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We present a data‐acquisition and ‐analysis framework for quasi‐elastic gamma‐ray scattering (QEGS) experiments at BL35XU of SPring‐8, equipped with an 840 kpixel CITIUS X‐ray detector operating at 17.4 kHz. The detector produces data at 27 GB s−1 (216 Gbps), and typical experiments involve acquisition over beam‐time periods longer than 24 h, generating datasets of 2.3 PB per day. To handle this volume, we constructed a data‐handling pipeline consisting of the detector, data reduction at the beamline and analysis tools at the data center. The data reduction employs field‐programmable gate array (FPGA)‐accelerated per‐pixel processing to reduce data entropy, followed by Zstandard compression on CPUs, achieving an average compression ratio of over 8000. The compressed data are transferred to the SPring‐8 data center within two to three minutes of data acquisition. At the data center, analysis tools are provided via the Open OnDemand platform, enabling incremental integration and spectral analysis through a web‐based interface without the need for high‐performance‐computing command‐line interaction. This data‐handling pipeline has been applied in QEGS user experiments, where it enabled timely feedback on experimental data, with integrated results available within six minutes and spectral analysis within seven minutes of integration. A high‐throughput field‐programmable gate array (FPGA)‐accelerated data‐reduction and ‐analysis pipeline combined with high‐performance computing enables the continuous handling of a 216 Gbps data stream from quasi‐elastic gamma‐ray scattering experiments at SPring‐8.

Ptychographic coherent diffraction imaging (PCDI) is a synchrotron X-ray microscopy technique that provides high spatial resolution and a wide field of view. To improve the performance of PCDI, the performance of the synchrotron radiation source and imaging detector should be improved. In this study, ptychographic diffraction pattern measurements using the CITIUS high-speed X-ray image detector and the corresponding image reconstruction are reported. X-rays with an energy of 6.5 keV were focused by total reflection focusing mirrors, and a flux of ∼2.6 × 10 10  photons s −1 was obtained at the sample plane. Diffraction intensity data were collected at up to ∼250 Mcounts s −1 pixel −1 without saturation of the detector. Measurements of tantalum test charts and silica particles and the reconstruction of phase images were performed. A resolution of ∼10 nm and a phase sensitivity of ∼0.01 rad were obtained. The CITIUS detector can be applied to the PCDI observation of various samples using low-emittance synchrotron radiation sources and to the stability evaluation of light sources.

The Simons Observatory (SO) is an upcoming cosmic microwave background(CMB) experiment located on Cerro Toco, Chile, that will map the microwave sky in temperature and polarization in six frequency bands spanning 27 to 285 GHz. SO will consist of one 6-meter Large Aperture Telescope (LAT) fielding∼30,000 detectors and an array of three 0.42-meter Small Aperture Telescopes (SATs) fielding an additional 30,000 detectors. This synergy will allow for the extremely sensitive characterization of the CMB over an-gular scales ranging from an arcmin to tens of degrees, enabling a wide range of scientific output. Here we focus on the SATs targeting degree angular scales with successive dichroic instruments observing at Mid-Frequency (MF: 93/145 GHz), Ultra-High-Frequency (UHF:225/285 GHz), and Low-Frequency (LF: 27/39 GHz). The three SATs will be able to map∼10% of the sky to a noise level of∼2 μK-arcmin when combining 93 and 145 GHz. The multiple frequency bands will allow the CMB to be separated from galactic foregrounds (primarily synchrotron and dust), with the primary science goal of characterizing the primordial tensor-to-scalar ratio, r, at a target level ofσ(r)≈0.003.

This paper introduces a deep learning (DL)-based method for phase retrieval tailored to single-shot, multiple-frame coherent X-ray diffraction imaging (CXDI), designed specifically for visualizing local nanostructural dynamics within a larger sample. Current phase retrieval methods often struggle with achieving high spatiotemporal resolutions, handling dynamic imaging, and managing computational costs, which limits their applicability in observing nanostructural dynamics. This study addresses these gaps by developing a novel method that leverages a feedforward architecture with a physics-informed strategy utilizing measurement settings, enabling the reconstruction of dynamic “movies\" from time-evolving diffraction images of the illuminated area. The method incorporates key enhancements, such as temporal convolution blocks to capture spatiotemporal correlations and a unified TV regularization applied to the reconstructed object, resulting in improved noise reduction and spatial smoothness. An expanded evaluation framework, including multiple metrics and systematic sensitivity analysis, is employed to comprehensively assess the method’s performance and robustness. Proof-of-concept experiments, including numerical simulations and imaging experiments of a moving Ta test chart and colloidal gold particles (dispersed in aqueous polyvinyl alcohol solutions) with synchrotron hard X-rays, validate the high imaging performance of this method. Experimental results demonstrate that structures in the sample have been successfully reconstructed at short exposure times, significantly outperforming both traditional methods and current DL-based methods. The proposed method provides efficient and reliable reconstruction of dynamic images with low computational costs, making it suitable for exploring fast-evolving phenomena in synchrotron- or free-electron laser-based applications requiring high spatiotemporal resolutions.

