Differential energy spectra and intensity variation of 1-20 MeV/nucleon protons and helium nuclei in interplanetary space (1964-66)

1968 ◽  
Vol 46 (10) ◽  
pp. S498-S502 ◽  
Author(s):  
C. Y. Fan ◽  
G. Gloeckler ◽  
B. McKibben ◽  
K. R. Pyle ◽  
J. A. Simpson
Keyword(s):  
Solar Activity ◽  
Energy Range ◽  
Interplanetary Space ◽  
Intensity Variation ◽  
Low Energy ◽  
Energy Spectra ◽  
Solar Modulation ◽  
Space Probe ◽  
Solar Origin ◽  
Made In

Measurements made in interplanetary space with a ΔE-range telescope on the OGO I and OGO III satellites and on the Pioneer 7 space probe showed that protons and helium nuclei in the energy range I–20 MeV/nucleon are present during "quiet times" in late 1964, in May–October–November 1965, and in August 1966. The intensities for both proton and helium nuclei are found to decrease with increasing energies. The spectra join those of the particles above 20 MeV/nucleon, which are known to be of galactic origin. For both protons and helium nuclei, the fluxes were higher in the period of minimum solar modulation in 1965 than in 1964. While in 1966 the helium flux decreased to its 1964 level, the proton flux showed a further increase over this period. It is believed that most of the particles observed during the period of minimum solar modulation were of galactic origin. As solar activity increases again, it seems that to the galactic low-energy fluxes, particularly for protons, there is added a steady contribution of solar origin.

Low-energy cosmic-ray heavy nuclei during the time of solar minimum

1968 ◽  
Vol 46 (10) ◽  
pp. S598-S600
Author(s):  
E. Tamai ◽  
M. Tsubomatsu ◽  
K. Ogura
Keyword(s):  
Energy Range ◽  
Solar Minimum ◽  
Cosmic Ray ◽  
Low Energy ◽  
Energy Spectra ◽  
Solar Modulation ◽  
Atmospheric Depth ◽  
Heavy Nuclei ◽  
Multiply Charged ◽  
Α Particles

Nuclear emulsions were exposed at 2.3 g cm−2 atmospheric depth over Fort Churchill in 1965. These emulsions have been examined for the tracks of multiply-charged [Formula: see text] nuclei, with emphasis being paid particularly to those particles that stopped in the emulsions. Differential energy spectra of α particles and [Formula: see text], [Formula: see text]and [Formula: see text] nuclei were obtained in the energy interval 60–550 MeV/nucleon. They represent experimental results during the period when solar modulation effects were at a minimum. The fluxes of α particles and L, M, and H nuclei for energy intervals of 60–170, 100–400, 100–525, and 140–550 MeV/nucleon were found to be 20.9 ± 1.2, 2.4 ± 0.4, 4.8 ± 0.6, and 2.5 ± 0.4 particles m−2 sr−1 s−1, respectively. The results also show that the L/M and H/M ratios at the top of the atmosphere were 0.56 ± 0.16 and 0.34 ± 0.13 respectively, in the energy range from 140 to 350 MeV/nucleon. These values are appreciably greater than those observed at higher energies.

The composition of low-energy cosmic rays in 1965

1968 ◽  
Vol 46 (10) ◽  
pp. S539-S543 ◽  
Author(s):  
D. E. Hagge ◽  
V. K. Balasubrahmanyan ◽  
F. B. McDonald
Keyword(s):  
Cosmic Rays ◽  
Energy Range ◽  
Cosmic Ray ◽  
Low Energy ◽  
Oxygen Flux ◽  
Energy Spectra ◽  
Solar Modulation ◽  
Charge Composition ◽  
Specific Component ◽  
Relative Abundances

Primary cosmic-ray energy spectra and charge composition have been measured during the 1965 period of solar modulation minimum. A dE/dx vs. E type of scintillator–photomultiplier detector on board the eccentric-orbiting NASA spacecraft OGO-I was used. The charge composition was measured through neon over an energy range of 25 to 200 MeV/nucleon, depending upon the specific component. The spectra for all groups are nearly flat during this time, with the oxygen flux at about 0.005 nucleus/(M2-sr-s-MeV/nucleon). The relative abundances found are Li, 0.27; Be, 0.11; B, 0.37; C, 1.20; N, 0.30; O 1.00; F, [Formula: see text]; Ne, 0 12 An L/M ratio of 0.30 ± 0.06 is found.

