A high-granularity telescope system with a large sensitive area and low material budget has been developed for high-energy heavy ion beam tests. The telescope consists of nine layers of silicon microstrip detectors (SSDs), whose performance was validated through a heavy ion beam test at the CERN SPS. A hybrid machine learning algorithm is proposed to address the challenges of nuclear charge measurement with SSDs. The system achieves a spatial resolution of (9(1) mu m and a charge resolution better than 0.16 charge units for nuclei from Z = 1 to Z = 29, with a sensitive area of 8 & times; 8 cm2. This silicon telescope simultaneously achieves good nuclear charge and spatial resolution across the broad charge range with a large active area.

The High Energy cosmic-Radiation Detection (HERD) facility is a dedicated high energy astronomy and particle physics experiment that will operate on the Chinese space station. Its primary objective is to detect high-energy cosmic rays (GeV similar to PeV) and gamma-rays (> 500 MeV). As one of the sub-detectors of HERD, the Plastic Scintillator Detector (PSD) is designed to identify charged particles for gamma-ray detection and is also utilized to measure the charge of cosmic rays. In 2023, our first prototype of PSD was developed and tested at CERN PS and SPS beam. This paper investigates the positional response of the PSD using two reconstruction algorithms: the traditional dual-ended ratio and a deep learning approach based on KAN neural network. We find that the position resolution reconstructed by the deep learning method ranges approximately from 2.1 mm to 10.6 mm 1 sigma), which is significantly superior to that of the traditional method.

In the context of the Pentadimensional Tracking Space Detector project (PTSD), we are currently developing a demonstrator to increase the Technological Readiness Level of LGAD Si-μstrip tracking detectors for applications in space-borne instruments. Low Gain Avalanche Diodes (LGAD) is a consolidated technology developed for particle detectors at colliders which allows for simultaneous and accurate time (<100 ps) and position (∼10μm) resolutions with segmented Si sensors. It is a candidate technology that could enable for the first time 5D tracking (position, charge, and time) in space using LGAD Si-μstrip tracking systems. The intrinsic gain of LGAD sensors may also allow to decrease the sensor thickness while achieving signal yields similar to those of Si-μstrip currently operated in Space. In this contribution, we discuss the ongoing activities for the design, development, and test of a breadboard laboratory model for verification of requirements, functionalities and space qualification of LGAD Si-μstrip devices for 5D tracking in space. We also present the study performed at the Italian Space Agency - Concurrent Engineering Facility (ASI-CEF) addressing the design of a LGAD-tracker flight-demonstrator to be housed in a 6U-XL CubeSat platform. The possible successful operations in space of the demonstrator could confirm the TRL of Si-μstrip LGAD-trackers to 9, making it a viable and available technology for future mission opportunities for charged cosmic-ray and γ-ray instruments.

In the context of the Pentadimensional Tracking Space Detector project (PTSD), we have designed an In-Orbit Demonstrator (IOD) mission to increase the Technological Readiness Level (TRL) of Low Gain Avalanche Diode (LGAD) Si-μstrip tracking detectors for applications in space-borne instruments. The LGAD Si-sensor is a consolidated technology developed for particle detectors at colliders which allows for simultaneous and accurate time (O(10ps)) and position (∼ 10 μm) resolutions with segmented Si sensors. The space-qualification of detectors based on LGAD Si-μstrips with O(100ps) timing capabilities will provide a breakthrough technology for charged particle tracking, enabling unprecedented solutions for future space experiments. LGADs also allow thinner detectors while achieving signal yields similar to those of Si-μstrip sensors currently operating in space, thus opening possible applications for low-material budget γ-ray converter trackers. This document presents the results of a space mission feasibility study performed at the Italian Space Agency - Concurrent Engineering Facility (ASI-CEF), focused on the design of an IOD mission hosting a payload based on a LGAD-tracker instrument. The successful operations of the IOD would increase the TRL of Si-μstrip LGAD-trackers from the level 5 expected to be reached by the PTSD R&D project to level 9, making it a viable and available technology for future mission opportunities based on charged cosmic-ray and γ-ray instruments.

