. Furthermore, after analyzing 0.2% of the entire emulsion data from the J-PARC E07 experiment utilizing the developed approach, six new candidates for double- Λ hypernuclear events were detected, suggesting that more than 2000 double-strangeness hypernuclear events were recorded in the entire dataset. This method is sufficiently effective for mining more latent double- Λ hypernuclear events recorded in nuclear emulsion sheets, significantly reducing the time required for manual visual inspection by a factor of five hundred. [ABSTRACT FROM AUTHOR]

Fluorescent nuclear track detectors (FNTDs) based on Al 2 O 3 :C,Mg crystals are luminescent detectors that can be used for dosimetry and detection of charged particles and neutrons. These detectors can be utilized for imaging applications where a reasonably high track density, approximately of the order of 1 × 1 0 4 tracks in an area of 100 × 100 μ m 2 , is required. To investigate the reusability of FNTDs for imaging applications, we present an approach to perform optical bleaching under the required track density conditions. The reusability was assessed through seven irradiation-bleaching cycles. For the irradiation, the studied FNTD was exposed to alpha-particles from an 241Am radioactive source. The optical bleaching was performed by means of ultraviolet laser light with a wavelength of 355 nm. Three dedicated regions on a single FNTD with different accumulated track densities and bleaching conditions were investigated. After every irradiation-bleaching cycle, signal-to-noise ratio was calculated to evaluate FNTD performance. It is concluded that FNTDs can be reused at least seven times for applications where accumulation of a high track density is required. • FNTDs can be used for the micrometer scale neutron imaging applications under high accumulated track density condition. • The optical bleaching of the FNTDs was investigated using a UV laser light of 355 nm. • The re-usability of the FNTDs was investigated through seven repeated iterations of the irradiation of alpha particles. • FNTDs can be re-used at least seven times for the applications where accumulation of high track density is required. [ABSTRACT FROM AUTHOR]