Cosmic-Ray Hydrogen and Helium Nuclei during a Solar Quiet Time in July 1961

1964 ◽  
Vol 133 (3B) ◽  
pp. B818-B827 ◽  
Author(s):  
C. E. Fichtel ◽  
D. E. Guss ◽  
G. R. Stevenson ◽  
C. J. Waddington
Keyword(s):  
Cosmic Ray ◽  
Quiet Time

Energy spectra of carbon and oxygen - Predictions from HELIOS E6 for Solar Orbiter HET

2020 ◽  
Author(s):  
Johannes Marquardt ◽  
Bernd Heber ◽  
Robert Elftmann ◽  
Robert Wimmer-Schweingruber
Keyword(s):  
Energetic Particle ◽  
Solar Minimum ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Spectra ◽  
Particle Detector ◽  
Quiet Time ◽  
Transport Models ◽  
Galactic Cosmic Ray ◽  
Insight Into

<p>Anomalous cosmic rays (ACRs) are well-suited to probe the transport conditions of energetic particles in the innermost heliosphere. We revisit the HELIOS Experiment 6 (E6) data in view of the upcoming Solar Orbiter Energetic Particle Detector (EPD) suite that will perform measurements during a comparable solar minimum within the same distance.</p><p>Adapting the HELIOS energy ranges for oxygen and carbon to the ones given by the High Energy Telescope (HET) allows us to determine predictions for the upcoming measurements but also to put constraints on particle transport models that provide new insight into the boundary conditions close to the Sun.</p><p>We present here the adapted energy spectra of galactic cosmic ray (GCR) carbon and oxygen, as well as of ACR oxygen during solar quiet time periods between 1975 to 1977. Due to the higher energy threshold of HET in comparison to E6 gradients of about 20% at 15 MeV/nucleon are expected. The largest ACR gradient measured by E6 was obtained to be about 75% between 9 and 13 MeV/nucleon and 0.4 AU and 1 AU.</p>

scholarly journals Energy spectra of carbon and oxygen with HELIOS E6

2018 ◽  
Vol 610 ◽  
pp. A42 ◽  
Author(s):  
J. Marquardt ◽  
B. Heber ◽  
M. S. Potgieter ◽  
R. D. Strauss
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Quiet Time ◽  
Transport Models ◽  
Radial Gradient ◽  
The One ◽  
Galactic Cosmic Ray ◽  
Good Agreement ◽  
Inner Heliosphere

Context. Anomalous cosmic rays (ACRs) are well-suited to probe the transport conditions of cosmic rays in the inner heliosphere. We revisit the HELIOS data not only in view of the upcoming Solar Orbiter experiment but also to put constraints on particle transport models in order to provide new insight into the boundary conditions close to the Sun. Aims. We present here the energy spectra of galactic cosmic ray (GCR) carbon and oxygen, as well as of ACR oxygen during solar quiet time periods between 1975 to 1977, utilizing both HELIOS spacecraft at distances between ~0.3 and 1 AU. The radial gradient (Gr ≈ 50%/AU) of 9–28.5 MeV ACR oxygen in the inner heliosphere is about three times larger than the one determined between 1 and 10 AU by utilizing the Pioneer 10 measurements. Methods. The chemical composition as well as the energy spectra have been derived by applying the dE∕dx − E-method. In order to derive these values, special characteristics of the instrument have been taken into account. Results. A good agreement of the GCR energy spectra of carbon and oxygen measured by the HELIOS E6 instrument between 0.3 and 1 AU and the Interplanetary Monitoring Platform (IMP) 8 at 1 AU was found. For ACR oxygen, we determined a radial gradient of about 50%/AU that is three times larger than the one between 7 and 14 AU, indicating a strong change in the inner heliosphere.

Quiet time interplanetary cosmic ray anisotropies observed from Pioneer 10 and 11

1978 ◽  
Vol 83 (A4) ◽  
pp. 1633 ◽  
Author(s):  
W. -H. Ip ◽  
W. Fillius ◽  
A. Mogro-Campero ◽  
L. J. Gleeson ◽  
W. I. Axford
Keyword(s):  
Cosmic Ray ◽  
Quiet Time ◽  
Pioneer 10

Direct measurements of geomagnetic cutoffs for cosmic-ray particles in the latitude range 45° to 70° using balloons and satellites

