[ { "id": "authors:pdxtg-n0e58", "collection": "authors", "collection_id": "pdxtg-n0e58", "cite_using_url": "https://authors.library.caltech.edu/records/pdxtg-n0e58", "type": "article", "title": "The High-Energy Ion Telescope (HIT) for the Interstellar Mapping And Acceleration Probe (IMAP) Mission", "author": [ { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937", "clpid": "Christian-E-R" }, { "family_name": "Mitchell", "given_name": "J. G.", "clpid": "Mitchell-J-G" }, { "family_name": "Bruno", "given_name": "A.", "clpid": "Bruno-A" }, { "family_name": "Albaijes", "given_name": "D.", "clpid": "Albaijes-D" }, { "family_name": "Bailey\u00a0Newman", "given_name": "S.", "clpid": "Bailey-Newman-S" }, { "family_name": "Boggs", "given_name": "R. C.", "clpid": "Boggs-R-C" }, { "family_name": "Choi", "given_name": "M. K.", "clpid": "Choi-M-K" }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M" }, { "family_name": "Cook", "given_name": "W. R.", "clpid": "Cook-Walter-Richardson-III" }, { "family_name": "Darwish", "given_name": "Y. S.", "clpid": "Darwish-Y-S" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "de Nolfo", "given_name": "G. A.", "clpid": "de-Nolfo-G-A" }, { "family_name": "Dumonthier", "given_name": "J. J.", "clpid": "Dumonthier-J-J" }, { "family_name": "Garnett", "given_name": "R. D.", "clpid": "Garnett-R-D" }, { "family_name": "Gkioulidou", "given_name": "M.", "clpid": "Gkioulidou-M" }, { "family_name": "Gregory", "given_name": "K. J.", "clpid": "Gregory-K-J" }, { "family_name": "Guzman\u00a0Garcia", "given_name": "D.", "clpid": "Guzman--Garcia-D" }, { "family_name": "Haas", "given_name": "J. P.", "clpid": "Haas-J-P" }, { "family_name": "Hollenhorst", "given_name": "C.", "clpid": "Hollenhorst-C" }, { "family_name": "Jeunon", "given_name": "M.", "clpid": "Jeunon-M" }, { "family_name": "Kaiser", "given_name": "M. A.", "clpid": "Kaiser-M-A" }, { "family_name": "Kanekal", "given_name": "S. G.", "clpid": "Kanekal-S-G" }, { "family_name": "Kecman", "given_name": "B.", "clpid": "Kecman-Branislav" }, { "family_name": "Leske", "given_name": "Richard A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-R-A" }, { "family_name": "Letzer", "given_name": "J. D.", "clpid": "Letzer-J-D" }, { "family_name": "Liceaga\u00a0Indart", "given_name": "I.", "clpid": "Liceaga-Indart-I" }, { "family_name": "McComas", "given_name": "D. J.", "clpid": "McComas-D-J" }, { "family_name": "McNeel", "given_name": "B.", "clpid": "McNeel-B" }, { "family_name": "Muro", "given_name": "G. D.", "orcid": "0000-0003-0581-1278", "clpid": "Muro-Gabriel-D" }, { "family_name": "Nolan", "given_name": "J. T.", "clpid": "Nolan-J-T" }, { "family_name": "Ogindo", "given_name": "M.", "clpid": "Ogindo-M" }, { "family_name": "Petrowich", "given_name": "P.", "clpid": "Petrowich-P" }, { "family_name": "Reaves", "given_name": "W. J.", "clpid": "Reaves-W-J" }, { "family_name": "Rosnack", "given_name": "T. P.", "clpid": "Rosnack-T-P" }, { "family_name": "Saghafi", "given_name": "N.", "clpid": "Saghafi-N" }, { "family_name": "Salerno", "given_name": "C. L.", "clpid": "Salerno-C-L" }, { "family_name": "Schwadron", "given_name": "N. A.", "clpid": "Schwadron-N-A" }, { "family_name": "Silber", "given_name": "M. A.", "clpid": "Silber-M-A" }, { "family_name": "Smith", "given_name": "E. S.", "clpid": "Smith-E-S" }, { "family_name": "Smith", "given_name": "M. T.", "clpid": "Smith-M-T" }, { "family_name": "Su\u00e1rez", "given_name": "G.", "clpid": "Su\u00e1rez-G" }, { "family_name": "Tatoli", "given_name": "T.", "clpid": "Tatoli-T" }, { "family_name": "Tiu", "given_name": "C. P.", "clpid": "Tiu-C-P" }, { "family_name": "Wiedenbeck", "given_name": "Mark Edward", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-M-E" }, { "family_name": "Windhausen", "given_name": "M. H.", "clpid": "Windhausen-M-H" }, { "family_name": "Xu", "given_name": "Z.", "orcid": "0000-0002-9246-996X", "clpid": "Xu-Zigong" } ], "abstract": "

The Interstellar Mapping and Acceleration Probe (IMAP; McComas et al. in Space Sci Rev 214:116, 2018a; McComas et al. in Space Sci Rev 221:100, 2025) is a NASA mission designed to study two of the most important issues in heliophysics: the interaction of the solar wind with the local interstellar medium and the acceleration of energetic particles. These two puzzles are surprisingly intertwined because particle acceleration in the inner heliosphere plays a large role in the interactions at the edge of the heliosphere. The ten instruments on IMAP, situated near the Earth-Sun L1 Lagrange point, include both in situ and remote-sensing observations and are designed to work together to explore these questions. The High-energy Ion Telescope (HIT), described herein, measures in situ ions from hydrogen through nickel at energies ranging from a few MeV/nucleon to some tens of MeV/nucleon, depending upon species. While the primary focus of HIT is Solar Energetic Particles (SEPs), HIT is also sensitive to Anomalous Cosmic Rays (ACRs) and Galactic Cosmic Rays (GCRs) that are also present at these energies. Working with the other IMAP instruments, HIT studies how the variation in SEP intensities, spectra, anisotropies, and composition inform the acceleration processes that generate these particles, and, in turn, how these high-energy particles affect the outer heliosphere. This paper details the design and operation of the HIT instrument.

