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Muons are part of natural cosmic radiation but can also be generated at spallation sources for material science and particle physics applications. Recently, pulsed muons have been used to characterize the density of free charge carriers in semiconductors and their recombination lifetime. Muon beam irradiation can also result in the formation of dilute levels of crystal defects in silicon. These crystal defects are only detected in high carrier lifetime silicon samples that are highly sensitive to defects due to their long recombination lifetimes. This work investigates the characteristics of these defects in terms of their formation, recombination activity, and deactivation. Charge carrier lifetime assessments and photoluminescence imaging have great sensitivity to measure the generated defects in high-quality silicon samples exposed to ∼4 MeV (anti)muons and their recombination activity despite the extremely low concentration. The defects reduce the effective charge carrier lifetime of both p- and n-type silicon and appear to be more detrimental to n-type silicon. Defects are created by transmission of muons through the wafer, and there are indications that slowed or implanted muons may create additional defects. In a post-exposure isochronal annealing study, we observe that annealing at temperatures of up to 450 °C does not by itself fully deactivate the defects. A recovery of charge carrier lifetime was observed when the annealing was combined with Al2O3 surface passivation, probably due to passivation of bulk defects from hydrogen from the dielectric film. [ABSTRACT FROM AUTHOR]

Muon radiography, which relies on measuring the absorption and attenuation of muons as they pass through matters, offers a new imaging technique capable of revealing the internal structure of large objects. Recent technological advancement allows for the application or testing of muon radiography in various fields, including mining, civil engineering, security check, etc. This study investigates the factors that influence muon radiography, which is used in density inversion, through simulations and experiments. The materials considered for density inversion include water, standard rock, and iron. Our simulation studies show that the number of events detected and selected has an impact on the reconstruction results, and several factors, such as multiple Coulomb scattering processes, recording time, and spatial resolution, which influence the number of muons, must be taken into account when measuring the rock density. We design and conduct a laboratory scale experiment based on the simulation results. We filter the 220 h of recording signals through time coincidence and straight-line fitting to obtain the selected events. Our results reveal that the statistical error of muons survival ratio in recording time significantly impacts the inversion result and decreases the error can improve accuracy greatly. In the experiment, the deviation between the inversion mean value and the expected value can be reduced to 2.4%–2.9% for iron, 7% for water, and 1.5% for standard rock. This density inversion approach provides insight into future density detection of underground structures. [ABSTRACT FROM AUTHOR]

The Apollo 16 regolith breccia sample suite provides a record of lunar regolith formation from the basin‐forming epoch (~3.9 Ga) through to a time of declining impactor flux (~2 Ga). These rocks have been characterized into three groups: the “ancient,” “young,” and “soil‐like” regolith breccias on the basis of their petrographic characteristics, and, in the case of the “ancient” and “young” regolith breccias, noble gas inventory. This study investigates the as‐yet unexamined noble gas records of the “soil‐like” regolith breccias to understand more recent regolith evolution processes that occurred at the Apollo 16 landing site. The range of gas concentrations measured for each noble gas in these samples is comparable to those previously reported for the local Apollo 16 soils. The “soil‐like” regolith breccias were found to be more gas rich than the gas poor “young” and “ancient” regolith breccias, consistent with them having formed from comparatively mature soil(s). Our results further confirm the scientific value of lunar regolith breccias and bulk regolith samples as probes of the impact history and the space environment of the lunar surface across a wide range of time. [ABSTRACT FROM AUTHOR]

A strong Forbush decrease, i.e., suppression of the flux of galactic cosmic rays recorded on Earth, was observed by the global network of ground-based neutron monitors (NMs) on 24 – 25 March 2024. The decrease was very unusual as characterised by so rapid recovery that a false Ground-level enhancement (GLE) alarm was produced by the corresponding warning systems. Here we present the first comprehensive collection and analysis of the available data for this event. The event was highly anisotropic as exhibited in a 3-h spread of the deep-phase timing for different NMs. The anisotropy was focused nearly at the anti-sunward direction with a narrow cone of 20 – 30 °. The heliospheric situation leading to this unusual Forbush decrease was quite complex. An analysis of first look records was performed, considering the stations acceptance, taking into account the complex geomagnetic conditions. A leader fraction analysis indicates that the recovery phase of the event was rigidity-independent and had essentially the same spectral shape as the pre-event period. A summary of the solar-terrestrial phenomena is provided to assist in future work on modelling this complex event. [ABSTRACT FROM AUTHOR]

Interplanetary travel poses serious risks because of Galactic cosmic radiations (GCRs). A recent study by Sanghee et al. revealed long‐term cognitive impairments in female mice exposed to a 33‐beam GCR simulator, highlighting persistent risks for astronauts. The study's use of touchscreen tasks, similar to human cognitive tests, enhances its relevance for space missions. Additionally, the antioxidant/anti‐inflammatory compound CDDO‐EA showed potential in mitigating these cognitive deficits. While offering critical insights into GCR effects, the study emphasizes the need for further research into protective strategies, including dietary interventions, to ensure astronaut safety on extended missions beyond Earth's protective shield. [ABSTRACT FROM AUTHOR]

While cosmic rays (E ≳ 1 GeV) are well coupled to a galaxy's interstellar medium (ISM) at scales of L > 100 pc, adjusting stratification and driving outflows, their impact on small scales is less clear. Based on calculations of the cosmic-ray diffusion coefficient from observations of the grammage in the Milky Way, cosmic rays have little time to dynamically impact the ISM on those small scales. Using numerical simulations, we explore how more complex cosmic-ray transport could allow cosmic rays to couple to the ISM on small scales. We create a two-zone model of cosmic-ray transport, with the cosmic-ray diffusion coefficient set at the estimated Milky Way value in cold gas but smaller in warm gas. We compare this model to simulations with a constant diffusion coefficient. Quicker diffusion through cold gas allows more cold gas to form compared to a simulation with a constant, small diffusion coefficient. However, slower diffusion in warm gas allows cosmic rays to take energy from the turbulent cascade anisotropically. This cosmic-ray energization comes at the expense of turbulent energy which would otherwise be lost during radiative cooling. Finally, we show our two-zone model is capable of matching observational estimates of the grammage for some transport paths through the simulation. [ABSTRACT FROM AUTHOR]

The IceCube Collaboration has reported possible detections of high-energy neutrinos from nearby Seyfert galaxies. While central hot coronae are proposed as the primary neutrino production site, the exact coronal cosmic ray energy budget has been loosely constrained. In this study, we propose a new stringent upper bound on the coronal cosmic ray energy budget of Seyfert galaxies, considering both accretion dynamics and observed properties of radio-quiet Seyfert galaxies. Notably, even under the calorimetric condition where cosmic rays lose all their energy, our limit indicates that the coronal neutrino flux of NGC 1068 is about an order of magnitude fainter than the observed levels. This discrepancy suggests the need for further theoretical and observational investigations on the IceCube signals from Seyfert galaxies. [ABSTRACT FROM AUTHOR]