Satellite measurements of the low-energy cosmic-ray Li, Be, B, C, N, O, F nuclei and their implications

1968 ◽  
Vol 46 (10) ◽  
pp. S548-S552 ◽  
Author(s):  
C. Y. Fan ◽  
George Gloeckler ◽  
J. A. Simpson
Keyword(s):  
Energy Spectrum ◽  
Interplanetary Space ◽  
Cosmic Ray ◽  
Low Energy ◽  
Solar Modulation ◽  
Chemical Abundance ◽  
Satellite Measurements ◽  
Differential Energy Spectrum

The differential energy spectrum and chemical abundance of individual elements from lithium to fluorine have been measured near minimum solar modulation (June 1965 to March 1966) in interplanetary space on the IMP-III satellite. The spectra for Li, Be, and B are found to increase with decreasing energy below ~60 MeV/nucleon. The consequences of these results on the propagation and lifetimes of cosmic-ray particles are discussed.

scholarly journals 43. On the variations of the primary cosmic ray intensity

1958 ◽  
Vol 6 ◽  
pp. 420-427
Author(s):  
E. N. Parker
Keyword(s):  
Solar Activity ◽  
Interplanetary Space ◽  
Particle Density ◽  
Sunspot Cycle ◽  
Forbush Decrease ◽  
Cosmic Ray ◽  
Abrupt Onset ◽  
Cosmic Ray Intensity ◽  
Solar Origin ◽  
Quantitative Development

To construct a model for producing the observed variation in the cosmic ray intensity we consider primarily the Forbush decrease and the general decrease of the cosmic ray intensity during years of solar activity. These are larger variations than the diurnal and 27-day variations and require more drastic assumptions; thus they will better serve to establish a unique model.It is assumed that the sun does not emit cosmic ray particles except during the time of a solar flare. Thus, decreases in the cosmic ray intensity are to be interpreted as a solar effect which inhibits the arrival of galactic cosmic ray particles at earth. Since the intensity of low rigidity primary cosmic ray particles is observed to vary more than the intensity at higher rigidities, the inhibition has generally been assumed to be caused by magnetic fields.The necessary depression of the cosmic ray intensity requires both a barrier, to impede their arrival, and a removal mechanism within the barrier, to prevent eventual statistical equilibrium (with uniform particle density). Quantitative development indicates that a heliocentric magnetic dipole, a heliocentric cavity in the galactic field (Davis, Phys. Rev.100, 1440, 1955), and a heliocentric interplanetary cloud barrier (Morrison, Phys. Rev.101, 1397, 1956) all encounter serious difficulties in explaining the observed effects, one reason being the ineffective removal that is available.It is shown that a geocentric magnetic cloud barrier does not encounter these difficulties: it is proposed that during the years of solar activity the terrestrial gravitational field captures magnetic gas of solar origin from interplanetary space, which is then supported by the geomagnetic field; the removal by absorption by the earth is sufficiently effective that only a relatively thin barrier need be maintained; the occasional capture of new magnetic material accounts for the abrupt onset of the Forbush decreases, and the slow decay (0·5 years) of the captured fields for the smooth variation of the mean cosmic ray intensity with the sunspot cycle.

Two anisotropies of the cosmic-ray particles producing the cosmic-ray diurnal variation

1968 ◽  
Vol 46 (10) ◽  
pp. S828-S830
Author(s):  
Masatoshi Kitamura
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Interplanetary Space ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Diurnal Variations ◽  
Low Energy ◽  
The Other ◽  
Energy Spectra ◽  
Cosmic Ray Intensity

The solar diurnal variations of both meson and nucleon components of cosmic rays at sea level at geomagnetic latitude 57.5° and geomagnetic longitude 0° are analyzed by the model in which two anisotropies of cosmic-ray particles (one of them, Δj1, from about 20 h L.T. and the other, Δj2, from about 8 h L.T. in interplanetary space) produce the solar diurnal variation of the cosmic-ray intensity on the earth.When the energy spectra of Δj1 and Δj2 are represented by [Formula: see text] and [Formula: see text], respectively, where j0(E) is the normal energy spectrum of the primary cosmic rays, it is shown that the evaluation for m1 = 1, 2, m2 = 0 and the cutoffs at 8 and 10 BeV on the low-energy side of spectra of both Δj1 and Δj2 agree well with the observational results at Deep River.