", "doi": "10.1007/s11214-026-01279-6", "issn": "0038-6308", "publisher": "Springer Science and Business Media LLC", "publication": "Space Science Reviews", "publication_date": "2026-02-27", "volume": "222", "pages": "23" }, { "id": "authors:mxpr2-ssr97", "collection": "authors", "collection_id": "mxpr2-ssr97", "cite_using_url": "https://authors.library.caltech.edu/records/mxpr2-ssr97", "type": "article", "title": "Multi-Species Energy-Banded Ions in the Ionosphere During the 21 January 2005 Magnetic Storm: Low-Altitude Edge of the Warm Plasma Cloak", "author": [ { "family_name": "Kozyra", "given_name": "J. U.", "orcid": "0009-0006-0237-8527" }, { "family_name": "Liemohn", "given_name": "M. W.", "orcid": "0000-0002-7039-2631" }, { "family_name": "Cattell", "given_name": "C. A.", "orcid": "0000-0002-3805-320X" }, { "family_name": "Dombeck", "given_name": "J.", "orcid": "0000-0003-1635-3890" }, { "family_name": "Escoubet", "given_name": "C. P.", "orcid": "0000-0003-4475-6769" }, { "family_name": "Thomsen", "given_name": "M." }, { "family_name": "Lu", "given_name": "G.", "orcid": "0000-0001-5350-2889" }, { "family_name": "Knipp", "given_name": "D. J.", "orcid": "0000-0002-2047-5754" }, { "family_name": "Paxton", "given_name": "L. J.", "orcid": "0000-0002-2597-347X" }, { "family_name": "Skoug", "given_name": "R. M.", "orcid": "0000-0003-1991-2643" }, { "family_name": "Elliott", "given_name": "H. A.", "orcid": "0000-0003-2297-3922" }, { "family_name": "Davis", "given_name": "A. J.", "clpid": "Davis-Andrew-J" }, { "family_name": "Rastaetter", "given_name": "L.", "orcid": "0000-0002-7343-4147" }, { "family_name": "DeZeeuw", "given_name": "D." }, { "family_name": "Colpitts", "given_name": "C.", "orcid": "0000-0001-7457-6537" } ], "abstract": "
\n

During the 21–22 January 2005 magnetic storm, the FAST satellite observed warm (< few keV) ions in discrete energy bands on the dayside at ∼3,000 km altitude for more than 6.5 hr. We suggest that the ionospheric energy-banded ions represent the low-altitude edge of the warm plasma cloak observed simultaneously by magnetospheric satellites. This is a clear example of the multi-species ion energy bands (10 eV to several keV) observed during strong magnetic storms by the FAST satellite, stretching from the diffuse auroral region to the plasmapause with lifetimes up to 12 hr. The close association of these energy-banded ions with magnetic storms, their broad latitudinal extent, and the presence of multiple ion species in the same energy band, rather than at the same velocity, indicate that this is a distinct phenomenon from other types of energy-banded ions. During the 21–22 January 2005 magnetic storm, the dayside ion energy band structures, centered at 10 eV (H+), 40 eV (H+ and He+), and 160 eV (H+, He+, and O+), were consistent with a “time-of-flight and velocity filter” formation process acting on a near-cusp, impulsive outflow of a <200 eV multi-species ion-source population, poleward and in the same hemisphere as FAST. Understanding the sources and dynamics of warm energy-banded ions and their linkage to the warm plasma cloak is important because during superstorms these ions are transported to L values as low as L ∼ 1.2 in the dawn sector, significantly altering the energetics of the mid-latitude ionosphere.

\n
", "doi": "10.1029/2024ja033556", "issn": "2169-9380", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research: Space Physics", "publication_date": "2026-01", "series_number": "1", "volume": "131", "issue": "1", "pages": "e2024JA033556" }, { "id": "authors:ywns3-e6t82", "collection": "authors", "collection_id": "ywns3-e6t82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220307-189632000", "type": "article", "title": "Suprathermal Ion Energy Spectra and Anisotropies near the Heliospheric Current Sheet Crossing Observed by the Parker Solar Probe during Encounter 7", "author": [ { "family_name": "Desai", "given_name": "M. I.", "orcid": "0000-0002-7318-6008", "clpid": "Desai-Mihir-I" }, { "family_name": "Mitchell", "given_name": "D. G.", "orcid": "0000-0003-1960-2119" }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158" }, { "family_name": "Drake", "given_name": "J. F.", "orcid": "0000-0002-9150-1841" }, { "family_name": "Phan", "given_name": "T.", "orcid": "0000-0002-6924-9408" }, { "family_name": "Szalay", "given_name": "J. R.", "orcid": "0000-0003-2685-9801" }, { "family_name": "Roelof", "given_name": "E. C.", "orcid": "0000-0002-2270-0652" }, { "family_name": "Giacalone", "given_name": "J.", "orcid": "0000-0002-0850-4233" }, { "family_name": "Hill", "given_name": "M. E.", "orcid": "0000-0002-5674-4936" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937" }, { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283" }, { "family_name": "McNutt", "given_name": "R. L.", "orcid": "0000-0002-4722-9166" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-M-E" }, { "family_name": "Joyce", "given_name": "C.", "orcid": "0000-0002-3841-5020" }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Krimigis", "given_name": "S. M.", "orcid": "0000-0003-2781-2386" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Matthaeus", "given_name": "W. H.", "orcid": "0000-0001-7224-6024" }, { "family_name": "Malandraki", "given_name": "O.", "orcid": "0000-0002-4751-6835" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Labrador", "given_name": "A.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Bale", "given_name": "S. D.", "orcid": "0000-0002-1989-3596" }, { "family_name": "Verniero", "given_name": "J.", "orcid": "0000-0003-1138-652X" }, { "family_name": "Rahmati", "given_name": "A.", "orcid": "0000-0003-0519-6498" }, { "family_name": "Whittlesey", "given_name": "P.", "orcid": "0000-0002-7287-5098" }, { "family_name": "Livi", "given_name": "R.", "orcid": "0000-0002-0396-0547" }, { "family_name": "Larson", "given_name": "D.", "orcid": "0000-0001-5030-6030" }, { "family_name": "Pulupa", "given_name": "M.", "orcid": "0000-0002-1573-7457" }, { "family_name": "MacDowall", "given_name": "R. J.", "orcid": "0000-0003-3112-4201" }, { "family_name": "Niehof", "given_name": "J. T.", "orcid": "0000-0001-6286-5809" }, { "family_name": "Kasper", "given_name": "J. C.", "orcid": "0000-0002-7077-930X" }, { "family_name": "Horbury", "given_name": "T. S.", "orcid": "0000-0002-7572-4690" } ], "abstract": "We present observations of \u227310\u2013100 keV nucleon\u207b\u00b9 suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances of <0.1 au