Human exploration of the solar system will expose crew members to galactic cosmic radiation (GCR), with a potential for adverse health effects. GCR particles (protons and ions) move at nearly the speed of light and easily penetrate space station walls, as well as the human body. Previously, we have shown reactivation of latent herpesviruses, including herpes simplex virus, Varicella zoster virus, Epstein–Barr virus, and cytomegalovirus (CMV), during stays at the International Space Station. Given the prevalence of latent CMV and the known propensity of space radiation to cause alterations in many cellular processes, we undertook this study to understand the role of GCR in reactivating latent CMV. Latently infected Kasumi cells with CMV were irradiated with 137Cs gamma rays, 150 MeV protons, 600 MeV/n carbon ions, 600 MeV/n iron ions, proton ions, and simulated GCR. The CMV copy number increased significantly in the cells exposed to radiation as compared with the non-irradiated controls. Viral genome sequencing did not reveal significant nucleotide differences among the compared groups. However, transcriptome analysis showed the upregulation of transcription of the UL49 ORF, implicating it in the switch from latent to lytic replication. These findings support our hypothesis that GCR may be a strong contributor to the reactivation of CMV infection seen in ISS crew members. [ABSTRACT FROM AUTHOR]

In 1889 the German poet and novelist Theodor Fontane wrote the popular literary ballad "Herr von Ribbeck auf Ribbeck im Havelland." The Squire von Ribbeck is described as a gentle and generous person, who often gives away pears from his pear trees to children passing by and continued donating pears after his death. Now, 135 years later the rock called Ribbeck is giving us insight into processes that happened 4.5 billion years ago. The meteorite Ribbeck (official find location: 52°37′15″N, 12°45′40″E) fell January 21, 2024, and has been classified as a brecciated aubrite. This meteoroid actually entered the Earth's atmosphere at 00:32:38 UTC over Brandenburg, west of Berlin, and the corresponding fireball was recorded by professional all sky and video cameras. More than 200 pieces (two proved by radionuclide analysis to belong to this fresh fall) were recovered totaling about 1.8 kg. Long‐lived radionuclide and noble gas data are consistent with long cosmic ray exposure (55–62 Ma) and a preatmospheric radius of Ribbeck between 20 and 30 cm. The heavily brecciated aubrite consists of major (76 ± 3 vol%) coarse‐grained FeO‐free enstatite (En99.1Fs<0.04Wo0.9), with a significant abundance (15.0 ± 2.5 vol%) of albitic plagioclase (Ab95.3 An2.0Or2.7), minor forsterite (5.5 ± 1.5 vol%; Fo99.9) and 3.5 ± 1.0 vol% of opaque phases (mainly sulfides and metals) with traces of nearly FeO‐free diopside (En53.2Wo46.8) and K‐feldspar (Ab4.6Or95.4). The rock has a shock degree of S3 (U‐S3), and terrestrial weathering has affected metals and sulfides, resulting in the brownish appearance of rock pieces and the partial destruction of certain sulfides already within days after the fall. The bulk chemical data confirm the feldspar‐bearing aubritic composition. Ribbeck is closely related to the aubrite Bishopville. Ribbeck does not contain solar wind implanted gases and is a fragmental breccia. Concerning the Ti‐ and O‐isotope compositions, the data are similar to those of other aubrites. They are also similar to E chondrites and fall close to the data point for the bulk silicate Earth (BSE). Before the Ribbeck meteoroid entered Earth's atmosphere, it was observed in space as asteroid 2024 BX1. The aphelion distance of 2024 BX1's orbit lies in the innermost region of the asteroid belt, which is populated by the Hungaria family of minor planets characterized by their E/X‐type taxonomy and considered as the likely source of aubrites. The spectral comparison of an average large‐scale emission spectrum of Mercury converted into reflectance and of the Ribbeck meteorite spectrum does not show any meaningful similarities. [ABSTRACT FROM AUTHOR]

Precise measurements of Cr isotopic composition of terrestrial impactites have successfully provided evidence for the presence of extraterrestrial material and have, in some cases, allowed the identification of the type of impactor responsible for the formation of the impact structure. The high Cr abundance in most meteorite groups aids in detecting extraterrestrial contamination while their distinct isotopic compositions can help with the identification of the nature of the projectile. However, this common approach of detection and identification of extraterrestrial contamination using mass‐independent 53Cr and 54Cr variations fails when the impactor type is an iron meteorite because of their low Cr abundances (which are in a similar range to terrestrial rocks). The present study demonstrates the viability of a spallogenic Cr contribution in iron meteorites (resulting from their long cosmic ray exposure times), which compensates for their low Cr abundances and facilitates the identification of iron‐meteoritic contamination in terrestrial impactites. Thus, it broadens the scope of impactors (and impactites) that can be investigated using mass‐independent Cr isotopes from solely chondrites and primitive achondrites to include iron meteorites. The Wabar impact craters are an optimal candidate for this study, characterized by low weathering, diverse impactites, partial meteorite survival, substantial impactor material contamination, and a felsic target lithology with low background Cr concentration. The Cr isotopic composition of the Wabar background sand, which represents the target lithology, is indistinguishable from the terrestrial Cr isotopic composition range, whereas the Wabar iron meteorites show coupled spallogenic excesses in ε53Cr and ε54Cr. The Cr isotopic compositions of Wabar impactites show resolved deviations from the terrestrial Cr isotopic composition, thereby indicating the presence of Wabar meteoritic contamination. Moreover, the study demonstrates that even an impactor with a non‐carbonaceous chondritic origin, such as a IIIAB iron meteorite, can have a carbonaceous chondrite‐like signature in ε54Cr anomalies due to spallogenic Cr contamination. The study advocates for a comprehensive investigation combining platinum group elements and Cr (and/or Ni, Ru) isotopes to accurately characterize impactor types. [ABSTRACT FROM AUTHOR]

The goal of this work is to characterize the secondary neutron spectra produced by 1 GeV/u56Fe beam colliding with a thick cylindric aluminum target and to perform a quantitative comparison with simulated results obtained with Monte Carlo codes. The measurements were performed using extended-range Bonner sphere spectrometers at two positions (15° and 40°) with respect to the beam direction. The secondary radiation field was simulated using four Monte Carlo codes (FLUKA, MCNP6, Geant4 and PHITS) and several physical models of nuclei transport and interaction. Neutron and proton energy distributions were simulated for the experimental measurement positions. The simulated neutron spectra, together with data measured with Bonner sphere spectrometers, after carrying out the correction of the contributions induced by the secondary protons, were used as input for the MAXED spectrum unfolding code to obtain the measured neutron spectra. Unfolded neutron spectra were compared with simulated ones to carry out a quantitative analysis of the performance of the chosen Monte Carlo codes and their corresponding physical models. This comparison showed that, because of experimental uncertainties and physical models, there are no unique solutions for each measurement location, but a range of solutions where the true experimental neutron spectra probably lie. The results showed deviations between 4.23% and 8.42% for some simulated spectra. Regarding the total integral values of neutron fluence and ambient equivalent dose, the unfolded neutron spectra showed deviations lower than 2%. [ABSTRACT FROM AUTHOR]