The Alpha Magnetic Spectrometer (AMS) aboard the International Space Station provides high-precision measurements of cosmic-ray nuclei fluxes from charge Z=1 to Z=28 and beyond. With negligible charge confusion from non-interacting nuclei, the precision of nuclei flux measurements is primarily limited by fragmentation backgrounds originating from heavier cosmic rays interacting within detector materials, particularly between tracker Layers 1 and 2 (L1-L2). As AMS extends its measurements to heavier and rarer nuclei, these fragmentation backgrounds become increasingly dominant, necessitating advanced background suppression methods. To address this challenge, we introduce a Multimodal Domain-Adversarial (MDA) neural network designed to effectively suppress these interaction backgrounds. The MDA model fuses heterogeneous data from the silicon tracker and time-of-flight detectors using specialized sub-networks combined via multi-head attention. Crucially, a domain-adversarial training strategy is employed to learn invariant representations, enabling the model, which is trained on Monte Carlo simulations, to be reliably applied to flight data. Using phosphorus (P) as a benchmark, we demonstrate its background suppression capabilities. This approach provides a robust, generalizable framework applicable to the measurement of other rare cosmic-ray nuclei with AMS.

The AMS-02 experiment plans to install a new silicon microstrip tracker layer (Layer-0) on top of the existing detector, increasing the cosmic-ray acceptance by a factor of 3. Layer-0 employs a design in which multiple silicon microstrip detectors (SSDs) are connected in series to form long detector ladders. We present a detailed performance study of the flight-model ladders using a 350 GeV mixed hadron beam at the CERN SPS. The study focuses on the following aspects: (i) the performance of ladders with different numbers of SSDs, for which the intrinsic spatial resolution at normal incidence varies from 9.5 μm to 11.4 μm for ladders composed of 8 to 12 SSDs; (ii) the response consistency for particles impacting on the Head and Tail regions of the ladder; and (iii) the dependence of the detector performance on the particle incidence angle.

A silicon microstrip detector (SSD) has been developed to have state of the art spatial resolution and a large sensitive area under stringent power constraints. The design incorporates three floating strips with their bias resistors inserted between two aluminum readout strips. Beam test measurements with the single sensor confirmed that this configuration achieves a total detection efficiency of 99.8 % and spatial resolution 7.6 μ m for MIPs. A double-η algorithm was developed to optimize hit position reconstruction for this SSD. The design can be adapted for large area silicon detectors.

We present results over an 11-year Solar cycle of cosmic antiprotons based on 1.1×10^{6} events in the rigidity range from 1.00 to 41.9 GV. The p[over ¯] fluxes exhibit distinct properties. The magnitude of the p[over ¯] flux temporal variation is significantly smaller than those of p, e^{-}, and e^{+}. A hysteresis between the p[over ¯] fluxes and the p fluxes is observed, whereas the p[over ¯] and e^{-} fluxes show a linear correlation. With a model-independent analysis, we found a universal relation between the shape of the rigidity spectrum and the magnitude of flux temporal variation over an 11-year Solar cycle for both positively and negatively charged particles. The simultaneous results on p[over ¯] and p, e^{-}, and e^{+} provide unique information for understanding particle transport in the Solar System as a function of mass, charge, and spectral shape.

We report the properties of precision time structures of cosmic nuclei He, Li, Be, B, C, N, and O fluxes over an 11-year solar cycle from May 2011 to November 2022 in the rigidity range from 1.92 to 60.3 GV. The nuclei fluxes show similar but not identical time variations with amplitudes decreasing with increasing rigidity. In particular, below 3.64 GV the Li, Be, and B fluxes, and below 2.15 GV the C, N, and O fluxes, are significantly less affected by solar modulation than the He flux. We observe that these differences in solar modulation are linearly correlated with the differences in the spectral indices of the cosmic nuclei fluxes. This shows, in a model-independent way, that solar modulation of galactic cosmic nuclei depends on their spectral shape. In addition, solar modulation differences due to nuclei velocity dependence on the mass-to-charge ratio (A/Z) are not observed.