1968 ◽  
Vol 46 (10) ◽  
pp. S1078-S1081 ◽  
Author(s):  
R. G. Bingham ◽  
D. M. Sawyer ◽  
J. F. Ormes ◽  
W. R. Webber
Keyword(s):  
Ring Current ◽  
Cosmic Ray ◽  
Internal Field ◽  
Diurnal Changes ◽  
Quiet Time ◽  
Latitude Range ◽  
Surface Field ◽  
The Earth ◽  
Direct Measurements ◽  
Polar Orbiting Satellite

The quiet-time cutoff rigidities for cosmic-ray particles have been measured directly in 1963–65 at six locations in North America with geomagnetic latitudes (λ) between 45° and 70° using balloon-borne Cerenkov-scintillation counters. An identical counter with 0.1 of the area has been carried aloft in a polar-orbiting satellite from which it has been possible to determine the cutoffs for protons in four intervals between L = 3 and L = 5. The measured cutoffs are consistently below those expected on the basis of detailed orbit calculations based on the surface field of the earth (Shea and Smart 1967). These differences amount to a [Formula: see text] reduction at λ = 45°, increasing to [Formula: see text] at 60°. At 70° the cutoff is apparently <12% of the expected internal field value at 190 MV at 2100 hours local time.A limit to the amount of reduction produced by a ring current within the magnetosphere can be set from the data at latitudes <60°. The most reasonable value for the magnetic moment of this ring current is 0.08 Me. The situation at latitudes >60° is characterized by large diurnal changes in the cutoffs.

scholarly journals Cosmic ray cutoff prediction using magnetic field from global magnetosphere MHD simulations

2005 ◽  
Vol 23 (4) ◽  
pp. 1441-1453 ◽  
Author(s):  
J. M. Weygand ◽  
J. Raeder
Keyword(s):  
Geomagnetic Field ◽  
Cosmic Ray ◽  
Alpha Particles ◽  
Maximum Difference ◽  
Quiet Time ◽  
Earth’S Magnetosphere ◽  
Cutoff Energy ◽  
Earth's Magnetosphere ◽  
Geomagnetic Field Models ◽  
Mhd Model

Abstract. Relativistic particles entering the Earth's magnetosphere, i.e. cosmic rays and solar energetic particles, are of prime space weather interest because they can affect satellite operations, communications, and the safety of astronauts and airline crews and passengers. In order to mitigate the hazards that originate from such particles one needs to predict the cutoff latitudes of such particles as a function of their energies and the state of the magnetosphere. We present results from a new particle tracing code that is used to determine the cutoff latitudes of 8-15Men-1 alpha particles during the 23/24 April, 1998 geomagnetic storm and the preceding quiet time. The calculations are based on four different geomagnetic field models and compared with SAMPEX observations of alpha particles in the same energy range. The geomagnetic field models under consideration are: (i) the International Geomagnetic Reference Field (IGRF) model, (ii) the Tsyganenko "89" model (T89c), (iii) the Tsyganenko "96" model (T96), and (iv) a global magnetohydrodynamic (MHD) model of Earth's magnetosphere. Examining 11 SAMPEX cutoff latitude observations we find that the differences between the observed and the predicted cutoff latitudes are 2.3° ± 2.0° (mean) and 7.9° (maximum difference) for the IGRF model; 3.9° ± 2.4° (mean) and 6.9° (maximum difference) for the T89c model; 4.0° ± 1.4° (mean) and 5.5° (maximum difference) for the T96 model; and 2.5° ± 1.7° (mean) and 7.0° (maximum difference) for the MHD model. All models generally predict cutoff latitudes equatorward of the SAMPEX observations. The MHD model results also show steeper cutoff energy gradients with latitude compared to the empirical models and more structure in the cutoff energy versus latitude function, presumably due to the presence of boundary layers in the MHD model.

scholarly journals Variability of quiet-time diurnal amplitude and phase of cosmic ray count rates in the mid- and high latitudes

2017 ◽  
Vol 12 (22) ◽  
pp. 295-307
Author(s):  
Ugochukwu Okiyi ◽  
Kingsley C. Okpala ◽  
James O. Tsor ◽  
Friday Egbunu
Keyword(s):  
Cosmic Ray ◽  
High Latitudes ◽  
Quiet Time ◽  
Diurnal Amplitude

DEVELOPMENT OF THE COSMIC RAY TECHNIQUES

1982 ◽  
Vol 43 (C8) ◽  
pp. C8-69-C8-88 ◽  
Author(s):  
B. Rossi
Keyword(s):  
Cosmic Ray
Sign in / Sign up

Export Citation Format

Share Document