COSTEP — Comprehensive Suprathermal and Energetic Particle Analyser

Müller‐Mellin, R.; Kunow, H.; Fleißner, V.; Pehlke, E.; Rode, E.; Röschmann, N.; Scharmberg, C.; Sierks, H.; Rusznyak, P.; McKenna‐Lawlor, S.; Elendt, I.; Sequeiros, J.; Meziat, D.; Sánchez, S. F.; Medina, J.; Peral, L. del; Witte, M.; Marsden, R. G.; Henrion, J.

doi:10.1007/978-94-009-0191-9_13

Cited by 28 publications

(20 citation statements)

References 1 publication

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“…Columns 3 and 4 of Table 3 show the results of inspection of the CoSTEP data (Müller-Mellin et al, 1995) for electrons at energies above 0.25 MeV and protons above 4.3 MeV. The same results are obtained by ACE/EPAM (Gold et al, 1998).…”

Section: A Search For Sep Signatures In Cme-less Flaressupporting

confidence: 57%

Energetic Particle Acceleration and Propagation in Strong CME-Less Flares

2010

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Flares and coronal mass ejections (CMEs) contribute to the acceleration and propagation of solar energetic particles (SEP) detected in the interplanetary space, but the exact roles of these phenomena are yet to be understood. We examine two types of energetic particle tracers related with 15 CME-less flares that emit bright soft X-ray bursts (GOES X class): radio emission of flare-accelerated electrons and in situ measurements of energetic electrons and protons near 1 AU. The CME-less flares are found to be vigorous accelerators of microwave-emitting electrons, which remain confined in low coronal structures. This is shown by unusually steep low-frequency microwave spectra and by lack of radio emission from the middle and high corona, including dm -m wave type IV continua and metre-tohectometre type III bursts. The confinement of the particles accelerated in CME-less flares agrees with the magnetic field configuration of these events inferred by others. Two events produced isolated metric type II bursts revealing coronal shock waves. None of the seven flares in the western hemisphere was followed by enhanced particle fluxes in the GOES detectors, but one, which was accompanied by a type II burst, caused a weak SEP event detected at SoHO and ACE. Three of the CME-less flares were followed within some hours by SEP-associated flares from the same active region. These SEP-producing events were clearly distinct from the CME-less ones by their association with fast and broad CMEs, dm -m wave radio emission, and intense DH type III bursts. We conclude that radio emission at decimetre and longer waves is a reliable indication that flare-accelerated particles have access to the high corona and interplanetary space. The absence of such emission can be used as a signal that no SEP event is to be expected despite the occurrence of a strong soft X-ray burst.

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Section: A Search For Sep Signatures In Cme-less Flaressupporting

confidence: 57%

Energetic Particle Acceleration and Propagation in Strong CME-Less Flares

2010

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“…We therefore use our same methodology for determining the lunar surface potential, but without any correction for the spacecraft potential. In addition, we utilize a combination of LP electron data and high energy electron data from SOHO [ Muller‐Mellin et al , 1995], as described in Halekas et al [2007], to determine the input electron spectrum. We fit the combined electron spectrum to a two‐component distribution and show the resulting density and temperature components in Figure 13.…”

Section: Lunar Surface Potential During a Solar Energetic Particle Eventmentioning

confidence: 99%

Lunar Prospector observations of the electrostatic potential of the lunar surface and its response to incident currents

