CD5 – Adverse space weather—the case of high energy Solar Energetic Particle events

Talks

CD5.1 Mon 4/11 12:00-13:00, room Auditorium

Author(s): Monica Laurenza

INAF-IAPS

Abstract: A full characterization of the energetic particle radiation environment at different heliospheric locations is essential to plan any mission profile, because it can be responsible of possible spacecraft and instrument damage, failures, and malfunctions.
The main radiation environment components of the interplanetary and near-Earth environments are galactic c cosmic rays and solar energetic particles, which represent a continuous harmful condition and short-lived hazards, respectively. They also differ in fluxes and energy spectra and in their opposite relation to the solar activity cycle.
Past studies have provided rough estimations of the radiation environment components mainly at L1 and nearEarth-environment by using models and poor or not calibrated data at energies > 100 MeV.
New missions, such as HENON, LISA, ATHENA, are in their conceptual, design, and specification phases and can benefit from new calibrated datasets of high energy particles such as those that will be produced in the framework of the SPEARHEAD (SPEcification, Analysis & Re-calibration of High Energy pArticle Data) project.
Here, it is presented how such datasets can be exploited, e.g., for an accurate assessment of  the radiation environment variations and worst-case scenarios, for developing onboard  SEP forecasting algorithms, and for designing new instruments, in order to prepare the future space missions. 

Author(s): Cristina Consolandi, AMS collaboration

university of hawaii

Abstract: During its 13 years of operations on board the International Space Station, AMS has detected several solar energetic particle (SEP) events produced during M- and X-class flares and fast coronal mass ejections. AMS studied these SEPs at energies up to a few GeV with unprecedented accuracy. These unique features of the observed SEPs including the May 2024 event will be presented.

Author(s): Malte Hörlöck, Bernd Heber, Stefan Jensen, Patrick Kühl, Holger Sierks

Christian-Albrechts-University Kiel; Christian-Albrechts-University Kiel; Christian-Albrechts-University Kiel; Christian-Albrechts-University Kiel; Max Planck Institute for Solar System Research Göttingen

Abstract: High energy protons and Helium in the heliosphere originate from multiple
sources. Solar Energetic Particle events (SEPs), Anomalous Cosmic Rays
(ACRs) and Galactic Cosmic Rays (GCRs) are prominent examples. Their
energy spectra provide insights into acceleration and transportation
processes. The SOlar and Heliospheric Observatory (SOHO) was launched
December 1995 with the Electron Proton Helium INstrument (EPHIN)
measuring protons and Helium from 4 MeV/nuc to 52 MeV/nuc with an
additional open ended integral channel. However, its measuring capability
was reduced due to the loss of two detectors in 1997 and 2017,
respectively. The X-ray telescope Chandra was launched in 1999, carrying another EPHIN. The Chandra EPHIN was operational until 2006. Using Pulse Height Analysis (PHA) data in the integral channel,
we present methods to derive energy spectra for protons up to more than 100
MeV and Helium spectra up to some 250 MeV/nuc. Results for recent events are shown. This study has received funding from the European
Union’s Horizon 2020 research and innovation programme under grant
agreement No. 101004159 (SERPENTINE) and No. 101135044
(SPEARHEAD).

Author(s): Osku Raukunen, Rami Vainio, Miikka Paassilta, Alexander Mishev, Timo Eronen, Mark Dierckxsens, Norma Crosby, Jussi Lehti

ASRO – Aboa Space Research Oy, Turku, Finland; Department of Physics and Astronomy, University of Turku, Finland; Department of Physics and Astronomy, University of Turku, Finland; Space Physics and Astronomy Research Unit, University of Oulu, Finland; Department of Physics and Astronomy, University of Turku, Finland; Royal Belgian Institute for Space Aeronomy, Brussels, Belgium; Royal Belgian Institute for Space Aeronomy, Brussels, Belgium; ASRO – Aboa Space Research Oy, Turku, Finland