The Pentadimensional Tracking Space Detector (PTSD) project aims to develop a demonstrator to increase the Technological Readiness Level (TRL), for space applications, of Low Gain Avalanche Diodes (LGAD) based Si-μstrip tracking detectors. LGAD is a consolidated technology developed for particle detectors at colliders which allows for simultaneous and accurate time (< 100 ps) and position (∼ 10 μm) resolutions with segmented Si sensors. It is a candidate technology that could enable for the first time 4D tracking (position and time) in space. One of the goals of the project is to not only use this innovative technology to add the time measurement capability to the Si-μstrip tracking system of a space detector, but also to keep its consolidated charge measurement capability, therefore enabling 5D tracking in space. The charge measurement, indeed, is generally required by space applications of Si tracking systems although, in the layout currently adopted by particle collider applications, it is not foreseen. In addition, the intrinsic gain of LGAD sensors also allows to decrease the sensor thickness while achieving signal yields similar to those of Si-μstrips currently operated in space. One of the limiting factors towards the realization of large area (single channel area at the level of cm^2) Si sensors is the large input capacitance to be managed by the Front End Electronics (FEE). The PTSD project includes the development and test of a capacitance mitigation strategy for the aforementioned applications. This paper discusses the proposed mitigation strategy and the first results obtained by laboratory measurements.

High granularity 3D calorimeters offer the potential to precisely reconstruct the 3D topology of electromagnetic and hadronic showers originating from isotropic sources. This distinctive capability creates the opportunity for applying reconstruction and analysis methods that could yield additional information compared to those based on the traditional layer-by-layer energy deposit analysis common in particle and astroparticle physics experiments utilizing calorimeters with layer segmentation. In this study, we present a strategy for analyzing the energy deposit in a crystal array calorimeter, utilizing the 3D parametrization of both longitudinal and transversal shapes of showers to implement likelihood tests on single events. While this analysis was developed using the High Energy cosmic Radiation Detector (HERD) calorimeter as a case study, its applicability may extend to any high granularity, homogeneous, isotropic calorimeter employed in particle physics experiments.

The Pentadimensional Tracking Space Detector (PTSD) project aims for developing a demonstrator to increase the Technological Readiness Level (TRL) of Low Gain Avalanche Diodes (LGAD) Si-microstrip tracking detectors. LGAD is a consolidated technology developed for particle detectors at colliders which allows for simultaneous and accurate time (< 100 ps) and position (similar to 10 mu m) resolutions with segmented Si sensors. It is a candidate technology that could enable for the first time 5D tracking (position, charge, and time) in space using LGAD Si-microstrip tracking systems. The intrinsic gain of LGAD sensors also allows to decrease the sensor thickness while achieving signal yields similar to those of Si-microstrips currently operated in space. We discuss the possible applications and breakthrough opportunities in next generation large area cosmic-ray detectors and sub-GeV gamma-ray detectors that could be enabled by LGAD Si-microstrip tracking detectors in space, the activities to increase the TRL of LGAD Si-microstrip tracking detectors, and the design of a cost-effective instrument to be deployed on a CubeSat platform to enable and qualify the operations of LGAD Si-microstrip detectors in space.

The measurement of cosmic rays at energies exceeding 100 TeV per nucleon is crucial for enhancing the understanding of high-energy particle propagation and acceleration models in the Galaxy. HERD is a space-borne calorimetric experiment that aims to extend the current direct measurements of cosmic rays to unexplored energies, such as protons exceeding one PeV. The payload is scheduled to be installed on the Chinese Space Station in 2027. The primary peculiarity of the instrument is its capability to measure particles coming from all directions, with the main detector being a deep, homogeneous, 3D calorimeter. The active elements are read out using two independent systems: one based on wavelength shifter fibers coupled to CMOS cameras, and the other based on photo-diodes read-out with custom front-end electronics. A large calorimeter prototype was tested in 2023 during an extensive beam test campaign at CERN. In this paper, the performance of the calorimeter for high-energy electron beams, as obtained from the photo-diode system data, is presented. The prototype demonstrated excellent performance, e.g., an energy resolution better than 1% for electrons at 250 G e V. A comparison between beam test data and Monte Carlo simulation data is also presented.