et al. 2008

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[1] We present an analysis of Lunar Prospector Electron Reflectometer data from selected time periods using newly developed methods to correct for spacecraft potential and self-consistently utilizing the entire measured electron distribution to remotely sense the lunar surface electrostatic potential with respect to the ambient plasma. These new techniques enable the first quantitative measurements of lunar surface potentials from orbit. Knowledge of the spacecraft potential also allows accurate characterization of the downward-going electron fluxes that contribute to lunar surface charging, allowing us to determine how the lunar surface potential reacts to changing ambient plasma conditions. On the lunar night side, in shadow, we observe lunar surface potentials of $À100 V in the terrestrial magnetotail lobes and potentials of $À200 V to $À1 kV in the plasma sheet. In the lunar wake, we find potentials of $À200 V near the edges but smaller potentials in the central wake, where electron temperatures increase and secondary emission may reduce the magnitude of the negative surface potential. During solar energetic particle events, we see nightside lunar surface potentials as large as $À4 kV. On the other hand, on the lunar day side, in sunlight, we generally find potentials smaller than our measurement threshold of $20 V, except in the plasma sheet, where we still observe negative potentials of several hundred volts at times, even in sunlight. The presence of significant negative charging in sunlight at these times, given the measured incident electron currents, implies either photocurrents from lunar regolith in situ two orders of magnitude lower than those measured in the laboratory or nonmonotonic near-surface potential variation with altitude. The functional dependence of the lunar surface potential on electron temperature in shadow implies somewhat smaller secondary emission yields from lunar regolith in situ than previously measured in the laboratory.These new techniques open the door for future studies of the variation of lunar surface charging as a function of temporal and spatial variations in input currents and as a function of location and material characteristics of the surface as well as comparisons to the increasingly sophisticated theoretical predictions now available.

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“…Before we discuss the energetic particle observations by the neutron monitor network we give a brief summary of the history of the interplanetary medium conditions near Earth which controls the time history of the energetic particle profiles. Therefore, Figure 2 displays from top to bottom 5‐min averages of 2.7 to 10 MeV electron, 8 to 25 MeV proton intensities from the Electron Proton Helium Instrument (EPHIN) [ Müller‐Mellin et al , 1995], solar wind density, solar wind temperature, solar wind speed, Helium to Hydrogen ratio from the Solar Wind Electron, Proton, and Alpha Monitor (SWEPAM) [ McComas et al , 1998], magnetic field strength, azimuth and longitude from the Magnetic Field Experiment (MAG) [ Smith et al , 1998] during the period from 13 January to 23 January.…”

Section: Solar Particle Event On 20 January 2005mentioning

confidence: 99%

Temporal and spatial evolution of the solar energetic particle event on 20 January 2005 and resulting radiation doses in aviation

et al. 2009

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[1] The solar energetic particle event on 20 January 2005 was one of the largest ground level events ever observed. Neutron monitor stations in the Antarctic recorded count rate increases of several thousand percent caused by secondary energetic particles, and it took more than 36 h to return to background level. Such huge increases in high energetic solar cosmic radiation on the ground are obviously accompanied by considerable changes in the radiation environment at aviation altitudes. Measurements of 28 neutron monitor stations were used in this work to numerically approximate the primary solar proton spectra during the first 12 h of the event by minimizing the differences between measurements and the results of Monte-Carlo calculated count rate increases. The primary spectrum of solar energetic protons was approximated by a power law in rigidity and a linear angular distribution. The incoming direction of the solar energetic particles was determined and compared to the interplanetary magnetic field direction during the event. The effects on the radiation exposure at altitudes of about 12 km during that time were estimated to range from none at low latitudes up to almost 2 mSv/h for a very short time in the Antarctic region and about 0.1 mSv/h at high latitudes on the Northern Hemisphere. After 12 h, dose rates were still increased by 50% at latitudes above 60°whereas no increases at all occurred at latitudes below 40°during the whole event.

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COSTEP — Comprehensive Suprathermal and Energetic Particle Analyser

Cited by 28 publications

References 1 publication

Energetic Particle Acceleration and Propagation in Strong CME-Less Flares

Energetic Particle Acceleration and Propagation in Strong CME-Less Flares

Lunar Prospector observations of the electrostatic potential of the lunar surface and its response to incident currents

Temporal and spatial evolution of the solar energetic particle event on 20 January 2005 and resulting radiation doses in aviation

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