Abstract: As part of the Space Weather Service Network of the ESA, the Space Radiation Expert Service Centre (R-ESC), coordinated by the Royal Belgian Institute for Space Aeronomy, provides tools for monitoring, modelling and forecasting particle radiation and its effects on technological and biological systems in the near-Earth environment. The UTU-SEP product suite, developed by an Expert Group consisting of researchers in the University of Turku, ASRO and University of Oulu, includes six products related to high energy solar energetic particles (SEPs): four statistical models and two catalogue/database products.
The statistical model products include tools for modelling proton fluence, proton peak flux, heavy ion fluence and heavy ion peak flux. All models are based on the well-known JPL-methodology, where SEP event occurrence is assumed to be a Poisson process, and the fluence or peak flux is modelled individually for each energy. The proton fluence model utilizes a dataset of ground level enhancement (GLE) and sub-GLE spectra based on ground-based neutron monitor (NM) and space-based satellite observations, and its energy range extends to very high energies (above 1 GeV) without extrapolation. The proton peak flux model is based on re-calibrated GOES/HEPAD observations, and similarly to the proton fluence model, extends without extrapolation to higher energies than other existing models. The heavy ion fluence model and peak flux model are based on SOHO/ERNE observations which have been corrected for high-flux saturation using the SEPEM helium dataset. Unlike other existing heavy ion models, which use abundance ratios in deriving the heavy ion fluences and peak fluxes, the UTU-SEP models are based on distributions of observed fluences and fluxes.
The high-energy solar proton event catalogue provides detailed information about SEP events observed in 55-80 MeV by the SOHO/ERNE between 1996 and 2022. The catalogue includes numerical data, such as onset times for proton and electron events and X-ray flares, proton and electron peak fluxes, proton and oxygen fluences, oxygen-to iron ratios, X-ray flare classes and locations, CME speeds and widths. In addition, proton and X-ray time series, proton and oxygen fluence spectra, and heavy ion mass spectra are provided in graphical format. Finally, the very high energy solar proton event database provides fluence and peak flux spectra of SEP events observed above 300 MeV during solar cycles 22-24. The fluence spectra are based on analyses of satellite and NM measurements, where integral proton fluence spectra were fitted with double power-law functions with additional exponential roll-overs at high energies. As available, time-resolved measurements above several hundred MeVs are very limited, the peak flux spectra are calculated by an energy-dependent scaling of the fluence spectra. Furthermore, time series and flux spectra at 5-minute resolution, based on full inversion of NM measurements, are available for six best-observed GLEs.
The UTU-SEP product suite provides important tools for the space weather community. Examples of its usage include assessing the high-energy radiation environment in space mission design and using the high-energy spectra in radiation dose studies for aviation. This presentation outlines the data analysis and modelling methodologies used in the products.

CD5.2 Tue 5/11 17:30-18:30, room Auditorium

Author(s): Karl-Ludwig Klein

Observatoire de Paris, France

Abstract: The most energetic particles accelerated in solar eruptive events are protons and nuclei of energies above 1 GeV, possibly extending up to several tens of GeV in large events. They are ultimate challenges for the understanding of particle acceleration processes at the Sun, with bearing on astrophysics in general, and relevant to space weather through the creation of enhanced radiation doses in the terrestrial atmosphere. The particles can be observed indirectly by ground-based neutron monitors, which detect secondary particles of the atmospheric cascade of nuclear reactions triggered by the primaries. Musset et al. (2023, JSWSC 13, 15 – https://doi.org/10.1051/swsc/2023016) showed that the time profiles of relativistic particle events detected by neutron monitors, when suitably normalised by their maximum and by the rise time, were of similar shape. This means that the rise time is a basic parameter of the time evolution of relativistic proton acceleration. This may be explained by interplanetary propagation or else by the time evolution of the energy release at the Sun. Musset and colleagues made a first, but inconclusive, attempt to identify correlations with parameters of solar eruptive activity. We pursue this effort by an exhaustive study of the relationship between the rise time of the neutron monitor signatures and particle acceleration at the Sun, traced in particular by the radio emission of energetic electrons, especially microwave gyrosynchrotron emission of mildly relativistic electrons. We discuss these correlations with respect to those with CME speeds and soft X-ray burst parameters, and compare them with published interpretations based on interplanetary transport models.