The HERD experiment is a future experiment for the direct detection of high-energy cosmic rays and is to be installed on the Chinese space station in 2027. The main objectives of HERD are the first direct measurement of the knee of the cosmic ray spectrum, the extension of electron+positron flux measurement up to tens of TeV, gamma ray astronomy, and the search for indirect signals of dark matter. The main component of the HERD detector is an innovative calorimeter composed of about 7500 LYSO scintillating crystals assembled in a spherical shape. Two independent readout systems of the LYSO scintillation light will be installed on each crystal: the wavelength-shifting fibers system developed by IHEP and the double photodiode readout system developed by INFN and CIEMAT. In order to measure protons in the cosmic ray knee region, we must be able to measure energy release of about 250 TeV in a single crystal. In addition, in order to calibrate the system, we need to measure typical releases of minimum ionizing particles that are about 30 MeV. Thus, the readout systems should have a dynamic range of about 107. In this article, we analyze the development and the performance of the double photodiode readout system. In particular, we show the performance of a prototype readout by the double photodiode system for electromagnetic showers as measured during a beam test carried out at the CERN SPS in October 2021 with high-energy electron beams.

The Italian Space Agency (ASI) and the Italian National Institute for Astrophysics (INAF) funded a project to design and develop an archive prototype for the ASI SPace weather InfraStructure (ASPIS). The project, CAESAR (Comprehensive Space Weather Studies for the ASPIS Prototype Realization) created a prototype aiming at unifying multiple Space Weather (SWE) resources through a flexible and adaptable architecture, allowing scientists to adopt an integrated approach, encompassing the whole chain of phenomena from the Sun to the Earth up to planetary environments. In this contribution we present various aspects and stages of the CAESAR project from its design phase to the final prototype. The definition of a template (metadata schema) to collect metadata or the resources (products) contributed to the prototype and management. The management of those same metadata documents through the development of a dedicated tool (ProSpecT, Product Specification Template, using JSON and JSONForms). The challenges in keeping it updated while helping the research community in providing both data and data description. The definition of a set of constraints to handle datasets and their metadata in an homogenised way (as much as possible), identifying potential common data formats and reference frames to follow a chain of phenomena from the Sun to the interplanetary medium up to Earth or planetary surfaces. The actual design and implementation of the prototype archive, its ingestion system and API considerations. The design and development of a web base graphical user interface to enable science research on top of the prototype archive, as well as the development of a dedicated python module (ASPISpy) for advanced data investigation and easier integration with other community drive software. The automation of documentation of the contributed resources (data collections, software tools, modules) from the machine readable templated documents. All of the above aspects will be presented, highlighting challenges and specific solutions, as well as potential future evolution of the prototype into the actual archive infrastructure for ASPIS.