Over the Nullarbor Plain in South Australia, the Desert Fireball Network detected a fireball on the night of June 1, 2019 (7:30 pm local time), and 6 weeks later recovered a single meteorite (42 g) named Arpu Kuilpu. This meteorite was then distributed to a consortium of collaborating institutions to be measured and analyzed by a number of methodologies including SEM‐EDS, EPMA, ICP‐MS, gamma‐ray spectrometry, ideal gas pycnometry, magnetic susceptibility measurement, μCT, optical microscopy, and accelerator and noble gas mass spectrometry techniques. These analyses revealed that Arpu Kuilpu is an unbrecciated H5 ordinary chondrite, with minimal weathering (W0‐1) and minimal shock (S2). The olivine and pyroxene mineral compositions (in mole%) are Fa: 19.2 ± 0.2 and Fs: 16.8 ± 0.2, further supporting the H5 type and class. The measured oxygen isotopes are also consistent with an H chondrite (δ17O‰ = 2.904 ± 0.177; δ18O‰ = 4.163 ± 0.336; Δ17O‰ = 0.740 ± 0.002). Ideal gas pycnometry measured bulk and grain densities of 3.66 ± 0.02 and 3.77 ± 0.02 g cm−3, respectively, yielding a porosity of 3.0% ± 0.7. The magnetic susceptibility of this meteorite is log χ = 5.16 ± 0.08. The most recent impact‐related heating event experienced by Arpu Kuilpu was measured by 40Ar/39Ar chronology to be 4467 ± 16 Ma, while the cosmic ray exposure age is estimated to be between 6 and 8 Ma. The noble gas isotopes, radionuclides, and fireball observations all indicate that Arpu Kuilpu's meteoroid was quite small (maximum radius of 10 cm, though more likely between 1 and 5 cm). Although this meteorite is a rather ordinary ordinary chondrite, its prior orbit resembled that of a Jupiter Family Comet (JFC) further lending support to the assertion that many cm‐ to m‐sized objects on JFC orbits are asteroidal rather than cometary in origin. [ABSTRACT FROM AUTHOR]

The γ -ray emission from the W51 complex is widely acknowledged to be attributed to the interaction between the cosmic rays (CRs) accelerated by the shock of supernova remnant (SNR) W51C and the dense molecular clouds in the adjacent star-forming region, W51B. However, the maximum acceleration capability of W51C for CRs remains elusive. Based on observations conducted with the Large High Altitude Air Shower Observatory (LHAASO), we report a significant detection of γ rays emanating from the W51 complex, with energies from 2 to 200 TeV. The LHAASO measurements, for the first time, extend the γ -ray emission from the W51 complex beyond 100 TeV and reveal a significant spectrum bending at tens of TeV. By combining the " π 0 -decay bump" featured data from Fermi-LAT, the broadband γ -ray spectrum of the W51 region can be well-characterized by a simple pp-collision model. The observed spectral bending feature suggests an exponential cutoff at ∼ 400 TeV or a power-law break at ∼ 200 TeV in the CR proton spectrum, most likely providing the first evidence of SNRs serving as CR accelerators approaching the PeV regime. Additionally, two young star clusters within W51B could also be theoretically viable to produce the most energetic γ rays observed by LHAASO. Our findings strongly support the presence of extreme CR accelerators within the W51 complex and provide new insights into the origin of Galactic CRs. [ABSTRACT FROM AUTHOR]

The utilization of device for the space explorations, the active material of the device must show resilience toward cosmos radiation. In this work, the radiation hardness of ZnGa2O4‐based deep ultra‐violet (DUV) photodetectors (PDs) is examined using γ‐ray irradiation. Responsivity of the photodetector at zero bias is found to improve from 0.98 to 1.94 mA W−1, the dark current increased from 0.11 to 5.6 pA, while photo‐to‐dark current ratio (PDCR) increased the from 3.2 × 103 to 3.1 × 104 and the photocurrent decay time improved from 220 to 190 ms. The high‐resolution X‐ray photoelectron spectra (HR‐XPS) of O 1s core level peak is deconvoluted into two main peaks namely, O(I) and O(II), where the lattice oxygen of ZnGa2O4 is identified by the O(I) peak, while its surface oxygen defect is represented by O(II). A clear increment is observed in the percentage of oxygen defect peak, O(II), from 6.82 to 53.19% after 200 kGy. Also, the device remains undeteriorated after 200 kGy irradiation, indicating it to be a radiation‐hard device. These characteristics allow ZnGa2O4 DUV PDs to function effectively in cosmic radiation environments with the capability to operate on zero‐bias, regardless of the γ‐radiation. [ABSTRACT FROM AUTHOR]

Galactic cosmic radiation (GCR) is an unavoidable risk to astronauts that may affect mission success. Male rodents exposed to 33‐beam‐GCR (33‐GCR) show short‐term cognitive deficits but reports on female rodents and long‐term assessment are lacking. We asked: What are the longitudinal behavioral effects of 33‐GCR on female mice? Also, can an antioxidant/anti‐inflammatory compound (CDDO‐EA) mitigate the impact of 33‐GCR? Mature (6‐month‐old) C57BL/6J female mice received CDDO‐EA (400 μg/g of food) or a control diet (vehicle, Veh) for 5 days and Sham‐irradiation (IRR) or whole‐body 33‐GCR (0.75Gy) on the 4th day. Three‐months post‐IRR, mice underwent two touchscreen‐platform tests: (1) location discrimination reversal (tests behavior pattern separation and cognitive flexibility, abilities reliant on the dentate gyrus) and (2) stimulus–response learning/extinction. Mice then underwent arena‐based behavior tests (e.g. open field, 3‐chamber social interaction). At the experiment's end (14.25‐month post‐IRR), an index relevant to neurogenesis was quantified (doublecortin‐immunoreactive [DCX+] dentate gyrus immature neurons). Female mice exposed to Veh/Sham vs. Veh/33‐GCR had similar pattern separation (% correct to 1st reversal). There were two effects of diet: CDDO‐EA/Sham and CDDO‐EA/33‐GCR mice had better pattern separation vs. their respective control groups (Veh/Sham, Veh/33‐GCR), and CDDO‐EA/33‐GCR mice had better cognitive flexibility (reversal number) vs. Veh/33‐GCR mice. One radiation effect/CDDO‐EA countereffect also emerged: Veh/33‐GCR mice had slower stimulus–response learning (days to completion) vs. all other groups, including CDDO‐EA/33‐GCR mice. In general, all mice showed normal anxiety‐like behavior, exploration, and habituation to novel environments. There was also a change relevant to neurogenesis: Veh/33‐GCR mice had fewer DCX+ dentate gyrus immature neurons vs. Veh/Sham mice. Our study implies space radiation is a risk to a female crew's longitudinal mission‐relevant cognitive processes and CDDO‐EA is a potential dietary countermeasure for space‐radiation CNS risks. [ABSTRACT FROM AUTHOR]

Depleted shergottites record unique information about the primary composition and differentiation of the mantle of Mars. Their petrology, geochemistry, and cosmic ray exposure and crystallization ages suggest that most of them were excavated by a single young impact in the Amazonian‐aged lava flows of the Tharsis and Elysium volcanic provinces. However, the difficulties of deriving consistent model ages for individual craters and inadequate evaluation of 3‐7 km craters capable of ejecting martian meteorites have not been settled. Here we perform detailed geological investigations and crater statistics in patches of impact melt deposits for potential source craters of depleted shergottites with D > 3 km, especially those in the Tharsis and Elysium volcanic provinces. By excluding the effect of heterogeneous textures across ejecta deposits, which hinder straightforward extraction of superposed production populations, our systematically updated model ages reveal that Chakpar crater at the northern flank of Ascraeus Mons is the best‐fit candidate. The local context of this crater permits establishing a link between the meteorites and specific lava flows. The long‐lived volcanic center here may experience an eruption and/or local deposition hiatus for about 1.8 billion years, and abundant subsurface water existed when the impact occurred at about 1.1 million years. [ABSTRACT FROM AUTHOR]