Author(s): Eleni Lavasa, Jax Lang, Athanassios Papaioannou, R.D. Strauss, Athanassios Kouloumvakos, Anastasios Anastasiadis, I.A. Daglis, Alexander Hillaris, Bernd Heber, Patrick Kuhl

University of Athens, Greece; North West University, South Africa; National Observatory of Athens, Greece; North West University, South Africa; Johns Hopkins University, Applied Physics Laboratory, USA; National Observatory of Athens, Greece; University of Athens, Greece; University of Athens, Greece; Christian-Albrechts-Universität zu Kiel, Germany; Christian-Albrechts-Universität zu Kiel, Germany

Abstract: The transport of solar energetic particles (SEPs) in the 28 Oct 2021 (GLE73) event is studied, with the focus on their longitudinal spread. This was a multi-spacecraft observation of an impressive event, suggesting a wide source and strong longitudinal diffusion, with particles reaching very high energies. SEP data from STEREO A, SolO/HET & SEPT, and SOHO/EPHIN are utilized in the analysis, as well as novel datasets of penetrating proton channels for SolO/HET & SOHO/EPHIN. Numerical simulations of SEP transport in 1D & 2D are performed, with free model parameters optimized to fit the observed time profiles. Physical parameters estimated through the fitting process include the particles’ parallel and perpendicular mean free path, acceleration and escape times, and the size of the injection source. The rigidity dependence of the physical parameters and pitch-angle distributions is especially investigated, and physical implications are discussed.
This work has received funding from the European Union’s Horizon Europe programme through SPEARHEAD project under grant agreement No 101135044

Author(s): Yuta Kato, Kanya Kusano, Chihiro Mitsuda, Yasuhide Ishihara

Fujitsu Limited; Nagoya University; Fujitsu Limited; Fujitsu Limited

Abstract: Fujitsu Ltd. and Nagoya University are jointly researching space weather to ensure the safety of human activities which are expanding to the Moon and Mars (#1). Solar Energetic Particle (SEP) Events, which occur in conjunction with solar flares (SFs) and coronal mass ejections (CMEs), have effects on both humans and space systems.
We are conducting a classification task using Wide Learning, an explainable Artificial Intelligence (AI) developed by Fujitsu Research, to explore the conditions under which SFs are accompanied by SEP Events. Wide Learning, originally developed in the field of Discovery Science and based on emerging pattern mining algorithms, enables us to conduct classification tasks and to search for exhaustive conditions.
We created 57 features from Soft X-ray measurements observed by GOES, remote sensing vector magnetic fields observed by SDO, and the physics-based flare predictive scheme based on the three-dimensional extrapolated magnetic fields of solar active regions developed by Kusano et al. (2020). We classified SFs that meet the condition of SEPs > 10 MeV, > 10 pfu (cm2 s sr) in the NOAA SWPC database during Solar Cycle 24 as positive samples, and all other SFs as negative samples.
Due to the class imbalance of positive/negative samples, we fixed the positive samples and undersampled the negative samples to achieve a 1:3 ratio of positive to negative samples, conducting 10 trials with replacements. Additionally, due to the flare class imbalance of positive/negative samples, we conducted learning and prediction for cases (a) where negative samples were randomly sampled, and (b) where a constant 1:3 ratio of positive to negative samples was maintained for each C, M, and X flare class.
Our model demonstrates a True Skill Statistic (TSS) for the discrimination capability of SEP-positive SFs of approximately 0.7 for case (a), and about 0.4 for case (b). We also identified multiple useful conditions for predicting positive/negative samples, based on numerical ranges and combinations of each feature. In case (a), the X-ray peak intensity emerged as a significant weighted hypothesis for positive examples, while in case (b), the flare duration and flare history emerged as significant weighted hypotheses. For negative examples, combinations of magnetic field features emerged as significant weighted hypotheses.
These results suggest the potential for predicting SEP Event occurrences with step-by-step alerts, and the ability to reference past cases that align with identified conditions. We will discuss the potential for new space weather forecasts using these numerical ranges and combination conditions, as well as the applicability of past similar cases to these hypotheses, and future prospects.