Synchrotron-radiation-based quasi-elastic scattering using multiline Mössbauer radiation from a nuclear Bragg monochromator allows for dynamic studies on timescales ranging from sub-nanoseconds to several tens of nanoseconds, which have not been fully covered by X-ray-based techniques. However, the potential performance of this technique has not yet been fully explored. In this study, a new, high-efficiency energy analyser system composed of three Mössbauer absorbers was developed, enabling more efficient analysis of the quasi-elastic scattering. The absorption depth of the absorption-type, energy-domain, quasi-elastic scattering spectra increased two-fold with the introduction of the new analyser, indicating the high measurement efficiency of the new system. In addition, both experimental and simulation studies showed that the intermediate scattering function, which includes the dynamic information of the sample, can be accurately visualised via Fourier-transformation-based analysis of the experimental energy spectra. The new system and analytical methodology can be applied to various systems such as liquids, glasses, and soft-matter systems.

We have searched for proton decays via p→ e+ π0 and p→ μ+ π0 using data from a 91.7 kton-year exposure of Super-Kamiokande-I and a 49.2 kton-year exposure of Super-Kamiokande-II. Super-Kamiokande-II has comparable performances with Super-Kamiokande-I for the proton decays search even with a half density of photomultiplier tubes. No candidate events are observed with expected backgrounds induced by atmospheric neutrinos of 0.3 events for both decay modes. From these results, we set the most stringent lower limits on the partial lifetime at a 90% confidence level.

The Simons Array (SA) is a cosmic microwave background (CMB) polarization experiment comprised of three telescopes that will observe the CMB at 90, 150, 220, and 270 GHz with more than 22,000 Transition Edge Sensor (TES) bolometers. The cryogenic receivers inside each telescope are named POLARBEAR-2a, POLARBEAR-2b, and POLARBEAR-2c (PB-2a, PB-2b, and PB-2c, respectively). To allow for the large number of detectors, SA uses frequency-division multiplexing with multiplexing factor of 40. We describe the process developed to assemble the readout circuit repeatably for SA. After assembly, we characterize the readout circuit and TESs at cryogenic temperatures in a condition of negligible incident optical power. Impedances in the readout circuit bias our estimates of TES parameters, and we describe a method to account for this.

We report on the assessment of the imaging performance of CITIUS -- a high-speed X-ray detector developed for the large-scale synchrotron radiation facility SPring-8-II -- for heavy charged particles and neutrons. To characterize the detector response, an irradiation experiment was performed using alpha particles from an \\(^241\\)Am source at four back-bias voltages of 400V, 300 V, 200 V, and 170 V, thereby controlling the amount of charge diffusion. A Geant4 model of the experiment was constructed, and four model parameters were determined by template fitting to the measured signal cluster shape distributions. The best-fit values are: an intrinsic energy spread of 5% for the source, a gold fraction of 0.4 for the Au-Pd coating, a lateral charge diffusion spread of 26.5 \\(\\)m over a drift distance of 650 \\(\\)m at 400V back-bias, and a per-pixel readout noise of 10000 \\(e^-\\) in the medium-gain channel. Using the obtained sensor model, simulations were performed for 4 MeV alpha particles and cold neutrons to evaluate the expected spatial resolution. In both cases, simulated CITIUS, when operated in a gain-selecting mode between high and medium gains, yields a substantial improvement: at a pixel size of 70 \\(\\)m for example, the resolution improves from 9.1 \\(\\)m to 1.2 \\(\\)m for alpha particles, and from 26 \\(\\)m to 1.9 \\(\\)m for cold neutrons. These results suggest that two key features of CITIUS -- its gain-selecting architecture and the substantial charge sharing enabled by the long carrier drift distance -- extend its imaging capabilities beyond X-rays to heavy charged particles and neutrons.

Precipitable water vapour (PWV) strongly affects the quality of data obtained from millimetre- and submillimetre-wave astronomical observations, such as those for cosmic microwave background measurements. Some of these observatories have used radiometers to monitor PWV. In this study, PWV was measured from 2021 April to 2022 April using Global Navigation Satellite System (GNSS) instruments in the Atacama Desert, Chile, where several millimetre- and submillimetre-wave telescopes are located. We evaluated the accuracy of these measurements by comparing them to radiometer measurements. We calculated the PWV from GNSS data using CSRS-PPP (Canadian Spatial Reference System Precise Point Positioning), an online software package. When using GNSS data alone, the estimated PWV showed a systematic offset of +1.08 mm. When combining GNSS data with data from a barometer, which was co-located with the GNSS receiver, the estimated PWV showed a lower systematic offset of -0.05 mm. The GNSS PWV showed a statistical uncertainty of 0.52 mm with an averaging time of an hour. Compared to other PWV measurement methods, GNSS instruments are robust in bad weather conditions, have sufficient time resolution, and are less expensive. By demonstrating good accuracy and precision in low-PWV conditions, this paper shows that GNSS instruments are valuable tools for PWV measurements for observing site evaluation and data analysis for ground-based telescopes.