Measurements of low-energy, re-entrant albedo protons by the HEPD-01 space-borne detector

Cosmic rays' interactions with the residual atmosphere surrounding the Earth produce a variety of particles, like electrons, positrons, protons, anti -protons, and Helium nuclei that can be observed below the local geomagnetic cutoff. In this work, we present new measurements of downward -going, albedo proton fluxes with kinetic energy in the range similar to 40- similar to 250 MeV, performed by the High -Energy Particle Detector (HEPD-01) on board of the China Seismo-Electromagnetic Satellite - CSES-01 - at an altitude of similar to 500 km. Employing a dedicated trajectory -tracing simulation routine, the protons collected by HEPD-01 are classified into quasi -trapped (QT), long lifetime ( & Agrave;10 s) particles concentrating in the equatorial region of the Earth, and un-trapped (UT), distributed at all latitudes; the latter includes both precipitating short lifetime particles (UT S ) and pseudotrapped long lifetime (UT L ) populations, abundant in the so-called penumbra regions. The temporal trend of re-entrant protons between 2018 and 2022 is also reported, assessing the stability of such population during the data -taking period of HEPD-01; this highlights their independence from the long-term modulating effect of the solar activity

Multispacecraft Observations of Protons and Helium Nuclei in Some Solar Energetic Particle Events toward the Maximum of Cycle 25

The intricate behavior of particle acceleration and transport mechanisms complicates the overall efforts in formulating a comprehensive understanding of solar energetic particle (SEP) events; these efforts include observations of low-energy particles (from tens of keV to hundreds of MeV) by space-borne instruments and measurements by the ground-based neutron monitors of the secondary particles generated in the Earth atmosphere by SEPs in the GeV range. Numerous space-borne missions provided good data on the nature/characteristics of these solar particles in past solar cycles, but more recently-concurrently with the rise toward the maximum of solar cycle 25-the High-Energy Particle Detector (HEPD-01) proved to be well suited for the study of solar physics and space weather. Its nominal 30-300 MeV energy range for protons can enlarge the detection capabilities of solar particles at low Earth orbit, closer to the injection limit of many SEP events. In this work, we characterize three SEP events within the first six months of 2022 through spectral and velocity dispersion analysis, assessing the response of HEPD-01 to >M1 events

The High Energy Particle Detector (HEPD-02) for the second China Seismo-Electromagnetic Satellite (CSES-02)

CSES (China Seismo-Electromagnetic Satellite) is a multi-instrumental scientific space program whose objectives are to investigate the near-Earth electromagnetic, plasma and particle environment and to study the seismo associated disturbances in the ionosphere-magnetosphere transition zone, the anthropogenic electromagnetic noise as well as the natural non-seismic electromagnetic emissions, mainly due to tropospheric activity. In particular, the mission aims at confirming the existence of possible temporal correlations between the occurrence of medium and strong magnitude earthquakes and the observation in space of electromagnetic perturbations, plasma variations and precipitation of bursts of high-energy charged particles from the inner Van Allen belt. The first satellite (CSES-01) was launched on 2018, while a second one (CSES-02) is currently under development and its launch is expected by the end of 2022. As in CSES-01, the suite of instruments on-board CSES-02 will comprise a particle detector (HEPD-02, High-energy Particle Detector) to measure the increase of the electron and proton fluxes due to short-time perturbations of the radiation belts induced by solar, terrestrial or anthropic phenomena in the energy range 3-100 MeV for electrons and 30-200 MeV for protons. HEPD-02 comprises a tracker made of CMOS Monolithic Active Pixel Sensors (MAPS), a double layer of crossed plastic scintillators for trigger and a calorimeter, made of a tower of plastic scintillators and a matrix of inorganic crystals, surrounded by plastic scintillator planes for containment tagging. The main characteristics and performance of HEPD-02 are presented, highlighting the architectural choices made to meet the scientific objectives of the mission

Proton fluxes inside the South Atlantic Anomaly measured by the High-Energy Particle Detector (HEPD) on board the CSES-01 satellite during the 2018-2021 period

Despite notable improvements made in the last decades, the characterization of the near-Earth proton radiation environment is still incomplete, with major uncertainties affecting the description of high-energy particles ( 50 MeV) in the South Atlantic Anomaly (SAA) region. The High Energy Particle Detector (HEPD) on board the China Seismo-Electromagnetic Satellite (CSES 01), launched on February 2018 on a Low-Earth Orbit and with an altitude of about 507 km, is a light and compact payload suitable for measuring electrons (3-100 MeV), protons (30-300 MeV), and light nuclei (up to a few hundreds of MeV) with a high energy resolution and a wide angular acceptance. Thanks to its good identification performance, it can carry out precise and comprehensive measurement of particle fluxes, including angular information. The observations of HEPD could be fundamental not only for space weather purposes, but because they could help set important constraints on trapping and interaction processes in the Earth’s atmosphere and magnetosphere. Furthermore, they enable the testing and validation of current theoretical and empirical models of the inner radiation belt, like the NASA AP9. In this contribution, we report a preliminary analysis of 30 MeV protons detected inside the SAA region between 2018 and 2021