18:15 HESPERIA REleASE+: Improving Solar Proton Event Forecasting by means of Automated Recognition of Type-III Radio Bursts, Arik Posner, Olga Malandraki, Kostas Tziotziou, Michalis Karavolos, Fanis Smanis, Bernd Heber, Henrik Droege, Patrick Kuehl
18:18 The 2022 Feb 15 SEP event at Mars: A synergistic study combining multiple radiation detectors on the Surface and in Orbit of Mars with models, Jian Zhang, Jingnan Guo
18:21 Properties of Solar Energetic Particles with the AMS-02 experiment on the International Space Station, Francesco Faldi, Bruna Bertucci, Nicola Tomassetti, Miguel Reis Orcinha
18:24 Measurements of ultra-relativistic electrons during solar energetic particle events – Results from the Ulysses Kiel Electron Telescope, Bernd Heber, Marlon Köberle, Carlotta Jöhnk, Ludwig Klein
18:27 Future Canadian Missions for Monitoring Solar Energetic Particles: From the Lunar Gateway to Low Earth Orbit, Ian Mann, Robert Fedosejevs, Henry Tiedje, Louis Ozeke, Anant Telikicherla, Bo Yu, Kai Gan, Leonid Olifer, Neil Rowlands, Muhammad Amjad, Salheddine Belhimer, Dwight Caldwell, Ken Smith, David Cullen, David Barona, Greg Enno

Posters

Posters I  Display Tue 5/11 – Wed 6/11, room C1A – Aeminium

Authors in attendance: Tue 5/11 10:15–11:30, 15:15-16:15; Wed 6/11 10:15–11:30

Author(s): Jian Zhang, Jingnan Guo

University of Science and Technology of China; University of Science and Technology of China

Abstract: On 2022 Feb 15, solar eruptions caused one of the most intense solar energetic particle (SEP) flux enhancements observed by multiple spacecraft in Solar Cycle 25. This study focuses on the enhancements of energetic protons flux observed by multiple spacecraft located at orbit or surface of Mars, including NASA’s Mars Science Laboratory (MSL) on the Martian surface, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter, ESA’s ExoMars Trace Gas Orbiter (TGO) and the Chinese Tianwen-1 Mars’s orbiter.

In fact, this SEP event is to-date the largest one seen by each of them. We carry out the first analysis by the Mars Energetic Particle Analyzer (MEPA) instrument on board the Chinese Tianwen-1 spacecraft at Mars’s orbit which also serves to validate the instrument’s capability to measure protons of up to 100 MeV. This is a critical energy range contributing to radiation environment at the vicinity of Mars and compensates the MAVEN SEP proton measurement at energies below 6 MeV.

Combining the orbital MAVEN and MEPA measurements, together with the proton flux at about 300 MeV above Mars’s atmosphere derived from Mars’s surface radiation detected by MSL, we reconstruct the whole event spectrum upto 1 GeV. We further model the event doses at the Mars’s orbit and surface which are then validated against the corresponding dosimetry data. Our study utilizes all available radiation detectors and Mars, advances our understanding of Mars’s radiation environment induced by large SEP events, and emphasizes the necessity of continuous and synergistic radiation monitoring at Mars.

Author(s): Christos Katsavrias, Sigiava Aminalragia-Giamini, Georgia Moutsiana, Afroditi Nasi, Constantinos Papadimitriou, Ingmar Sandberg, Ioannis A. Daglis, Piers Jiggens

SPARC; SPARC; NKUA; NKUA; SPARC; SPARC; NKUA; ESA/ESTEC

Abstract: The interplanetary particle radiation environment is primarily characterized by cosmic rays and solar energetic particle events. Recently, a novel specification solar particle radiation model was developed with the aim to expand upon the ESA Solar Accumulated and Peak Proton and Heavy Ion Radiation Environment (SAPPHIRE) model. The SAPPHIRE-2S model uses the SEPEM Reference Dataset (RDS) and the SEPEM Reference Event List (REL) which were developed primarily for implementation in the SAPPHIRE model. In the framework of the FIRESPELL project, and in order to continue the development of the SAPPHIRE-2S model, we have utilised a number of interplanetary particle datasets to include SEP electron radiation, an important component of SEP events which has not been extensively modelled, as well as low energy protons and helium (approximately in the 0.04-5 MeV energy range). These particles at these energies are relevant to radiation effects and mission specification and in this work we present the data and appropriate pre-processing methods (despiking, cross-calibration, etc.) employed. The final product is a homogeneous dataset for the new electron and low-energy ion component of SEP radiation covering all SEP events defined in the REL spanning the years 1974-2017.
This work has received funding from the European Space Agency under the “Particle Radiation Modelling for Interplanetary Missions Extending to Low Energies (FIRESPELL)” activity under ESA Contract No 4000142510/23/NL/CRS.