Monitoring soil water content (SWC) is vital for various applications, particularly in agriculture. This study compares SWC estimated by means of SCATSAR-SWI remote sensing (RS) at different depths (T-values) with Cosmic Ray Neutron Sensing (CRNS) across four agricultural sites in northern Italy. Additionally, it examines the spatial mismatch and representativeness of SWC products' footprints based on different factors within the following areas: the Normalized Difference Vegetation Index (NDVI), soil properties (sand, silt, clay, Soil Organic Carbon (SOC)), and irrigation information. The results reveal that RS-derived SWC, particularly at T = 2 depth, exhibits moderate positive linear correlation (mean Pearson correlation coefficient, R = 0.6) and a mean unbiased Root–Mean–Square Difference (ubRMSD) of 14.90%SR. However, lower agreement is observed during summer and autumn, attributed to factors such as high biomass growth. Sites with less variation in vegetation and soil properties within RS pixels rank better in comparing SWC products. Although a weak correlation (mean R = 0.35) exists between median NDVI differences of footprints and disparities in SWC product performance metrics, the influence of vegetation greenness on the results is clearly identified. Additionally, RS pixels with a lower percentage of sand and SOC and silt loam soil type correlate to decreased agreement between SWC products. Finally, localized irrigation practices also partially explain some differences in the SWC products. Overall, the results highlight how RS pixel variability of the different factors can explain differences between SWC products and how this information should be considered when selecting optimal ground-based measurement locations for remote sensing comparison. [ABSTRACT FROM AUTHOR]

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Background: Flight attendants face various risk factors in their working environments, particularly occupational exposure to cosmic radiation. This study aimed to assess cancer risk among air transportation industry workers, including flight attendants, in Korea by constructing a cohort using national health registry-based data and analyzing cancer incidence risk. Methods: We used the Korea National Health Insurance Service database from 2002 to 2021 to construct a cohort of 37,011 workers in the air transportation industry. Cancer incidence was defined using the tenth version of the International Classification of Diseases. We calculated the age- and sex-specific standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) by applying the cancer incidence rate of the general population between 2002 and 2019. Results: Approximately 5% of the cohort developed cancer. Overall, the cancer incidence in the cohort was similar to or lower than that of the general population, with the SIRs for all cancers being lower. However, significantly higher SIRs were observed for nasopharyngeal cancer (SIR, 3.21; 95% CI, 1.71–5.48) and non-Hodgkin lymphoma (SIR, 1.57; 95% CI, 1.02–2.32) in male workers and breast and genital cancer (SIR, 1.51; 95% CI, 1.34–1.70) and thyroid cancer (SIR, 1.25; 95% CI, 1.05–1.47) in female workers. Conclusions: The lower overall cancer incidence among air transportation industry workers observed in this study could indicate the "healthy worker effect"; however, the incidences of certain cancers were higher than those in the general population. Given that these workers are exposed to multiple occupational and lifestyle-related risk factors, including cosmic radiation, further studies are necessary to determine radiation-induced cancer risk while considering potential confounding factors. [ABSTRACT FROM AUTHOR]

The Scibar Cosmic-Ray Telescope (SciCRT) is the most promising detector of the Sierra Negra Cosmic Rays Observatory (SN-CRO). At this location, being a target and a tracker of secondary cosmic rays, the SciCRT offers a high probability of observing solar energetic particles and lower energy galactic cosmic rays (LEGCR); also, it allows the identification of incoming particles by measuring their energy deposition. In this work we present a Geant4-based simulation of the energy deposited by neutrons, γ -rays, protons, electrons and muons in the optimally running SciCRT components. We also calculated the detection efficiency of the SciCRT at its current state. Our simulation results provide new information about the SciCRT detection response that may be used as a basis to estimate and analyze the energy spectra of primary particles. [ABSTRACT FROM AUTHOR]

The CMS detector, including its muon system, has been operating at the CERN LHC in increasingly challenging conditions for about 15 years. The muon detector was designed to provide excellent triggering and track reconstruction for muons produced in proton–proton collisons at an instantaneous luminosity (L ) of 1 × 10 34 cm - 2 s - 1 . During the Run 2 data-taking period (2015–2018), the LHC achieved an instantaneous luminosity of twice its design value, resulting in larger background rates and making the efficient detection of muons more difficult. While some backgrounds result from natural radioactivity, cosmic rays, and interactions of the circulating protons with residual gas in the beam pipe, the dominant source of background hits in the muon system arises from proton–proton interactions themselves. Charged hadrons leaving the calorimeters produce energy deposits in the muon chambers. In addition, high-energy particles interacting in the hadron calorimeter and forward shielding elements generate thermal neutrons, which leak out of the calorimeter and shielding structures, filling the CMS cavern. We describe the method used to measure the background rates in the various muon subsystems. These rates, in conjunction with simulations, can be used to estimate the expected backgrounds in the High-Luminosity LHC. This machine will run for at least 10 years starting in 2029 reaching an instantaneous luminosity of L = 5 × 10 34 cm -2 s -1 and increasing ultimately to L = 7.5 × 10 34 cm -2 s -1 . These background estimates have been a key ingredient for the planning and design of the muon detector upgrade. [ABSTRACT FROM AUTHOR]

Low-magnitude (FD(%) ≥ − 3 % ) Forbush decreases (FDs) and their space weather linkages are recently becoming popular in the literature. Accurate timing and correct magnitude measurement of weak FDs are a desideratum. This demands disentangling the effects of the ever present cosmic ray (CR) diurnal wave that exerts undesirable influence on CR data. An enhanced version of a recently developed algorithm has been deployed to decompose raw CR data at Apatity (APTY) and Moscow (MOSC) neutron monitor (NM) stations into low and high frequency signals. A subroutine in the Fast Fourier transform software simultaneously calculates the magnitude and the epoch time of the events from the transformed data. The software selected 335 and 359 low magnitude FDs respectively for APTY and MOSC observatories. The large catalogues of low-amplitude FDs selected compared to those in literature may be attributed to the efficiency of the present algorithm. We carried out a regression analysis on the magnitude of these events and the corresponding solar wind disturbance agents. The analysis shows that for the APTY NM station, the correlation coefficient results r for FD-interplanetary magnetic field (IMF) and FD-planetary geomagnetic activity index (ap) relations are statistically significant at 95% confidence level. At the MOSC station, we find r ∼ −0.41 statistically significant at 95% confidence level for FD-solar wind speed (SWS) relation (after removing events due to co-rotating interaction regions). Analyzing all (low- and high-amplitude) FDs, r is relatively strong and statistically significant at 95% confidence level. The implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

This study investigated the relationship between the cosmic ray intensity (CRI) and the horizontal component of Earth's magnetic field (dH) during two intense geomagnetic storms that occurred on September 8, 2017, and August 26, 2018, and a moderate storm on February 18, 2020 over three stations: IRKT, YKTK, and HRMS. The findings of this study indicate that the CRI and dH do not exhibit a simple association over each station. A significant decrease in CRI and dH was seen during the intense geomagnetic storm on September 8, 2017, over all stations as compared to the other two storm events. The decrease was more pronounced over the YKTK station, which has low cutoff rigidity (1.65 GV), than the HRMS (4.58 GV) and IRKT (3.64 GV) stations with high cutoff rigidity. Furthermore, the cross-wavelet analysis reveals that the relationship between CRI and dH varies with the strength of the storm, the location, and the cutoff rigidity of the station. [ABSTRACT FROM AUTHOR]