FCC Physics Opportunities: Future Circular Collider Conceptual Design Report Volume 1

We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the synergy and complementarity of the different colliders, which will contribute to a uniquely coherent and ambitious research programme, providing an unmatchable combination of precision and sensitivity to new physics

HE-LHC: The High-Energy Large Hadron Collider: Future Circular Collider Conceptual Design Report Volume 4

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries

FCC-ee: The Lepton Collider: Future Circular Collider Conceptual Design Report Volume 2

In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in the same 100 km tunnel. The scientific capabilities of the integrated FCC programme would serve the worldwide community throughout the 21st century. The FCC study also investigates an LHC energy upgrade, using FCC-hh technology. This document constitutes the second volume of the FCC Conceptual Design Report, devoted to the electron-positron collider FCC-ee. After summarizing the physics discovery opportunities, it presents the accelerator design, performance reach, a staged operation scenario, the underlying technologies, civil engineering, technical infrastructure, and an implementation plan. FCC-ee can be built with today’s technology. Most of the FCC-ee infrastructure could be reused for FCC-hh. Combining concepts from past and present lepton colliders and adding a few novel elements, the FCC-ee design promises outstandingly high luminosity. This will make the FCC-ee a unique precision instrument to study the heaviest known particles (Z, W and H bosons and the top quark), offering great direct and indirect sensitivity to new physics

HE-LHC: The High-Energy Large Hadron Collider

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries

The performance of the High Energy Particle Detector HEPD-02 on board CSES-02 satellite: from simulation to test beam data

CSES (China Seismo-Electromagnetic Satellite) is a sophisticated multi-payload space observatory aimed to the monitoring of the Van Allen Belts dynamics, the study of solar-terrestrial interactions and the extension at low energies of existing Cosmic Ray measurements. The first satellite (CSES-01) is on orbit since February 2018, hosting on board the HEPD-01 particle detector. The second (CSES-02) will be launched during the early 2024, and will carry HEPD-02, a new high energy particle detector. HEPD-02 is optimized to detect charged particles: mostly electrons (3-100 MeV) and protons (30-200 MeV), with good capabilities in the identification of heavier nuclei. The instrument is quite compact (40.36x53.00x38.15 cm3) and presents important upgrades with respect to its predecessor: it will be the first instrument carrying a CMOS pixel tracker in space, designed to reach a ∼ 4 micron resolution; it will mount an electromagnetic calorimeter that includes six of the largest LYSO crystals ever used in space (15x5x2.5 cm3). The full detector has been recently integrated, with an event reconstruction software already in place. A detailed Monte Carlo (MC) simulation was developed and an extensive beam test campaign performed to validate HEPD-02 capabilities in identification and measurement of kinetic energy and arrival direction of incoming particles. In this contribution a synthetic description of the HEPD-02 detector and its main characteristics will be given. The estimation of its scientific performances on MC simulation will be reported, with a particular focus on their assessment with the different beam test acquisitions and atmospheric muon data

Pax genes and organogenesis: Pax9 meets tooth development.

Pax genes encode a family of transcription factors that play key roles during embryogenesis. They are required for the development of a variety of organs including the nervous and muscular system, skeleton, eye, ear, kidney, thymus, and pancreas. Whereas the developmental roles of many of the nine known Pax genes have been analyzed in great detail, a functional analysis of Pax9 has just begun. During mouse embryogenesis, Pax9 exhibits a highly specific expression pattern in derivatives of the foregut endoderm, somites, limb mesenchyme, midbrain, and the cephalic neural crest. In the mandibular arch mesenchyme, the expression of Pax9 marks the prospective sites of tooth development prior to any morphological signs of odontogenesis and is maintained in the developing tooth mesenchyme thereafter. To understand the function of Pax9 during mouse embryogenesis, we recently have created a null allele by gene targeting. Preliminary analyses show that Pax9 is essential for the formation of teeth, and we conclude that Pax9 is required for tooth development to proceed beyond the bud stage. Here, we briefly summarize our current knowledge about Pax genes and introduce Pax9 to the growing family of factors which are involved in tooth development