Author(s): Bernd Heber, Marlon Köberle, Carlotta Jöhnk, Ludwig Klein

Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; Observatoire de Paris

Abstract: Solar energetic particle (SEP) events are increases of ions and electrons caused
by solar activity namely flares and coronal mass ejections. While the most
energetic ion population is well studied, SEP events accelerating electrons above
20 MeV have only been reported from measurements by ISEE III in the 1980’s
and the Kiel Electron Telescope (KET).
The KET aboard Ulysses launched in 1990 and measured the electron flux in
the energy range from 4 MeV to above 6 GeV. Here we report on observations
of ultra-relativistic electrons and show spectra of electron events during solar
cycle 22 and 23 until the end of 2008. The maximum electron energy exceeded
100 MeV during the August 16, 2001 SEP event.
This study has received funding from the European Union’s Horizon 2020
research and innovation programme under grant agreement No. 101004159
(SPEARHEAD).

Author(s): Yihua Zheng, Christopher J. Mertens, Guillaume P. Gronoff, Maksym Petrenko, Chinwe C. Didigu, Daniel B. Phoenix, Janessa Buhler, Insoo Jun, Joseph I. Minow, Emily M. Willis, Chiu Wiegand, Richard E. Mullinix

NASA Goddard Space Flight Center; NASA Langley Research Center; NASA Langley Research Center; NASA Goddard Space Flight Center; NASA Goddard Space Flight Center/ADNET Systems Inc; NASA Langley Research Center; NASA Kennedy Space Center; Jet Propulsion Laboratory; NASA Langley Research Center; NASA Marshall Space Flight Center; NASA Goddard Space Flight Center; NASA Goddard Space Flight Center

Abstract: The Nowcast of Aerospace Ionizing RAdiation System (NAIRAS) model is composed of coupled physics-based models that transport ionizing radiation through the heliosphere, Earth’s magnetosphere, the neutral atmosphere, and aircraft and spacecraft shielding. The three sources of ionizing radiation included in the model are: (1) the ubiquitous galactic cosmic rays (GCR) originating outside the solar system, (2) solar energetic particles (SEP), including heavy ions, arising from transient solar eruptive storm events, and (3) the radiation belt trapped protons and electrons (TRPE). The transmission of GCR and SEP ions through space includes the dynamical influence of the interplanetary plasma and magnetic field. The NAIRAS model predicts dosimetric quantities and differential and integral flux and fluence quantities for assessing human radiation exposure and single event effects (SEEs) in vehicle electronic systems from the Earth’s surface to the space environment. The recent NAIRAS version 3.0 is running at the Community Coordinated Modelling Center (CCMC), where the model now operates in two modes: (1) real-time global predictions of the atmospheric radiation environment (0-90 km), and (2) run-on-request (RoR) mode which allows the end-user to select a specific time-period for global dosimetric calculations, or to upload an aircraft, balloon, or flight trajectory file to provide predictions of dosimetric and radiation flux quantities along the flight path. NAIRAS calculations of the ionizing radiation environment are shown for various space weather conditions in the atmosphere and in low-Earth orbit (LEO), medium-Earth orbit (MEO), and cislunar orbit. NAIRAS model comparisons with dosimeter measurements are shown for commercial and high-flying aircraft, stratospheric balloons, and various spaceflight platforms. The recent SEP dose forecast development by coupling NAIRAS with UMASEP (Núñez, 2015,2022) has shown promising results. The contributions of SEP heavy ions are not insignificant.

Author(s): Jian Zhang, Jingnan Guo, Mikhail I. Dobynde

University of Science and Technology of China; University of Science and Technology of China; University of Science and Technology of China