A novel tool utilizing machine learning techniques was designed to forecast ap index values for the next three consecutive days (24 values). The tool employs time series data from the 3 h ap index of solar cycles 23 and 24 to train the Long Short-Term Memory (LSTM) model, predicting ap index values for the next 72 h at three-hour intervals. During periods of quiet geomagnetic activity, the LSTM model's performance is sufficient to yield favorable outcomes. Nevertheless, during geomagnetically disturbed conditions, such as geomagnetic storms of different levels, the model needs to be adapted in order to provide accurate ap index results. In particular, when coronal mass ejections occur, the ap Prediction tool is modulated by inserting predominant features of coronal mass ejections such as the date of the event, the estimated time of arrival and the linear speed. In the present work, this tool is described thoroughly; moreover, results for G2 and G3 geomagnetic storms are presented. [ABSTRACT FROM AUTHOR]

The Latin American Giant Observatory (LAGO) is a ground-based extended cosmic rays observatory designed to study transient astrophysical events, the role of the atmosphere on the formation of secondary particles, and space-weather-related phenomena. With the use of a network of Water Cherenkov Detectors (WCDs), LAGO measures the secondary particle flux, a consequence of the interaction of astroparticles impinging on the atmosphere of Earth. This flux can be grouped into three distinct basic constituents: electromagnetic, muonic, and hadronic components. When a particle enters a WCD, it generates a measurable signal characterized by unique features correlating to the particle's type and the detector's specific response. The resulting charge histograms from these signals provide valuable insights into the flux of primary astroparticles and their key characteristics. However, these data are insufficient to effectively distinguish between the contributions of different secondary particles. In this work, we extend our previous research by using detailed simulations of the expected atmospheric response to the primary flux and the corresponding response of our WCDs to atmospheric radiation. This dataset, which was created through the combination of the outputs of the ARTI and Meiga simulation frameworks, simulated the expected WCD signals produced by the flux of secondary particles during one day at the LAGO site in Bariloche, Argentina, situated at 865 m above sea level. This was achieved by analyzing the real-time magnetospheric and local atmospheric conditions for February and March of 2012, where the resultant atmospheric secondary-particle flux was integrated into a specific Meiga application featuring a comprehensive Geant4 model of the WCD at this LAGO location. The final output was modified for effective integration into our machine-learning pipeline. With an implementation of Ordering Points to Identify the Clustering Structure (OPTICS), a density-based clustering algorithm used to identify patterns in data collected by a single WCD, we have further refined our approach to implement a method that categorizes particle groups using advanced unsupervised machine learning techniques. This allowed for the differentiation among particle types and utilized the detector's nuanced response to each, thus pinpointing the principal contributors within each group. Our analysis has demonstrated that applying our enhanced methodology can accurately identify the originating particles with a high degree of confidence on a single-pulse basis, highlighting its precision and reliability. These promising results suggest the feasibility of future implementations of machine-leaning-based models throughout LAGO's distributed detection network and other astroparticle observatories for semi-automated, onboard and real-time data analysis. [ABSTRACT FROM AUTHOR]

Galactic winds shape the stellar, gas, and metal content of galaxies. To quantify their impact, we must understand their physics. We review potential wind-driving mechanisms and observed wind properties, with a focus on the warm ionized and hot X-ray-emitting gas. Energy and momentum injection by supernovae (SNe), cosmic rays, radiation pressure, and magnetic fields are considered in the light of observations: Emission and absorption line measurements of cool/warm gas provide our best physical diagnostics of galactic outflows. The critical unsolved problem is how to accelerate cool gas to the high velocities observed. Although conclusive evidence for no one mechanism exists, the momentum, energy, and mass-loading budgets observed compare well with theory. A model in which star formation provides a force ∼L/c, where L is the bolometric luminosity, and cool gas is pushed out of the galaxy's gravitational potential, compares well with available data. The wind power is ∼0.1 of that provided by SNe. The very hot X-ray-emitting phase may be a (or the) prime mover. Momentum and energy exchange between the hot and cooler phases is critical to the gas dynamics. Gaps in our observational knowledge include the hot gas kinematics and the size and structure of the outflows probed with UV absorption lines. Simulations are needed to more fully understand mixing, cloud–radiation, cloud–cosmic ray, andcloud–hot wind interactions, the collective effects of star clusters, and both distributed andclustered SNe. Observational works should seek secondary correlations in the wind data thatprovide evidence for specific mechanisms and compare spectroscopy with the column density–velocity results from theory. [ABSTRACT FROM AUTHOR]

Cosmic radiation experienced during space travel may increase the risk of cognitive impairment. While simulated galactic cosmic radiation (GCRsim) has led to memory deficits in wildtype (WT) mice, it has not been investigated whether GCRsim in combination with genetic risk factors for Alzheimer's disease (AD) worsens memory further in aging mice. Here, we investigated the central nervous system (CNS) effects of 0 Gy (sham) or 0.75 Gy five-ion GCRsim or 2 Gy gamma radiation (IRR) in 14-month-old female and male APPNL-F/NL-F knock-in (KI) mice bearing humanized ApoE3 or ApoE4 (APP;E3F and APP;E4F). As travel to a specialized facility was required for irradiation, both traveled sham-irradiated C57BL/6J WT and KI mice and non-traveled (NT) KI mice acted as controls for potential effects of travel. Mice underwent four behavioral tests at 20 months of age and were euthanized for pathological and biochemical analyses 1 month later. Fecal samples were collected pre- and post-irradiation at four different time points. GCRsim seemed to impair memory in male APP;E3F mice compared to their sham counterparts. Travel tended to improve cognition in male APP;E3F mice and lowered total Aβ in female and male APP;E3F mice compared to their non-traveled counterparts. Sham-irradiated male APP;E4F mice accumulated more fibrillar amyloid than their APP;E3F counterparts. Radiation exposure had only modest effects on behavior and brain changes, but travel-, sex-, and genotype-specific effects were seen. Irradiated mice had immediate and long-term differences in their gut bacterial composition that correlated to Alzheimer's disease phenotypes. [ABSTRACT FROM AUTHOR]

Cosmic ray acceleration at the termination shock of compact star clusters has recently received much attention, mainly because of the detection of gamma-ray emission from some of such astrophysical sources. Here we focus on the acceleration of nuclei at the termination shock and we investigate the role played by proton energy losses and spallation reactions of nuclei, especially downstream of the shock. We show that for a reasonable choice of the mean gas density in the cavity excavated by the cluster wind, dominated by the presence of dense clouds, the spectrum of He nuclei escaping the bubble is systematically harder than the spectrum of hydrogen, in a manner that appears to be qualitatively consistent with the observed and yet unexplained phenomenon of discrepant hardening. We also find that, in this scenario, the spallation reactions of heavier nuclei are likely to be so severe that their spectra becomes very hard and with a low normalization, meaning that it is unlikely that heavy nuclei escaping star clusters can provide a sizeable contribution to the spectrum of cosmic rays at the Earth. Limitations and implications of this scenario are discussed. [ABSTRACT FROM AUTHOR]

While the data analysis of γ-ray telescopes has now become more robust, some signals may be misinterpretations of a time-variable foreground emission from the Solar system, induced by low-energy cosmic-ray interactions with asteroids. Our goal is to provide emission templates for this time-variable diffuse γ-ray foreground by considering the populations of Main Belt Asteroids, Jovian and Neptunian Trojans, Kuiper Belt Objects, and the Oort Cloud. We model the spatial distribution of all known asteroids by performing 3D-fits to determine their density profiles and calculate their appearances by line-of-sight integrations. Because Earth and the asteroids are moving with respect to each other, we obtain diffuse emission templates varying on time-scales of days to decades. We find that the temporal variability can lead to flux enhancements that may mimic emission features unless properly taken into account. This variation is further enhanced by the Solar cycle as the cosmic-ray spectrum is attenuated by the Solar modulation potential, leading to a relative flux increase of the outer asteroids. The cumulative effect of the time-dependent emission is illustrated for the case of the '511 keV OSSE fountain', and for emission features near the Galactic Centre, both being possible misinterpretations of the Solar system albedo. We recommend that γ-ray data analyses should always take into account the possibility of a time-variable foreground. Due to the ecliptic overlap with the Galactic plane, the Galactic emission is expected to be weaker by 0.1–20 per cent, depending on time (relative planetary motion), energy, and Solar cycle, which has consequences for the interpretation of dark matter annihilation cross sections, cosmic-ray spectra and amplitudes, as well as nucleosynthesis yields and related parameters. [ABSTRACT FROM AUTHOR]