from the Sun. Our key findings are as follows: (1) very few heavy ions are detected during the first full crossing, the heavy-ion intensities are reduced during the second partial crossing and peak just after the second crossing; (2) ion arrival times exhibit no velocity dispersion; (3) He pitch-angle distributions track the magnetic field polarity reversal and show up to \u223c10:1 anti-sunward, field-aligned flows and beams closer to the HCS that become nearly isotropic farther from the HCS; (4) the He spectrum steepens either side of the HCS, and the He, O, and Fe spectra exhibit power laws of the form \u223cE\u2212\u207b\u2074\u2013E\u2076; and (5) maximum energies EX increase with the ion's charge-to-mass (Q/M) ratio as E_X/E_H \u221d Q_X/M_X^\u03b4, where \u03b4 \u223c 0.65\u20130.76, assuming that the average Q states are similar to those measured in gradual and impulsive solar energetic particle events at 1 au. The absence of velocity dispersion in combination with strong field-aligned anisotropies closer to the HCS appears to rule out solar flares and near-Sun coronal-mass-ejection-driven shocks. These new observations present challenges not only for mechanisms that employ direct parallel electric fields and organize maximum energies according to E/Q but also for local diffusive and magnetic-reconnection-driven acceleration models. Reevaluation of our current understanding of the production and transport of energetic ions is necessary to understand this near-solar, current-sheet-associated population of ST ions.", "doi": "10.3847/1538-4357/ac4961", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-03-01", "series_number": "1", "volume": "927", "issue": "1", "pages": "Art. No. 62" }, { "id": "authors:727mj-dnb25", "collection": "authors", "collection_id": "727mj-dnb25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211214-82643000", "type": "article", "title": "Solar energetic particle heavy ion properties in the widespread event of 2020 November 29", "author": [ { "family_name": "Mason", "given_name": "G. M.", "orcid": "0000-0003-2169-9618", "clpid": "Mason-Glenn-M" }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Ho", "given_name": "G. C.", "orcid": "0000-0003-1093-2066" }, { "family_name": "Mitchell", "given_name": "D. G.", "orcid": "0000-0003-1960-2119" }, { "family_name": "Allen", "given_name": "R. C.", "orcid": "0000-0003-2079-5683" }, { "family_name": "Hill", "given_name": "M. E.", "orcid": "0000-0002-5674-4936" }, { "family_name": "Andrews", "given_name": "G. B." }, { "family_name": "Berger", "given_name": "L." }, { "family_name": "Boden", "given_name": "S." }, { "family_name": "B\u00f6ttcher", "given_name": "S." }, { "family_name": "Cernuda", "given_name": "I." }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Desai", "given_name": "M. I." }, { "family_name": "de Nolfo", "given_name": "G. A.", "orcid": "0000-0002-3677-074X" }, { "family_name": "Eldrum", "given_name": "S." }, { "family_name": "Elftmann", "given_name": "R." }, { "family_name": "Kollhoff", "given_name": "A." }, { "family_name": "Giacalone", "given_name": "J.", "orcid": "0000-0002-0850-4233" }, { "family_name": "G\u00f3mez-Herrero", "given_name": "R." }, { "family_name": "Hayes", "given_name": "J." }, { "family_name": "Janitzek", "given_name": "N. P." }, { "family_name": "Joyce", "given_name": "C. J.", "orcid": "0000-0002-3841-5020" }, { "family_name": "Korth", "given_name": "A." }, { "family_name": "K\u00fchl", "given_name": "P." }, { "family_name": "Kulkarni", "given_name": "S. R." }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Espinosa Lara", "given_name": "F." }, { "family_name": "Lees", "given_name": "W. J." }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Mall", "given_name": "U." }, { "family_name": "Martin", "given_name": "C." }, { "family_name": "Mart\u00ednez Hell\u00edn", "given_name": "A." }, { "family_name": "Matthaeus", "given_name": "W. H.", "orcid": "0000-0001-7224-6024" }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158" }, { "family_name": "McNutt", "given_name": "R. L.", "orcid": "0000-0002-4722-9166" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Mitchell", "given_name": "J. G.", "orcid": "0000-0003-4501-5452" }, { "family_name": "Pacheco", "given_name": "D." }, { "family_name": "Parra Espada", "given_name": "P." }, { "family_name": "Prieto", "given_name": "M." }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444" }, { "family_name": "Ravanbakhsh", "given_name": "A." }, { "family_name": "Rodr\u00edguez-Pacheco", "given_name": "J." }, { "family_name": "Rodr\u00edguez Polo", "given_name": "O." }, { "family_name": "Roelof", "given_name": "E. C.", "orcid": "0000-0002-2270-0652" }, { "family_name": "S\u00e1nchez-Prieto", "given_name": "S." }, { "family_name": "Schlemm", "given_name": "C. E." }, { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283" }, { "family_name": "Seifert", "given_name": "H." }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Szalay", "given_name": "J. R.", "orcid": "0000-0003-2685-9801" }, { "family_name": "Terasa", "given_name": "J. C." }, { "family_name": "Tyagi", "given_name": "K." }, { "family_name": "Freiherr von Forstner", "given_name": "J. L.", "orcid": "0000-0002-1390-4776" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" }, { "family_name": "Wimmer-Schweingruber", "given_name": "R. F." }, { "family_name": "Xu", "given_name": "Z. G." }, { "family_name": "Yedla", "given_name": "M." } ], "abstract": "Context. Following a multi-year minimum of solar activity, a solar energetic particle event on 2020 Nov. 29 was observed by multiple spacecraft covering a wide range of solar longitudes including ACE, the Solar Terrestrial Relations Observatory-A, and the recently launched Parker Solar Probe and Solar Orbiter. \n\nAims. Multi-point observations of a solar particle event, combined with remote-sensing imaging of flaring, shocks, and coronal mass ejections allows for a global picture of the event to be synthesized, and made available to the modeling community to test, constrain, and refine models of particle acceleration and transport according to such parameters as shock geometries and particle mass-to-charge ratios.