Abstract: Solar Energetic Particles (SEP) are one of the major sources of the Martian radiation environment. It is important to understand the SEP-induced Martian radiation environment for future human habitats on Mars. Due to the lack of a global intrinsic magnetic field, Solar Energetic Particles (SEPs) can directly propagate through and interact with its atmosphere before reaching the surface and subsurface of Mars. Mars has many high mountains and low-altitude craters where the atmospheric thickness can be more than 10 times different than one another. The SEP-induced surface radiation level may therefore be very different from one location to another. We thus consider the influence of the atmospheric depths on the Martian radiation levels including the absorbed dose, dose equivalent, and (human-)body effective dose induced by SEPs at varying heights above and below the Martian surface. The state-of-the-art Atmospheric Radiation Interaction Simulator based on GEometry And Tracking Monte-Carlo method has been employed for simulating particle interactions with the Martian atmosphere and terrain. We find that even the thinnest Martian atmosphere reduces radiation dose from that in deep space by at least 65%, and the shielding effect increases for denser atmosphere. Furthermore, we present a method to quickly forecast the SEP-induced radiation in different regions of Mars with different surface pressures.

Author(s): Fan Lei, Fraser Baird, Chris Davis, Ben Clewer, Clive Dyer, Keith Ryden

Surrey Space Centre, University of Surrey; Surrey Space Centre, University of Surrey; Surrey Space Centre, University of Surrey; Surrey Space Centre, University of Surrey; Surrey Space Centre, University of Surrey; Surrey Space Centre, University of Surrey

Abstract: The atmospheric ionization radiation field is the result of the continuous cosmic ray bombardment, and it is dominated by the secondary particles generated in the cascades of interactions of these energetic particles with the atmosphere.  Most models of the atmospheric radiation environment assume the cosmic rays are isotropic, and while this is largely true in the case of galactic cosmic rays, the solar energetic particles are not, particularly in the early phase of a solar particle event.
AniMAIRE is a new model based on the physics behind its precursor model MAIRE+, which we developed for the UK Met Office, but with the additional feature that it can simulate the radiation effects during anisotropic conditions. The model is available on Github and open to members of the community who wish to make their own contributions and improvements to the model.
In this presentation, we will discuss the physics and algorithm the model based on, its design and implementation, and demonstrate its applications to galactic cosmic ray conditions and during ground level enhancement events.

Author(s): Henrik Dröge, Bernd Heber, Patrick Kühl, Olga Malandraki, Arik Posner

Christian-Albrechts-Universität zu Kiel; Christian-Albrechts-Universität zu Kiel; Christian-Albrechts-Universität zu Kiel; National Observatory of Athens; NASA Headquarters, Washington

Abstract: Solar Energetic Particle (SEP) events can pose a significant radiation hazard for human and robotic space exploration activities. Therefore SEP forecasting systems are needed to support operations. The REleASE system (A. Posner, 2007) utilizes the fact that near relativistic electrons (1 MeV electrons have 94% of the speed of light) travel faster than ions (30 MeV protons have 25% of the speed of light) and are always present in hazardous SEP events. Their early arrival can be used to forecast the expected proton flux. Originally REleASE uses real time data from SOHO/EPHIN and ACE/EPAM (HESPERIA/REleASE) near Earth. We adapted the method to STEREO-A/HET and STEREO-A/SEPT to create an operational STEREO/REleASE system. It was validated with ~15 years of historic data and compared to the original system in the period from June to November 2023 when STEREO-A passed the Earth again. It now offers a platform to test further improvements to the method and prepare for the implementation to future missions.
This study has received funding from the National Aeronautics and Space Administration under grant agreement No. TXS0150642 (HESPERIA RELEASE).

Author(s): Francesco Faldi, Bruna Bertucci, Nicola Tomassetti, Miguel Reis Orcinha

University of Perugia; University of perugia; University of Perugia; University of Perugia

Abstract: We present the daily and orbit-resolved (~ 90 min) rigidity spectrum of solar energetic particles (SEP) measured by the AMS-02 experiment in the rigidity interval from 0.6 to 5 GV, together with their temporal variation for the duration of each solar event.
The Alpha Magnetic Spectrometer is a precision spectrometer on the ISS since May 2011, planned to collect data until 2030. The experiment takes advantage of the peculiar environment of the Low Earth Orbit to directly detect primary cosmic rays, as the thin atmosphere and low geomagnetic field intensity allow to detect even relatively low energy particles (100 MeV).
AMS-02 allows us to measure the high end of the SEP spectra, up to the maximum rigidity reached by solar particles, providing a deep insight on these fenomena at unprecedented precision in that rigidity range.
A systematic study of events measured by AMS-02 and a comparison with other measurements will be presented, showing the correlation between the AMS-02 spectra and known solar events, completing the informations collected by AMS-02 with other instruments.