This paper employs network theory, mining data and bibliometric analysis when mapping the scientific contribution of Nobel Prize candidate; Manuel Sandoval Vallarta, the first and most renowned Mexican physicist and important figure in Latin American science. Vallarta died in 1977, and the existing literature is about his life and contributions to science but not about how those are still valuable today. This paper is the first to highlight, with mapping tools, that his contributions are relevant to the international community of cosmic rays (as he was pioneer and leader), quantum mechanics and relativity. These tools delivered three findings: Identify how he built his own field of study, same as universal knowledge. Unveil that the backward and forward Vallarta citations follow a scale-free network distribution. Determine social factors that benefited or affected his scientific activities—such as World War II interrupting Vallarta's successful productivity at Massachusetts Institute of Technology. Furthermore, this study confirmed the interdisciplinary nature of the mapping studies of the scientist's contributions using scientometric tools. As a result, several interesting questions arose throughout our research, some of which were answered from the history and philosophy of science. However, others need to be analyzed by experts in the fields of Vallarta. Mapping research sends an invitation to interdisciplinary dialogue/research between experts in different areas of study to better understand the process of knowledge production both, individual and collective. [ABSTRACT FROM AUTHOR]

To study EAS cores (beams of most energetic particles near the shower axis) at E0 ≳ 1015 eV (√s ≳ 2 TeV), which carry the most valuable information about the types of primary particles and the characteristics of their interactions in the atmosphere, a new set of detectors has been developed, including a high-altitude ionization calorimeter "ADRON-55", located at a high-altitude scientific station on the Tien Shan. The first results of modeling the development of EAS from primary protons, main groups of nuclei and hypothetical strangelets at various energies, related to measurements with the "ADRON-55" calorimeter, are presented. [ABSTRACT FROM AUTHOR]

Any Geiger counter can be used as an effective cosmic ray detector on its own. In fact, it is known that even in the absence of a radioactive source, the instrument detects what is known as background radiation, which consists of various types of ionizing particles present in the environment. Remarkably, it is estimated that up to 15% of this background radiation is attributable to cosmic rays, high-energy particles originating from outer space. The remaining radiation detected by the Geiger counter originates from terrestrial sources, such as natural radioactivity in the ground and in the air. The main goal of this project is to build a muon detector for scientific and educational purposes using two commercial DIY Geiger counter kits and just a few additional components. To identify cosmic radiation from terrestrial radiation and improve the accuracy of cosmic ray measurements, the use of a coincident circuit is essential. This coincident circuit was introduced in cosmic ray physics by Walther Bothe and Bruno Rossi in the early 1930s and allows for the detection of a subatomic particle passing through two or more sensors, thereby reducing false positives and enhancing the reliability of cosmic ray detection. The following idea is an alternative replica of our AMD5 detectors, instruments that we have been using for years to teach and perform scientific experiments in the cosmic ray field under the umbrella of the ADA project (2023 Particles, Arcani et al.). The resulting device, named AMD5ALI, offers a reliable and inexpensive solution for the same goal, making it a valuable tool for both educational purposes and scientific surveys. Practical applications range from cosmic ray physics to radioactivity, including the relationship between cosmic ray flux and meteorology, the zenithal effect, the Regener–Pfotzer curve in the atmosphere, and the anti-correlation of cosmic particle intensity with solar activity. [ABSTRACT FROM AUTHOR]

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements and provide comparisons to detector simulations. [ABSTRACT FROM AUTHOR]

A Ground Level Enhancement (GLE) event can be observed as an increase in the background of ground‐based neutron monitor observations and is often associated with an increase of >500 MeV space‐based proton flux measurements. GLE events begin as very high‐energy SEP events associated with GeV protons. For such events to be detected at sea level, proton energies must exceed about 433 MeV. Since the increased flux of such particles can be a major problem to technology in space and on Earth and pose a threat for human health, developing real time warning systems is of great importance. GLE Alert++ is a product, built by the Athens Cosmic Ray Group of the National and Kapodistrian University of Athens, that issues alerts when a GLE event starts to register and is based on ground‐based neutron monitor observations. From the space‐based approach, the HESPERIA UMASEP‐500 product, jointly developed within the framework of the EU HORIZON2020 HESPERIA project by the Universidad de Malaga, Spain and National Observatory of Athens, Greece, provides forecasts of GLE events and >500 MeV protons relying on GOES satellite Soft X‐Ray and high energy proton observations. These two products are fully integrated as federated products on the ESA SWE Portal and are provided as part of the ESA Space Safety Program Space Weather Service Network. In this paper we present how the products were built, provide examples of their outputs as seen on the ESA SWE Portal, and show how the products complement each other and how using them together can in some instances provide more information for users of these services. Plain Language Summary: High‐energy solar energetic particle events contribute to the characterization of the space environment and in extreme cases their effects can be registered on Earth. A Ground Level Enhancement (GLE) event can be observed as an increase in the background of ground‐based neutron monitor observations and is often associated with an increase of >500 MeV space‐based proton flux measurements. Such particles can have potential impacts on space systems, avionics and human health. Therefore, space‐based and ground‐based monitoring of these particles is essential, and so is having reliable real‐time warning systems. In this paper we present two space weather products that have been built for this purpose: (a) GLE Alert++, built by the Athens Cosmic Ray Group of the National and Kapodistrian University of Athens, issues alerts when a GLE event has been registered and is based on ground‐based neutron monitor observations., (b) EU HORIZON2020 HESPERIA UMASEP‐500 provides forecasts of GLE events and >500 MeV protons relying on GOES satellite Soft X‐Ray and high‐energy proton observations. HESPERIA UMASEP‐500 and GLE Alert++, available on the ESA SWE Portal, complement each other and provide space weather users with valuable added advance warnings minutes before and trustworthy alerts during GLE events. Key Points: Ground Level Enhancement (GLE) Alert++ issues alerts when a GLE event starts to register and is based on ground‐based neutron monitor observationsHESPERIA UMASEP‐500 provides forecasts of GLE events and >500 MeV protons relying on Soft X‐Ray and high‐energy proton observationsHESPERIA UMASEP‐500 and GLE Alert++ are complementary tools that enhance space weather forecasting capabilities [ABSTRACT FROM AUTHOR]