\nMethods. Detailed measurements of heavy ion intensities, time dependence, fluences, and spectral slopes provided the required test data for this study. \n\nResults. The heavy ion abundances, timing, and spectral forms for this event fall well within the range found in prior surveys at 1 au. The spectra were well fitted by broken power law shapes; the Fe/O ratio was somewhat lower than the average of other events. In addition, \u00b3He/\u2074He was very low, with only the upper limits established here.", "doi": "10.1051/0004-6361/202141310", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-12", "volume": "656", "pages": "Art. No. L12" }, { "id": "authors:tfzan-gfz75", "collection": "authors", "collection_id": "tfzan-gfz75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211214-82701000", "type": "article", "title": "PSP/IS\u2299IS observations of the 29 November 2020 solar energetic particle event", "author": [ { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937", "clpid": "Christian-Eric-R" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Desai", "given_name": "M. I.", "orcid": "0000-0002-7318-6008", "clpid": "Desai-Mihir-I" }, { "family_name": "de Nolfo", "given_name": "G. A.", "orcid": "0000-0002-3677-074X", "clpid": "de-Nolfo-Georgia-A" }, { "family_name": "Giacalone", "given_name": "J.", "orcid": "0000-0002-0850-4233", "clpid": "Giacalone-Joe" }, { "family_name": "Hill", "given_name": "M. E.", "orcid": "0000-0002-5674-4936", "clpid": "Hill-Matthew-E" }, { "family_name": "Joyce", "given_name": "C. J.", "orcid": "0000-0002-3841-5020", "clpid": "Joyce-Colin-J" }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Matthaeus", "given_name": "W. H.", "orcid": "0000-0001-7224-6024", "clpid": "Matthaeus-William-H" }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158", "clpid": "McComas-David-J" }, { "family_name": "McNutt", "given_name": "R. L., Jr.", "orcid": "0000-0002-4722-9166", "clpid": "McNutt-Ralph-L-Jr" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Mitchell", "given_name": "D. G.", "orcid": "0000-0003-1960-2119", "clpid": "Mitchell-Donald-G" }, { "family_name": "Mitchell", "given_name": "J. G.", "orcid": "0000-0003-4501-5452", "clpid": "Mitchell-John-Grant" }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444", "clpid": "Rankin-Jamie-S" }, { "family_name": "Roelof", "given_name": "E. C.", "orcid": "0000-0002-2270-0652", "clpid": "Roelof-Edmond-C" }, { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283", "clpid": "Schwadron-Nathan-A" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Szalay", "given_name": "J. R.", "orcid": "0000-0003-2685-9801", "clpid": "Szalay-Jamey-R" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" }, { "family_name": "Vourlidas", "given_name": "A.", "orcid": "0000-0002-8164-5948", "clpid": "Vourlidas-Angelos" }, { "family_name": "Bale", "given_name": "S. D.", "orcid": "0000-0002-1989-3596", "clpid": "Bale-Stuart-D" }, { "family_name": "Pulupa", "given_name": "M.", "orcid": "0000-0002-1573-7457", "clpid": "Pulupa-Marc" }, { "family_name": "MacDowall", "given_name": "R. J.", "orcid": "0000-0003-3112-4201", "clpid": "MacDowall-Robert-J" } ], "abstract": "Aims. On 29 November 2020, at 12:34 UT, active region 12790 erupted with an M4.4 class flare and a 1700 km s\u207b\u00b9 coronal mass ejection. Parker Solar Probe (PSP) was completing its seventh orbit around the Sun and was located at 0.8 au when the Integrated Science Investigation of the Sun (IS\u2299IS) measured the ensuing mid-sized solar energetic particle (SEP) event. Not only was this the first SEP event with heavy ions above 10 MeV nuc\u207b\u00b9 to be measured by IS\u2299IS, it was also measured by several spacecraft positioned around the Sun, making it the first circumsolar event of solar cycle 25. Here we describe an overview of the SEP event characteristics at PSP. \n\nMethods. Fluence spectra for electrons, H, He, O, and Fe were calculated for the decay portion of the event. For the entire time period of the event, it was possible to calculate fluence spectra for electrons, O, and Fe only due to instrumental mode changes in one of the IS\u2299IS telescopes, affecting H and He during the period of peak intensities. Using higher time resolution data, we also studied the onset of the event and temporal variations in the particle intensities at the shock and during the magnetic cloud passage. \n\nResults. During the decay, the ion spectra are consistent with power laws at low energies with an exponential rollover at a few MeV nuc\u207b\u00b9, while the electron spectrum is consistent with a power law of index \u22125.3. Based on fits to the spectra, Fe/O and He/H abundance ratios as a function of energy are calculated and found to be nominal for large SEP events at hundreds of keV/nuc, but decrease strongly with increasing energy. The full-event spectra for O and Fe have similar shapes to those of the decay, but with higher roll-over energies. The electron spectrum for the full event is harder with an index of \u22123.4 and there is some evidence of higher energy components near \u223c2 MeV and above \u223c4 MeV. Despite the spacecraft being tilted 45\u00b0 with respect to the nominal orientation of the spacecraft's long axis pointed towards the Sun, there is some anisotropy apparent in MeV protons during the onset of the event. Velocity dispersion is also evident, consistent with a solar release time of 13:15 UT and pathlength of 1.3 au. The arrival of the related magnetic cloud resulted in the suppression of SEP intensities, although a brief increase in particle intensities suggests PSP moved out of the cloud for \u223c30 min. This appears to be the first medium-sized event in the rise of cycle 25 activity, with additional large events likely to occur. Additional details of the event beyond this overview can be found in several related papers.", "doi": "10.1051/0004-6361/202140967", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-12", "volume": "656", "pages": "Art. No. A29" }, { "id": "authors:hbkr7-40y56", "collection": "authors", "collection_id": "hbkr7-40y56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210608-133059480", "type": "article", "title": "Parker Solar Probe observations of He/H abundance variations in SEP events inside 0.5 au", "author": [ { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Desai", "given_name": "M. I.", "orcid": "0000-0002-7318-6008" }, { "family_name": "de