Author(s): Ian Mann, Robert Fedosejevs, Henry Tiedje, Louis Ozeke, Anant Telikicherla, Bo Yu, Kai Gan, Leonid Olifer, Neil Rowlands, Muhammad Amjad, Salheddine Belhimer, Dwight Caldwell, Ken Smith, David Cullen, David Barona, Greg Enno

University of Alberta, Department of Physics, Edmonton, AB, Canada.; University of Alberta, Department of Electrical and Computer Engineering, Edmonton, AB, Canada.; University of Alberta, Department of Electrical and Computer Engineering, Edmonton, AB, Canada.; University of Alberta, Department of Physics, Edmonton, AB, Canada.; University of Alberta, Department of Electrical and Computer Engineering, Edmonton, AB, Canada.; University of Alberta, Department of Electrical and Computer Engineering, Edmonton, AB, Canada.; University of Alberta, Department of Electrical and Computer Engineering, Edmonton, AB, Canada.; University of Alberta, Department of Physics, Edmonton, AB, Canada.; Honeywell Aerospace, Canada.; Honeywell Aerospace, Canada.; Honeywell Aerospace, Canada.; Honeywell Aerospace, Canada.; Honeywell Aerospace, Canada.; University of Alberta, Department of Physics, Edmonton, AB, Canada.; University of Alberta, Department of Physics, Edmonton, AB, Canada.; University of Alberta, Department of Physics, Edmonton, AB, Canada.

Abstract: Modular energetic particle telescope instruments which can monitor solar energetic particles at a range of locations in the heliosphere are currently under development in Canada at the University of Alberta in collaboration with industrial partners at Honeywell Aerospace. This includes for the approved Canadian RADiation Impacts on Climate and Atmospheric Loss Satellite (RADICALS), which is now in development, as well the Canadian Sweeping Energetic Particle Telescope (SWEPT) proposed for flight on the Lunar Gateway.  The RADICALS is a low-Earth orbiting Canadian small satellite mission investigating the transport of space radiation into the atmosphere, its impacts for the Earth’s climate, and for space weather science and applications. Scheduled for launch in late 2026, or earl 2027, the mission will launch into a polar orbit with an integrated payload including two back-to-back look direction High Energy Particle (HEP) telescopes which will monitor energetic protons up to more than 40 MeV.  Using an innovative Thomson spin-stabilized configuration, the satellite will sample the pitch angle distributions in the spin-plane twice per spin. The key measurement of the pitch angle resolved energetic particles, including a resolved loss cone, will allow a detailed assessment of the energetic particle energy input to the atmosphere. By providing direct coverage of the SEP particle precipitation into the polar ionosphere, the RADICALS explorer will assess impacts on space weather-related interruptions to high frequency (HF) radio communications including in relation to aircraft operations in polar regions – such direct polar coverage providing the basis for a proof-of-principle for a new HF radio communication space weather data product. Outside the magnetosphere, the Canadian SWeeping Energetic Particle Telescope (SWEPT) is a particle telescope proposed for flight on the Lunar Gateway with energy coverage upto over 400 MeV. The main objective of SWEPT is to characterize the radiation risks due to SEP and GCR particles in deep space environments. By using an innovative sweeping look direction to determine the angular and energy dependence of the radiation on the Lunar Gateway, the SWEPT can assess the temporally and angularly evolving solar energetic particle (SEP) radiation in the heliosphere, emitted in solar eruptions and accelerated at interplanetary shocks, as well as address the impacts of primary and secondary radiation hazards on the Lunar Gateway. SWEPT will also contribute to the development of effective deep space radiation mitigation strategies, such as those based on the early arrival of solar energetic electrons, in advance of SEP protons, for humans on the lunar surface or in the lunar vicinity. Overall, the SWEPT will represent a niche contribution adding directional monitoring to the data to be provided by the HERMES, ERSA and IDA payloads on the Lunar Gateway. In combination with monitoring inside the magnetosphere, for example as provided by the energetic particle telescopes on the approved Canadian RADICALS mission, this will collectively not only advance our understanding of the energization, evolution, and propagation of SEPs through the Heliosphere and into the inner magnetosphere and ionosphere – but also help to better understand and mitigate against their space weather effects.