X. Liu,a,b,∗ O. Adriani, X. H. Bai, Y. L. Bai, T. W. Bao, E. Berti, P. Betti, S. Bottai, W. W. Cao, J. Casaus, f Z. Chen, X. Z. Cui, R. D’Alessandro, Y. W. Dong, V. Formato, J. R. Gao, F. Giovacchini, f R. Li, X. Z. Liang, C. L. Liao, Y. P. Lu, L. W. Lyu, J. Marin, f G. Martinez, f N. Mori, L. Pacini, R. Pillera, C. Pizzolotto, j J. J. Qin, Z. Quan, D. L. Shi, O. Starodubtsev, A. Tiberio, V. Vagelli, M. A. Velasco, f L. D. Venere, B. Wang, J. J. Wang, L. Wang, R. J. Wang, Z. G. Wang, M. Xu, G. Zampa, j N. Zampa, j L. Zhang and J. K. Zheng on behalf of the HERD collaboration (a complete list of authors can be found at the end of the proceedings) Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, China University of Chinese Academy of Sciences, 101408, Beijing, China INFN sezione di Firenze, I-50019 Sesto Fiorentino, Florence, Italy Department of Physics and Astronomy, University of Florence, I-50019 Sesto Fiorentino, Florence, Italy Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, 710119, Xi’an, China f Centro de Investigaciones Energéticas, Medioambientales y Tecnoló gicas (CIEMAT), E-28040, Madrid, Spain INFN Sezione di Roma Tor Vergata, 00133, Roma, Italy INFN Sezione di Bari, 70126, Bari, Italy j INFN Sezione di Trieste, I-34149, Trieste, Italy Agenzia Spaziale Italiana (ASI), I-00133, Roma, Italy INFN Sezione di Perugia, I-06123, Perugia, Italy

We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.

This paper presents the project Comprehensive spAce wEather Studies for the ASPIS prototype Realization (CAESAR), which aims to tackle the relevant aspects of Space Weather (SWE) science and develop a prototype of the scientific data centre for Space Weather of the Italian Space Agency (ASI) called ASPIS (ASI SPace Weather InfraStructure). To this end, CAESAR involves the majority of the SWE Italian community, bringing together 10 Italian institutions as partners, and a total of 92 researchers. The CAESAR approach encompasses the whole chain of phenomena from the Sun to Earth up to planetary environments in a multidisciplinary, comprehensive, and unprecedented way. Detailed and integrated studies are being performed on a number of well-observed “target SWE events”, which exhibit noticeable SWE characteristics from several SWE perspectives. CAESAR investigations synergistically exploit a great variety of different products (datasets, codes, models), both long-standing and novel, that will be made available in the ASPIS prototype: this will consist of a relational database (DB), an interface, and a wiki-like documentation structure. The DB will be accessed through both a Web graphical interface and the ASPIS.py module, i.e., a library of functions in Python, which will be available for download and installation. The ASPIS prototype will unify multiple SWE resources through a flexible and adaptable architecture, and will integrate currently available international SWE assets to foster scientific studies and advance forecasting capabilities.

The project CAESAR (Comprehensive spAce wEather Studies for the ASPIS prototype Realization) is aimed to tackle all the relevant aspects of Space Weather (SWE) and realize the prototype of the scientific data centre for Space Weather of the Italian Space Agency (ASI) called ASPIS (ASI SPace Weather InfraStructure). This contribution is meant to bring attention upon the first steps in the development of the CAESAR prototype for ASPIS and will focus on the activities of the Node 2000 of CAESAR, the set of Work Packages dedicated to the technical design and implementation of the CAESAR ASPIS archive prototype. The product specifications of the intended resources that will form the archive, functional and system requirements gathered as first steps to seed the design of the prototype infrastructure, and evaluation of existing frameworks, tools and standards, will be presented as well as the status of the project in its initial stage.

The International Space Station (ISS) orbits at an average altitude of 400 km, in the Low Earth Orbit (LEO) and is regularly occupied by astronauts. The material of the Station, the residual atmosphere and the geomagnetic field offer a partial protection against the cosmic radiation to the crew and the equipment. The solar activity can cause sporadic bursts of particles with energies between ∼10 keV and several GeVs called Solar Energetic Particles (SEPs). SEP emissions can last for hours or even days and can represent an actual risk for ISS occupants and equipment. The Alpha Magnetic Spectrometer (AMS) was installed on the ISS in 2011 and is expected to take data until the decommissioning of the Station itself. The instrument detects cosmic rays continuously and can also be used to monitor SEPs in real-time. A detection algorithm developed for the monitoring measures temporary increases in the trigger rates of AMS, using McIlwain’s L-parameter to characterize different conditions of the data-taking environment. A real-time monitor for SEPs has been realized reading data from the AMS Monitoring Interface (AMI) database and processing them using the custom algorithm that was developed.