Nolfo", "given_name": "G. A.", "orcid": "0000-0002-3677-074X" }, { "family_name": "Giacalone", "given_name": "J.", "orcid": "0000-0002-0850-4233" }, { "family_name": "Hill", "given_name": "M. E.", "orcid": "0000-0002-5674-4936" }, { "family_name": "Joyce", "given_name": "C. J.", "orcid": "0000-0002-3841-5020" }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Matthaeus", "given_name": "W. H.", "orcid": "0000-0001-7224-6024" }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158" }, { "family_name": "McNutt", "given_name": "R. L.", "orcid": "0000-0002-4722-9166" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Mitchell", "given_name": "D. G.", "orcid": "0000-0003-1960-2119" }, { "family_name": "Mitchell", "given_name": "J. G.", "orcid": "0000-0003-4501-5452" }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444" }, { "family_name": "Roelof", "given_name": "E. C.", "orcid": "0000-0002-2270-0652" }, { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Szalay", "given_name": "J. R.", "orcid": "0000-0003-2685-9801" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" }, { "family_name": "Vourlidas", "given_name": "A.", "orcid": "0000-0002-8164-5948" }, { "family_name": "Bale", "given_name": "S. D.", "orcid": "0000-0002-1989-3596" }, { "family_name": "Pulupa", "given_name": "M.", "orcid": "0000-0002-1573-7457" }, { "family_name": "MacDowall", "given_name": "R. J.", "orcid": "0000-0003-3112-4201" } ], "abstract": "Aims. The Parker Solar Probe (PSP) orbit provides an opportunity to study the inner heliosphere at distances closer to the Sun than previously possible. Due to the solar minimum conditions, the initial orbits of PSP yielded only a few solar energetic particle (SEP) events for study. Recently during the fifth orbit, at distances from 0.45 to 0.3 au, the energetic particle suite on PSP, Integrated Science Investigation of the Sun (IS\u2299IS), observed a series of six SEP events, adding to the limited number of SEP events studied inside of 0.5 au. Variations in the H and He spectra and the He/H abundance ratio are examined and discussed in relation to the identified solar source regions and activity.\nMethods. IS\u2299IS measures the energetic particle environment from ~20 keV to >100 MeV/nuc. Six events were selected using the ~1 MeV proton intensities, and while small, they were sufficient to calculate proton and helium spectra from ~1 to ~10 MeV/nuc. For the three larger events, the He/H ratio as a function of energy was determined. Using the timing of the associated radio bursts, solar sources were identified for each event and the eruptions were examined in extreme ultraviolet emission.\nResults. The largest of the selected events has peak ~1 MeV proton intensities of 3.75 (cm\u00b2 sr s MeV)\u207b\u00b9. Within uncertainties, the He and H spectra have similar power law forms with indices ranging from \u22122.3 to \u22123.3. For the three largest events, the He/H ratios are found to be relatively energy independent; however, the ratios differ substantially with values of 0.0033 \u00b1 0.0013, 0.177 \u00b1 0.047, and 0.016 \u00b1 0.009. An additional compositional variation is evident in both the \u00b3He and electron signatures. These variations are particularly interesting as the three larger events are likely a result of similar eruptions from the same active region.", "doi": "10.1051/0004-6361/202039299", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-06", "volume": "650", "pages": "Art. No. A23" }, { "id": "authors:fhxw7-c2s45", "collection": "authors", "collection_id": "fhxw7-c2s45", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210608-101914332", "type": "article", "title": "Thin silicon solid-state detectors for energetic particle measurements. Development, characterization, and application on NASA's Parker Solar Probe mission", "author": [ { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" }, { "family_name": "Burnham", "given_name": "J. A.", "clpid": "Burnham-J-A" }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Cook", "given_name": "W. R.", "clpid": "Cook-Walter-R" }, { "family_name": "Crabill", "given_name": "R. M.", "clpid": "Crabill-Robert-M" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Kecman", "given_name": "B.", "clpid": "Kecman-Branislav" }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444", "clpid": "Rankin-Jamie-S" }, { "family_name": "Rusert", "given_name": "M. D.", "clpid": "Rusert-M-D" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937" }, { "family_name": "Goodwin", "given_name": "P. A." }, { "family_name": "Link", "given_name": "J. T." }, { "family_name": "Nahory", "given_name": "B. W." }, { "family_name": "Shuman", "given_name": "S. A." }, { "family_name": "von Rosenvinge", "given_name": "T. T." }, { "family_name": "Tindall", "given_name": "C. S." }, { "family_name": "Black", "given_name": "H." }, { "family_name": "Bullough", "given_name": "M." }, { "family_name": "Clarke", "given_name": "N." }, { "family_name": "Glasson", "given_name": "V." }, { "family_name": "Greenwood", "given_name": "N." }, { "family_name": "Hawkins", "given_name": "C." }, { "family_name": "Johnson", "given_name": "T. L." }, { "family_name": "Newton", "given_name": "A." }, { "family_name": "Richardson", "given_name": "K." }, { "family_name": "Walsh", "given_name": "S." }, { "family_name": "Wilburn", "given_name": "C." }, { "family_name": "Birdwell", "given_name": "B." }, { "family_name": "Everett", "given_name": "D. T." }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158" }, { "family_name": "Weidner", "given_name": "S. E." }, { "family_name": "Angold", "given_name": "N. G." }, { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283" } ], "abstract": "Context. Silicon solid-state detectors are commonly used for measuring the specific ionization, dE\u2215dx, in instruments designed for identifying energetic nuclei using the dE\u2215dx versus total energy technique in space and in the laboratory. The energy threshold and species resolution of the technique strongly depend on the thickness and thickness uniformity of these detectors.\nAims. Research has been carried out to develop processes for fabricating detectors that are thinner than 15 \u03bcm, that have a thickness uniformity better than 0.2 \u03bcm over cm\u00b2 areas, and that are rugged enough to survive the acoustic and vibration environments of a spacecraft launch.\nMethods. Silicon-on-insulator wafers that have a device layer of the desired detector thickness supported by a thick handle layer were used as starting material. Standard processing techniques were used to fabricate detectors on the device layer, and the underlying handle-layer material was etched away leaving a thin, uniform detector surrounded by a thick, supporting frame.