Northwest Africa (NWA) 12384 is a lunar polymict breccia composed almost entirely of basaltic components. The clast content includes low‐ to very‐low‐Ti volcanic picritic glass, basaltic vitrophyre, and crystalline pigeonite basalt—an assemblage of volcanic materials that can be tested for petrogenetic relationships. We present the inferred history of select mare components of NWA 12384 as suggested by texture, mineralogy, and petrography, and compare them to Apollo samples and other lunar meteorites. In addition, we used the volcanic glasses in the breccia as a primary composition for crystallization modeling and comparison to the lithic clast compositions. We find that the mafic clasts in NWA 12384 cannot be derived from the picritic glass through a common liquid line of descent because of higher Ti content, though they may have crystallized from a separate, common liquid line of descent. These clasts could represent local source‐region heterogeneity or differential assimilation of more Ti‐rich material. Pb‐Pb SIMS analyses of a large basalt clast in NWA 12384 reveal an age of 3044 ± 41 Ma (2σ), which is used together with the chemical data and 4π cosmic ray exposure age of less than 20 kyr and terrestrial age of between 3.1 and 17.3 kyr to constrain the possible locations of provenance for this meteorite. [ABSTRACT FROM AUTHOR]

Since the 1990s, analysis of cosmogenic nuclides, primarily 10Be, in quartz-bearing river sand, has allowed for quantitative determination of erosion rates at a basin scale. Paired measurements of in situ cosmogenic 26Al and 10Be in sediment are less common but offers insight into the history of riverine sediment moving down slopes and through drainage basins. Prolonged sediment burial (>105 years), a violation of assumptions underlying erosion rate calculations, is indicated by higher 26Al-based than 10Be-based erosion rates due to preferential loss of shorter-lived 26Al by decay when quartz is shielded from cosmic rays. Here, we use a global compilation of 26Al and 10Be data generated from quartz-bearing fluvial sediment samples (n = 624, including 121 new measurements) and calculate the discordance between erosion rates derived from each nuclide. We test for correlations between such discordance and topographic metrics for drainage basins, allowing us to infer the likelihood of sediment burial during transport in different geomorphic settings. We find that nearly half of samples (n = 276) exhibit discordance (> 1σ uncertainty) between erosion rates derived from 10Be and 26Al, indicating sediment histories that must include extended burial during residence on hillslopes and/or in the fluvial system after or during initial near-surface exposure. Physical basin parameters such as basin area, slope, and tectonic activity exhibit significant correlation with erosion rate discordance whereas climatic parameters have little correlation. Our analysis suggests that 26Al/10Be erosion rate discordance occurs more regularly in basins larger than 1,000 km2, particularly when such basins have low average slopes and are in tectonically quiescent terrains. Sediment sourced from smaller, steeper basins in tectonically active regions is more likely to have similar 10Be and 26Al erosion rates indicative of limited storage and limited burial during residence in the hillslope and fluvial sediment system. The data and analysis we present demonstrate that paired 26Al and 10Be analyses in detrital fluvial samples can provide a window into watershed processes, elucidating landscape behavior at different spatial scales and allowing a deeper understanding of both sediment routing systems and whether erosion rate assumptions are violated. Large lowland basins are more likely to transport detrital sediment that has experienced prolonged sediment storage and burial either on hillslopes and/or in fluvial networks; thus, erosion rates from such basins are lower limits due to nuclide decay during storage. Conversely, samples from smaller upland basins are more likely to provide reliable erosion rates. [ABSTRACT FROM AUTHOR]

The non-thermal particles escaping from collision-less shocks into the surrounding medium can trigger a non-resonant streaming instability that converts parts of their drift kinetic energy into large amplitude magnetic field perturbations, and promote the confinement and acceleration of high energy cosmic rays. We present simulations of the instability using an hybrid-Particle-in-Cell approach including Monte Carlo collisions, and demonstrate that the development of the non-resonant mode is associated with important ion pressure anisotropies in the background plasma. Depending on the initial conditions, the anisotropies may act on the instability by lowering its growth and trigger secondary micro-instabilities. Introducing collisions with neutrals yield a strong reduction of the magnetic field amplification as predicted by linear fluid theory. In contrast, Coulomb collisions in fully ionized plasmas are found to mitigate the self-generated pressure anisotropies and promote the growth of the magnetic field. [ABSTRACT FROM AUTHOR]

SQM-ISS is a detector that will search from the International Space Station for massive particles possibly present among the cosmic rays. Among them, we mention strange quark matter, Q-Balls, lumps of fermionic exotic compact stars, Primordial Black Holes, mirror matter, Fermi balls, etc. These compact, dense objects would be much heavier than normal nuclei, have velocities of galaxy-bound systems, and would be deeply penetrating. The detector is based on a stack of scintillator and piezoelectric elements which can provide information on both the charge state and mass, with the additional timing information allowing to determine the speed of the particle, searching for particles with velocities of the order of galactic rotation speed (v ≲ 250 km/s). In this work, we describe the apparatus and its observational capabilities. [ABSTRACT FROM AUTHOR]

• 27-day variations of GCR flux according to measurements of AMS-02 and others. • Parameterization of the amplitude-energy spectrum of variations. • Consequences of the force-field model for short-term modulation. This work presents the results of the analysis of 27-day variations in the flux of galactic protons registered by STEREO, SOHO, and AMS-02 in 2015–2016. We calculate variations' amplitude using several different approaches and propose a description of its energy dependence in the range of magnetic rigidity from approximately 0.3 to 100 GV. We also analyse variations of the solar modulation potential, which is the only parameter of force-field model, and consider the possibility of describing the 27-day variations of galactic cosmic rays within the framework of this model. It is shown that rigidity dependence of the 27-day variations amplitude cannot be properly described using this simple approximation. [ABSTRACT FROM AUTHOR]

• Machine learning (ML) techniques were pioneered to analyze non-linear relationships. • Algorithm's predictive power validated ML models, preventing spurious relations. • Recursive feature elimination explored predictor importance. • Presence of non-linear relationships is suggested, advising further investigation. • Acknowledgment of skepticism stresses rigorous analysis for long-term correlations. The Earth's climate is a complex system that can be influenced by various internal and external factors. Previous research has explored the relationship between climate and external forcings such as solar activity and GCR. However, the relations are intricate and intertwined into almost chaotic meteorological measurements. This paper delves deeper into understanding their interactions. GCR flux, Sunspot number (SSN), total solar irradiance (TSI), UV irradiance (UVI), and the Oceanic Niño Index (ONI) are the predictor variables, while total cloud amount (TCA) and low cloud amount (LCA) are the response variables. The analysis begins with standard statistical techniques and continues with multiple regression models including random forest, which is a machine learning (ML) method that can be used for non-linear regression. Subsequently, Recursive Feature Elimination (RFE) is employed to scrutinize the correlation among the predictor parameters. In the ML model, the final 25% of the dataset is held out and tested for validation, so, the predictive power of the algorithm is measured. Both geographical and temporal patterns have been investigated. This study suggests that a non-linear relationship might exist between the parameters, and should be investigated further, particularly in specific regions of the world. [ABSTRACT FROM AUTHOR]

The major challenge of multiscale measurement methods beyond the point scale is their complex interpretation in the light of landscape heterogeneity. For example, methods like cosmic-ray neutron sensing, remote sensing, or hydrogravimetry are all able to provide an integral value on the water storage, representative for their individual measurement volume. A rigorous assessment of their performance is often hindered by the lack of knowledge about the truth at their corresponding scale, given the high complexity and detail of natural landscapes. In this study we suggest a synthetic virtual landscape that allows for an exact definition of all variables of interest and, consequently, constitutes the so-called 'virtual truth' free of knowledge gaps. Such a landscape can be explored in various 'virtual field campaigns' using 'virtual sensors' that mimic the response and characteristics of actual devices. We use dedicated physically-based models to simulate the signal a sensor would receive. These model outputs termed 'virtual observations' can be explored and also allow the reconstruction of water storage, which can then readily be compared to the 'virtual truth'. Insights from this comparison could help to better understand real measurements and their uncertainties, and to challenge accepted knowledge about signal processing and data interpretation. The 'Virtual Joint Field Campaign' is an open collaborative framework for constructing such landscapes. It comprises data and methods to create and combine different compartments of the landscape (e.g. atmosphere, soil, vegetation). The present study demonstrates virtual observations with Cosmic Ray Neutron Sensing, Hydrogravimetry, and Remote Sensing in three exemplary landscapes. It enables unprecedented opportunities for the systematic assessment of the sensor's strengths and weaknesses and even their combined use. [ABSTRACT FROM AUTHOR]