Author(s): Cristiana Francisco, Rui Curado Silva, Fernando Pinheiro, Jorge Maia, José Sousa, Gabriel Falcão, Alexandre Trindade, Pedro Póvoa, Pedro Carmo, André Neves, Joana Gonçalves, João Campos, Miguel Ferreira

Centro de Investigação da Terra e do Espaço da Universidade de Coimbra (CITEUC) e LIP – Laboratório de Instrumentação e Física Experimental de Partículas; LIP – Laboratório de Instrumentação e Física Experimental de Partículas; Centro de Investigação da Terra e do Espaço da Universidade de Coimbra (CITEUC); LIP – Laboratório de Instrumentação e Física Experimental de Partículas; LIP – Laboratório de Instrumentação e Física Experimental de Partículas; Departamento de Engenharia Eletrotécnica da Universidade de Coimbra, Portugal; LIP – Laboratório de Instrumentação e Física Experimental de Partículas; LIP – Laboratório de Instrumentação e Física Experimental de Partículas; LIP – Laboratório de Instrumentação e Física Experimental de Partículas; LIP – Laboratório de Instrumentação e Física Experimental de Partículas; LIP – Laboratório de Instrumentação e Física Experimental de Partículas, Departamento de Engenharia Eletrotécnica da Universidade de Coimbra, Portugal; Departamento de Engenharia Informática da Universidade de Coimbra, Portugal; Departamento de Engenharia Informática da Universidade de Coimbra, Portugal

Abstract: Wide-dynamic range monitoring of the near-Earth space radiation environment in satellites is crucial for space radiation research and Space Weather (SW) analysis. Time and spatially correlated measurements in orbit are vital for developing models of geomagnetic and solar activity, particularly for analyzing solar particle events, coronal mass ejections, the interaction of solar radiation and galactic cosmic rays in the magnetosphere, the dynamics of the Earth radiation belts, and forecasting of SW phenomena. This data is also essential for the design and operation of spacecraft and the assessment of radiation effects on aerospace components and electronic devices.
TGF and High-energy astrophysics Observatory for gamma-Rays on board the Space Rider (THOR-SR) is a mission whose scientific payload is composed of a CdTe Stack Detector and Si Particle Tracker. It will address gamma-ray astrophysics, SW, and TGF monitoring. The Si particle tracker will function as both a charged particle telescope for SW and a high-resolution radiation monitor for radiation effects. It consists of the MiniPIX Space device based on the state-of-the-art Timepix3/Timepix2 ASIC chips from CERN equipped with silicon sensors. Two such devices will be accommodated in an orthogonal array to cover with a full wide field-of-view, spectral, and directional tracking resolving power the complex and variable space radiation along the orbit of the Space Rider mission. These devices will map the light (electron) and heavy (proton, ions) charged particle components in terms of particle species, deposited energy, and direction. Importantly, the Space Rider flight should coincide with the solar maximum, predicted for mid-2025 for the current cycle, offering an opportunity to study its effects on the LEO radiation field.
THOR-SR’s two-month space mission addresses three different objectives:
Space Orbital Radiation and SW: The Si Particle Tracker will allow high-precision wide-range measurements of space radiation and SW data in a two-month equatorial orbit.
Radiation Monitoring for both Gamma-ray CdTe Detector and the Space Rider: The mission will analyze radiation effects on the Gamma-ray CdTe Stack performance, and space radiation in LEO and SW.
Technology Demonstration of the first Timepix2 in space: This will validate the performance of the Timepix2 ASIC chips in a space environment, a technology developed by Advacam in Prague, Czechia.
The experiment will launch aboard the Space Rider Field-of-View Locker, which will be placed in LEO by a Vega-C rocket. The initialization phase will begin once the Space Rider reaches a stable LEO. During the flight, the Si Particle Tracker will record orbital and solar particle tracks. If needed, the scientific data sent to the ground station will be analyzed at LIP’s ground station facilities, allowing for real-time tuning of the detector units’ response.
THOR-SR will provide invaluable data on space radiation, contributing to improved SW forecasting and enhanced safety and design of future spacecraft. Validating the Timepix2 technology in space will also pave the way for more advanced radiation detection and monitoring systems in future missions.