\nResults. Detectors as thin as 12 \u03bcm were fabricated in two laboratories and successfully subjected to environmental and performance tests. Two detector designs were used in the High-energy Energetic Particles Instrument, which is part of the Integrated Science Investigation of the Sun instrument suite on NASA's Parker Solar Probe spacecraft. These detectors have been performing well for more than two years in space.\nConclusions. Thin silicon detectors in d E\u2215dx versus total energy instruments enable the identification of nuclei with energies down to ~1 MeV nuc\u207b\u00b9. This research suggests that detectors at least a factor of two thinner should be achievable using this fabrication technique.", "doi": "10.1051/0004-6361/202039754", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-06", "volume": "650", "pages": "Art. No. A27" }, { "id": "authors:vr5gp-mw017", "collection": "authors", "collection_id": "vr5gp-mw017", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210608-095304738", "type": "article", "title": "Time evolution of stream interaction region energetic particle spectra in the inner heliosphere", "author": [ { "family_name": "Joyce", "given_name": "C. J.", "orcid": "0000-0002-3841-5020", "clpid": "Joyce-Colin-J" }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158", "clpid": "McComas-David-J" }, { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283", "clpid": "Schwadron-Nathan-A" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937", "clpid": "Christian-Eric-R" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" }, { "family_name": "McNutt", "given_name": "R. L.", "orcid": "0000-0002-4722-9166", "clpid": "McNutt-Ralph-L-Jr" }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Mitchell", "given_name": "D. G.", "orcid": "0000-0003-1960-2119", "clpid": "Mitchell-Donald-G" }, { "family_name": "Hill", "given_name": "M. E.", "orcid": "0000-0002-5674-4936", "clpid": "Hill-Matthew-E" }, { "family_name": "Roelof", "given_name": "E. C.", "orcid": "0000-0002-2270-0652", "clpid": "Roelof-Edmond-C" }, { "family_name": "Allen", "given_name": "R. C.", "orcid": "0000-0003-2079-5683", "clpid": "Allen-Robert-C" }, { "family_name": "Szalay", "given_name": "J. R.", "orcid": "0000-0003-2685-9801", "clpid": "Szalay-Jamey-R" }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444", "clpid": "Rankin-Jamie-S" }, { "family_name": "Desai", "given_name": "M. I.", "orcid": "0000-0002-7318-6008", "clpid": "Desai-Mihir-I" }, { "family_name": "Giacalone", "given_name": "J.", "orcid": "0000-0002-0850-4233", "clpid": "Giacalone-Joe" }, { "family_name": "Matthaeus", "given_name": "W. H.", "orcid": "0000-0001-7224-6024", "clpid": "Matthaeus-William-H" }, { "family_name": "Bale", "given_name": "S. D.", "orcid": "0000-0002-1989-3596", "clpid": "Bale-Stuart-D" }, { "family_name": "Kasper", "given_name": "J. C.", "orcid": "0000-0002-7077-930X", "clpid": "Kasper-Justin-C" } ], "abstract": "We analyze an energetic proton event associated with a stream interaction region (SIR) that was observed at Parker Solar Probe on day 320 of 2018 when the spacecraft was just 0.34 AU from the Sun. Using the Integrated Science Investigation of the Sun instrument suite, we perform a spectral analysis of the event and show how the observed spectra evolve over the course of the event. We find that the spectra from the first day of the event are much more consistent with local acceleration at a weak compression, while spectra from later on are more typical of SIR-related events in which particles accelerated at distant shocks dominate. After the first day, the spectra remain approximately constant, which indicates that the modulation of energetic particles during transit from the presumed source region is weaker than previously thought. We argue that these observations can be explained by a sub-Parker spiral magnetic field structure connecting the spacecraft to a source region in the SIR that is relatively close to the Sun. We further propose that acceleration at weak, pre-shock compressions likely plays an important role in observations of SIR-related events in the inner heliosphere and that future modelling of such events should consider acceleration all along the compression region, not just at the distant shock region.", "doi": "10.1051/0004-6361/202039330", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-06", "volume": "650", "pages": "Art. No. L5" }, { "id": "authors:nvr6t-qq802", "collection": "authors", "collection_id": "nvr6t-qq802", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210609-073141024", "type": "article", "title": "A new view of energetic particles from stream interaction regions observed by Parker Solar Probe", "author": [ { "family_name": "Schwadron", "given_name": "N. A.", "orcid": "0000-0002-3737-9283", "clpid": "Schwadron-Nathan-A" }, { "family_name": "Joyce", "given_name": "C. J.", "orcid": "0000-0002-3841-5020" }, { "family_name": "Aly", "given_name": "A." }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Desai", "given_name": "M. I.", "orcid": "0000-0002-7318-6008" }, { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158" }, { "family_name": "Niehof", "given_name": "J. T." }, { "family_name": "M\u00f6bius", "given_name": "E." }, { "family_name": "Lee", "given_name": "M." }, { "family_name": "Bower", "given_name": "J." }, { "family_name": "Bale", "given_name": "S.", "orcid": "0000-0002-1989-3596" }, { "family_name": "Case", "given_name": "A.", "orcid": "0000-0002-3520-4041" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937" }, { "family_name": "Davis", "given_name": "A. J.", "clpid": "Davis-Andrew-J" }, { "family_name": "de Wet", "given_name": "W." }, { "family_name": "Goetz", "given_name": "K.", "orcid": "0000-0003-0420-3633" }, { "family_name": "Giacalone", "given_name": "J.", "orcid": "0000-0002-0850-4233" }, { "family_name": "Hill", "given_name": "M. E.", "orcid": "0000-0002-5674-4936" }, { "family_name": "Allen", "given_name": "R.", "orcid": "0000-0003-2079-5683" }, { "family_name": "Kasper", "given_name": "J. C.", "orcid": "0000-0002-7077-930X" }, { "family_name": "Korreck", "given_name": "K.", "orcid": "0000-0001-6095-2490" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Malandraki", "given_name": "O.", "orcid": "0000-0002-4751-6835" }, { "family_name": "Matthaeus", "given_name": "W. H.", "orcid": "0000-0001-7224-6024" }, { "family_name": "McNutt", "given_name": "R. L.", "orcid": "0000-0002-4722-9166" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Mitchell", "given_name": "D. G.", "orcid": "0000-0003-1960-2119" }, { "family_name": "Pulupa", "given_name": "M.", "orcid": "0000-0002-1573-7457" }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444" }, { "family_name": "Roelof", "given_name": "E. C.", "orcid": "0000-0002-2270-0652" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Szalay", "given_name": "J. R.", "orcid": "0000-0003-2685-9801" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" } ], "abstract": "Early