scholarly journals Charmed and bottomed hadronic cross sections from a statistical model

2020 ◽  
Vol 56 (9) ◽  
Author(s):  
Gábor Balassa ◽  
György Wolf
Keyword(s):  
Statistical Model ◽  
Energy Range ◽  
Cross Sections ◽  
Heavy Quarks ◽  
Open Charm ◽  
Low Energy ◽  
Final State ◽  
Proton Antiproton ◽  
Proton Proton

Abstract In this work, we extended our statistical model with charmed and bottomed hadrons, and fit the quark creational probabilities for the heavy quarks, using low energy inclusive charmonium and bottomonium data. With the finalized fit for all the relevant types of quarks (up, down, strange, charm, bottom) at the energy range from a few GeV up to a few tens of GeV’s, the model is now considered complete. Some examples are also given for proton–proton, pion–proton, and proton–antiproton collisions with charmonium, bottomonium, and open charm hadrons in the final state.

A number-conserving calculation of the low-energy spectra of the odd-odd T1 isotopes

1970 ◽  
Vol 68 (3) ◽  
pp. 502-512 ◽  
Author(s):  
A. Fubini ◽  
N. Lo Iudice ◽  
D. Prosperi ◽  
E. Salusti
Keyword(s):  
Low Energy ◽  
Energy Spectra

Investigation of the attenuation of the fluxes of the low-energy plasma component of electric rocket engines by the ventilation holes of the unpressurized instrument compartment of the spacecraft

2021 ◽  
Author(s):  
I.A. Maximov ◽  
A.B. Nadiradze ◽  
R.R. Rakhmatullin ◽  
V.A. Smirnov ◽  
R.E. Tikhomirov ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Plasma Source ◽  
Low Energy ◽  
Rocket Engines ◽  
Plasma Component ◽  
Plasma Flows ◽  
Energy Component ◽  
Honeycomb Filler ◽  
Semi Empirical ◽  
Made In

The results of an experimental study of the attenuation of the fluxes of the low-energy component of the plasma formed during the operation of electric propulsion engines (ERE), ventilation holes (VH) of the non-sealed equipment compartment (NSEC) of the spacecraft (SC) are presented. Authors studied the attenuation of plasma fluxes by standard VHs made in honeycomb panels that form the NSEC. A Hall-effect engine of the SPT-70 type was used as a plasma source. The experiment consisted of measuring the plasma concentration at the inlet and outlet of the VH. The concentration at the inlet was measured with a flat Langmuir probe, and at the outlet with a Faraday probe, which allows collecting all ions passing through the VH. The aim of the work was to study the weakening of the fluxes of the lowenergy component of the EJE plasma when passing through the VH in the honeycomb-nels that form the NSEC. Based on the experimental data, a semi-empirical model was constructed that describes the dependence of the attenuation coefficient of plasma flows on the geometric parameters of the vent-holes. It has been established that a vent-holes of this design attenuates the plasma flows by 102 ... 104 times. The largest contribution to the weakening of plasma fluxes is made by the honeycomb filler, which is due to the recombination of ions during their collision with the channel walls. Taking into account the attenuation of the fluxes of the low-energy component of the plasma of electric rocket engines by ventilation holes is a key stage in assessing the effect of plasma on the power on-board equipment of spacecraft and should be used by spacecraft developers when analyzing the resistance to this factor.

Photoproduction of Gravitational Radiation in Static Electromagnetic Fields. Radiative Corrections

1975 ◽  
Vol 53 (20) ◽  
pp. 2315-2320 ◽  
Author(s):  
G. Papini ◽  
S. -R. Valluri
Keyword(s):  
Cross Section ◽  
Gravitational Radiation ◽  
Low Energy ◽  
Radiative Corrections ◽  
Third Order ◽  
The Third ◽  
Relativistic Approximation ◽  
Effective Lagrangian ◽  
Charge Renormalization ◽  
Made In

The radiative corrections of second and third order for the process of photoproduction of gravitons in Coulomb and magnetic dipole fields have been calculated.All divergences have been removed either by charge renormalization or regularization. No approximations have been made in the calculation of the second order cross section. In the third order calculation only the extreme relativistic approximation is given. The forms of the effective Lagrangian, corresponding to the low energy approximations have been determined.

Sign in / Sign up

Export Citation Format

Share Document