The Spin Physics Detector is an experiment at NICA designed to study the spin structure of the proton and deuteron and the other spin-related phenomena using polarized beams. The collision energy is up to 27 GeV and the luminosity is up to 10 cm s in pp mode. Two scintillator-based detectors, Beam–Beam Counters (BBC), will be installed upstream and downstream the interaction point and will serve as a tool for beam diagnostics including local polarimetry. In this paper, we present the design of the BBC prototype based on the tiles with green WLS and SensL SiPM readout. FERS-5200 is used as the front-end readout system. The amplitude and timing resolutions for different tiles using radioactive source and cosmic rays are obtained. [ABSTRACT FROM AUTHOR]

Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless planets. However, current research on space weathering focuses mainly on the Moon and certain types of asteroids. In particular, the impacts of meteoroids and micrometeoroids, radiation from solar wind/solar flares/cosmic rays, and thermal fatigue due to temperature variations are being studied. Space weathering produces various transformation products such as melted glass, amorphous layers, iron particles, vesicles, and solar wind water. These in turn lead to soil maturation, changes in visible and near-infrared reflectance spectra (weakening of characteristic absorption peaks, decreased reflectance, increased near-infrared slope), and alterations in magnetism (related to small iron particles), collectively termed the "lunar model" of space weathering transformation. Compared to the Moon and asteroids, Mercury has unique spatial environmental characteristics, including more intense meteoroid impacts and solar thermal radiation, as well as a weaker particle radiation environment due to the global distribution of its magnetic field. Therefore, the lunar model of space weathering may not apply to Mercury. Previous studies have extensively explored the effects of micrometeoroid impacts. Hence, this work focuses on the effects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar irradiation. Through the utilization of high-valence state, heavy ion implantation, and vacuum heating simulation experiments, this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite, pyroxene, and olivine on Mercury's surface and compares them to the weathering transformation model of the Moon. The experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe0 directly but can facilitate its formation, while prolonged exposure to solar thermal radiation on Mercury's surface can lead directly to the formation of np-Fe0. Therefore, intense solar thermal radiation is a crucial component of the unique space weathering transformation process on Mercury's surface. [ABSTRACT FROM AUTHOR]

The number of long duration human spaceflights has increased substantially over the past 15 years, leading to the discovery of numerous effects on the CNS. Microgravity results in headward fluid shifts, ventricular expansion, an upward shift of the brain within the skull, and remodelling of grey and white matter. The fluid changes are correlated with changes to perivascular space and spaceflight associated neuro-ocular syndrome. Microgravity alters the vestibular processing of head tilt and results in reduced tactile and proprioceptive inputs during spaceflight. Sensory adaptation is reflected in postflight effects, evident as transient sensorimotor impairment. Another major concern is that galactic cosmic radiation, which spacefarers will be exposed to when going beyond the magnetosphere around Earth, might have a negative effect on CNS function. Research with rodents points to the potential disruptive effects of space radiation on blood–brain barrier integrity and brain structures. More work is needed to understand and mitigate these effects on the CNS before humans travel to Mars, as the flight durations will be longer than anyone has previously experienced. [ABSTRACT FROM AUTHOR]

In the absence of supplementary heat, the radiative cooling of halo gas around massive galaxies (Milky Way mass and above) leads to an excess of cold gas or stars beyond observed levels. Active galactic nucleus jet-induced heating is likely essential, but the specific properties of the jets remain unclear. Our previous work concludes from simulations of a halo with |$10^{14} \,\mathrm{ M}_\odot$| that a successful jet model should have an energy flux comparable to the free-fall energy flux at the cooling radius and should inflate a sufficiently wide cocoon with a long enough cooling time. In this paper, we investigate three jet modes with constant fluxes satisfying the criteria, including high-temperature thermal jets, cosmic ray (CR)-dominant jets, and widely precessing kinetic jets in |$10^{12}-10^{15}\, {\rm M}_{\odot }$| haloes using high-resolution, non-cosmological magnetohydrodynamic simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model, conduction, and viscosity. We find that scaling the jet energy according to the free-fall energy at the cooling radius can successfully suppress the cooling flows and quench galaxies without violating observational constraints. On the contrary, if we scale the energy flux based on the total cooling rate within the cooling radius, strong interstellar medium cooling dominates this scaling, resulting in a jet flux exceeding what is needed. Among the three jet types, the CR-dominant jet is most effective in suppressing cooling flows across all surveyed halo masses due to enhanced CR pressure support. We confirm that the criteria for a successful jet model work across a wider range, encompassing halo masses of |$10^{12}-10^{15} {\rm M_\odot }$|⁠. [ABSTRACT FROM AUTHOR]

We perform a large-scale hydrodynamic simulation of a massive star cluster whose stellar population mimics that of the Cygnus OB2 association. The main-sequence stars are first simulated during 1.6 Myr, until a quasi-stationary state is reached. At this time, the three Wolf–Rayet stars observed in Cygnus OB2 are added to the simulation, which continues to 2 Myr. Using a high-resolution grid in the centre of the domain, we can resolve the most massive stars individually, which allows us to probe the kinetic structures at small (parsec) scales. We find that, although the cluster excavates a spherical 'superbubble' cavity, the stellar population is too loosely distributed to blow a large-scale cluster wind termination shock, and that collective effects from wind–wind interactions are much less efficient than usually assumed. This challenges our understanding of the ultra-high energy emission observed from the region. [ABSTRACT FROM AUTHOR]

We analyse the GeV γ-ray emission from the W3 complex using about 14 years of Pass 8 data recorded by the Fermi Large Area Telescope (Fermi -LAT). We resolve the γ-ray emissions around W3 into two components: an elliptical Gaussian overlapping with the molecular gas and a point-like source near the cluster W3 Main. The pion-bump feature of SED for the elliptical Gaussian together with the better fitting result of pion decay model favour the hadronic origin. We further argue that the cosmic rays (CRs) could originate from the interactions between cluster winds and the shock produced by the SNR HB3. The point-like source positionally coincident with the star cluster W3 Main indicates it may be directly powered by near clusters, while its fainter γ-ray emissions below 10 GeV are possibly due to the shelter from dense gas making the low-energy CRs incapable of penetrating the dense materials. Meanwhile, we cannot rule out that the γ-ray emissions originate from the interaction of accelerated protons in SNR with the ambient gas. [ABSTRACT FROM AUTHOR]

Radio bubbles, ubiquitous features of the intracluster medium around active galactic nuclei, are known to rise buoyantly for multiple scale heights through the intracluster medium (ICM). It is an open question how the bubbles can retain their high-energy cosmic-ray content over such distances. We propose that the enhanced scattering of cosmic rays due to micromirrors generated in the ICM is a viable mechanism for confining the cosmic rays within bubbles and can qualitatively reproduce their morphology. We discuss the observational implications of such a model of cosmic-ray confinement. [ABSTRACT FROM AUTHOR]