observations from the first orbit of Parker Solar Probe (PSP) show recurrent stream interaction regions that form close to the Sun. Energetic particle enhancements were observed on the 320th\u2013326th day of the year 2018, which corresponds to ~1\u20137 days after the passage of the stream interface between faster and slower solar wind. Energetic particles stream into the inner heliosphere to the PSP spacecraft near 0.33 au (71 solar radii) where they are measured by the Integrated Science Investigation of the Sun (IS\u2299IS). The large 6-day time interval over which energetic particles are observed after the stream passage provides a unique perspective on the development of stream interactions within the heliosphere. The long duration of energetic particle enhancements suggests that particles stream in through the inner heliosphere more directly along magnetic field lines that form a sub-Parker spiral structure due to magnetic footpoint motion at the Sun and shearing of the magnetic field in the rarefaction region behind the stream interface. The strong build-up of energetic particle fluxes in the first 3 days after the passage of the stream interface indicates that suprathermal populations are enhanced near the interaction region through compression or other acceleration processes in addition to being diffusively accelerated. The early increases in energetic particle fluxes (in the first 3 days) in the formation of these events allows for the characterization of the acceleration associated with these suprathermal seed populations. Thus, we show that the time history of energetic particle fluxes observed by IS\u2299IS provides a new view of particle acceleration at stream interaction regions throughout the inner heliosphere.", "doi": "10.1051/0004-6361/202039352", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-06", "volume": "650", "pages": "Art. No. A24" }, { "id": "authors:6q2n8-khk11", "collection": "authors", "collection_id": "6q2n8-khk11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210205-093236142", "type": "article", "title": "Timing Calibration of the NuSTAR X-Ray Telescope", "author": [ { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Markwardt", "given_name": "Craig B.", "orcid": "0000-0001-9803-3879", "clpid": "Markwardt-Craig-B" }, { "family_name": "Grefenstette", "given_name": "Brian W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Gotthelf", "given_name": "Eric V.", "orcid": "0000-0003-3847-3957", "clpid": "Gotthelf-Eric-V" }, { "family_name": "Kuiper", "given_name": "Lucien", "orcid": "0000-0002-7889-6586", "clpid": "Kuiper-Lucien" }, { "family_name": "Barret", "given_name": "Didier", "orcid": "0000-0002-0393-9190", "clpid": "Barret-Didier" }, { "family_name": "Cook", "given_name": "W. Rick", "clpid": "Cook-W-Rick" }, { "family_name": "Davis", "given_name": "Andrew", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "F\u00fcrst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-Felix" }, { "family_name": "Forster", "given_name": "Karl", "orcid": "0000-0001-5800-5531", "clpid": "Forster-Karl" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" }, { "family_name": "Miyasaka", "given_name": "Hiromasa", "orcid": "0000-0002-8074-4186", "clpid": "Miyasaka-Hiromasa" }, { "family_name": "Roberts", "given_name": "Bryce", "clpid": "Roberts-Bryce" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" } ], "abstract": "The Nuclear Spectroscopic Telescope Array (NuSTAR) mission is the first focusing X-ray telescope in the hard X-ray (3\u201379 keV) band. Among the phenomena that can be studied in this energy band, some require high time resolution and stability: rotation-powered and accreting millisecond pulsars, fast variability from black holes and neutron stars, X-ray bursts, and more. Moreover, a good alignment of the timestamps of X-ray photons to UTC is key for multi-instrument studies of fast astrophysical processes. In this paper, we describe the timing calibration of the NuSTAR mission. In particular, we present a method to correct the temperature-dependent frequency response of the on-board temperature-compensated crystal oscillator. Together with measurements of the spacecraft clock offsets obtained during downlinks passes, this allows a precise characterization of the behavior of the oscillator. The calibrated NuSTAR event timestamps for a typical observation are shown to be accurate to a precision of ~65 \u03bcs.", "doi": "10.3847/1538-4357/abd1d6", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-02-20", "series_number": "2", "volume": "908", "issue": "2", "pages": "Art. No. 184" }, { "id": "authors:0c97f-h2t19", "collection": "authors", "collection_id": "0c97f-h2t19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190827-123135234", "type": "article", "title": "Probing the energetic particle environment near the Sun", "author": [ { "family_name": "McComas", "given_name": "D. J.", "orcid": "0000-0001-6160-1158", "clpid": "McComas-David-J" }, { "family_name": "Cohen", "given_name": "C. M. S.", "orcid": "0000-0002-0978-8127", "clpid": "Cohen-Christina-M-S" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" } ], "abstract": "NASA's Parker Solar Probe mission recently plunged through the inner heliosphere of the Sun to its perihelia, about 24 million kilometres from the Sun. Previous studies farther from the Sun (performed mostly at a distance of 1 astronomical unit) indicate that solar energetic particles are accelerated from a few kiloelectronvolts up to near-relativistic energies via at least two processes: 'impulsive' events, which are usually associated with magnetic reconnection in solar flares and are typically enriched in electrons, helium-3 and heavier ions, and 'gradual' events, which are typically associated with large coronal-mass-ejection-driven shocks and compressions moving through the corona and inner solar wind and are the dominant source of protons with energies between 1 and 10 megaelectronvolts. However, some events show aspects of both processes and the electron\u2013proton ratio is not bimodally distributed, as would be expected if there were only two possible processes. These processes have been very difficult to resolve from prior observations, owing to the various transport effects that affect the energetic particle population en route to more distant spacecraft. Here we report observations of the near-Sun energetic particle radiation environment over the first two orbits of the probe. We find a variety of energetic particle events accelerated both locally and remotely including by corotating interaction regions, impulsive events driven by acceleration near the Sun, and an event related to a coronal mass ejection. We provide direct observations of the energetic particle radiation environment in the region just above the corona of the Sun and directly explore the physics of particle acceleration and transport.", "doi": "10.1038/s41586-019-1811-1", "pmcid": "PMC6908744", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2019-12-12", "series_number": "7786", "volume": "576", "issue": "7786", "pages": "223-227" }, { "id": "authors:kgz8v-28k74", "collection": "authors", "collection_id": "kgz8v-28k74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160722-094105351", "type": "article", "title": "Observations of the Li, Be, and B isotopes and constraints on cosmic-ray propagation", "author": [ { "family_name": "de Nolfo", "given_name": "G. A.", "orcid": "0000-0002-3677-074X", "clpid": "de-Nolfo-Georgia-A" }, { "family_name": "Moskalenko", "given_name": "I. V.", "orcid": "0000-0003-2272-2103", "clpid": "Moskalenko-Ivan-V" }, { "family_name": "Binns", "given_name": "W. R.", "orcid": "0000-0001-6110-3407", "clpid": "Binns-Walter-R" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937", "clpid": "Christian-Eric-R" }, { "family_name": "Cummings", "given_name": "A. C.", "orcid": "0000-0002-3840-7696", "clpid": "Cummings-Alan-C" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "George", "given_name": "J. S.", "clpid": "George-J-S" }, { "family_name": "Hink", "given_name": "P. L.", "orcid": "0000-0002-0904-7564", "clpid": "Hink-Paul-L" }, { "family_name": "Israel", "given_name": "M. H.", "orcid": "0000-0002-8104-208X", "clpid": "Israel-Martin-H" }, { "family_name": "Leske", "given_name": "R. A.", "orcid": "0000-0002-0156-2414", "clpid": "Leske-Richard-A" }, { "family_name": "Lijowski", "given_name": "M.", "clpid": "Lijowski-M-L" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Strong", "given_name": "A. W.", "orcid": "0000-0003-3799-5489", "clpid": "Strong-Andrew-W" }, { "family_name": "von Rosenvinge", "given_name": "T. T.", "orcid": "0000-0001-7320-4141", "clpid": "von-Rosenvinge-Tycho-T" }, { "family_name": "Wiedenbeck", "given_name": "M. E.", "orcid": "0000-0002-2825-3128", "clpid": "Wiedenbeck-Mark-E" }, { "family_name": "Yanasak", "given_name": "N. E.", "clpid": "Yanasak-N-E" } ], "abstract": "The abundance of Li, Be, and B isotopes in galactic cosmic rays (GCRs) between E = 50 and 200 MeV/nucleon has been observed by the Cosmic Ray Isotope Spectrometer (CRIS) on NASA's ACE mission since 1997 with high statistical accuracy. Precise observations of Li, Be, and B can be used to constrain GCR propagation models. We find that a diffusive reacceleration model with parameters that best match CRIS results (e.g., B/C, Li/C, etc.) are also consistent with other GCR observations. A \u02dc15-20% overproduction of Li and Be in the model predictions is attributed to uncertainties in the production cross-section data. The latter becomes a significant limitation to the study of rare GCR species that are generated predominantly via spallation.", "doi": "10.1016/j.asr.2006.09.008", "issn": "0273-1177", "publisher": "Elsevier", "publication": "Advances in Space Research", "publication_date": "2006", "series_number": "7", "volume": "38", "issue": "7", "pages": "1558-1564" }, { "id": "authors:wns4n-q8s48", "collection": "authors", "collection_id": "wns4n-q8s48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140617-164044646", "type": "book_section", "title": "The Cosmic Ray \u00b3He/\u2074He Ratio from 0.2 to 3.6 GeV/nucleon", "author": [ { "family_name": "Reimer", "given_name": "O.", "clpid": "Reimer-O" }, { "family_name": "Barbier", "given_name": "L. M.", "clpid": "Barbier-L-M" }, { "family_name": "Christian", "given_name": "E. R.", "orcid": "0000-0003-2134-3937", "clpid": "Christian-Eric-R" }, { "family_name": "Davis", "given_name": "A. J.", "orcid": "0000-0002-9922-8915", "clpid": "Davis-Andrew-J" }, { "family_name": "Golden", "given_name": "R. L.", "clpid": "Golden-R-L" }, { "family_name": "Hof", "given_name": "M.", "orcid": "0000-0003-2884-3037", "clpid": "Hof-Martin" }, { "family_name": "Krombel", "given_name": "K. E.", "clpid": "Krombel-K-E" }, { "family_name": "Labrador", "given_name": "A. W.", "orcid": "0000-0001-9178-5349", "clpid": "Labrador-Allan-W" }, { "family_name": "Menn", "given_name": "W.", "clpid": "Menn-W" }, { "family_name": "Mewaldt", "given_name": "R. A.", "orcid": "0000-0003-2178-9111", "clpid": "Mewaldt-R-A" }, { "family_name": "Mitchell", "given_name": "J. W.", "clpid": "Mitchell-J-W" }, { "family_name": "Ormes", "given_name": "J. F.", "clpid": "Ormes-J-F" }, { "family_name": "Rasmussen", "given_name": "I. L.", "clpid": "Rasmussen-I-L" }, { "family_name": "Schindler", "given_name": "S. M.", "clpid": "Schindler-Stephen-M" }, { "family_name": "Simon", "given_name": "M. I.", "clpid": "Simon-M-I-Astro" }, { "family_name": "Stochaj", "given_name": "S. J.", "clpid": "Stochaj-S-J" }, { "family_name": "Stone", "given_name": "E. C.", "orcid": "0000-0002-2010-5462", "clpid": "Stone-E-C" }, { "family_name": "Streitmatter", "given_name": "R. E.", "clpid": "Streitmatter-R-E" }, { "family_name": "Webber", "given_name": "W. R.", "orcid": "0000-0001-9238-9145", "clpid": "Webber-William-R" } ], "contributor": [ { "family_name": "Iucci", "given_name": "M.", "clpid": "Iucci-M" }, { "family_name": "Lamanna", "given_name": "E.", "clpid": "Lamanna-E" } ], "abstract": "The abundances of cosmic ray helium isotopes between 0.2 and 3.6 GeV/n were measured by the IMAX balloon-borne magnet spectrometer during a flight in Canada in July, 1992. A high-resolution time-of-flight system and two silica-aerogel Cherenkov counters were used in conjunction with a drift chamber/MWPC-tracking system to determine mass by means of the velocity vs. magnetic rigidity technique.", "publisher": "Caltech Library", "publication_date": "1995-09" } ]