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Survey of van allen belt radiations, galactic cosmic radiation, and solar cosmic radiation provides an estimate of the upper and lower limits of radiation doses under different amounts of mass shielding
Data on the cosmic microwave background radiation obtained with a maser at 12 mm and a Schottky diode mixer at 3 mm are presented. The dipole anisotropy, apparently due to our motion, has been measured sufficiently well to determine our direction of motion within two degrees. The results show that the Galaxy is moving in a direction that is about 44 deg from the center of the Virgo cluster.
Hazard of solar and galactic cosmic radiation
This presentation will be presented at FY 2020 SDRD Annual (Webex) Meeting scheduled for September 23–24, 2020. Evaluating Use of the NASA Nowcastof Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) System for Verifying/Validating AMS Cosmic Background Radiation Measurements, RSLA-006-20, Year 1
Superconducting cosmic strings can be significant energy sources, keeping the universe ionized past the commonly assumed epoch of recombination. As a result, the spectrum of the cosmic background radiation is distorted in the presence of heated primordial gas via the Suniaev-Zel'dovich effect. Thiis distortion can be relatively large: the Compton y parameter attains a maximum in the range 0.001-0.005, with these values depending on the mass scale of the string. A significant contribution to y comes from loops decaying at high redshift when the universe is optically thick to Thomson scattering. Moreover, the isotropic spectral distortion is large compared to fluctuations at all angular scales.
The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere inducing a cascade of particles that eventually impact the earth's surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usoskin et al. formally define solar modulation potential as 'the mean energy loss [per unit charge, in units of megavolts (MV),] of a cosmic ray particle inside the heliosphere...'. Modulation potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector background thresholds require adjustment to account for differing background levels, caused in part by differing solar modulations. Failure to do this can result in higher rates of false positives and failed detection of SNM during low and high levels of solar modulation potential, respectively. This study focuses on solar modulation's time dependence and seeks the best method to predict modulation for future dates. The best method will be incorporated into NINESIM, a discrete event simulator. An in-depth description of NINESIM is beyond the scope and purpose of this paper. (authors)
The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulation potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.
Correlation of plasma velocity with indices of solar and terrestrial activity - cosmic radiation
Damping of interstellar plasma waves by cosmic radiation fluxes due to suprathermal particles - Magnetosonic and Alfven waves
Cosmic gamma radiation searched with vidicon spark chamber flown in high-altitude balloon
Cosmic gamma radiation detection with vidicon spark chamber on high altitude balloon
Cosmic microwave radiation from observations of interstellar CN rotational temperature, rotational exitation by H I region H atoms and excitation by slow electrons and slow protons in H II region
Diffuse omnidirectional inverse Compton and synchrotron X and gamma radiation from cosmic distributions of fast electrons and thermal photons
In order to evaluate the effects of weightlessness and cosmic radiations on the bacteria resistance to antibiotics, the Antibio 23F experiment was undertaken onboard Discovery during the 1st International Microgravity Laboratory (IML-1) mission. The effects of various antibiotic concentrations (dihydrostreptomycin) on Escherichia coli growth and cell division behavior were studied. The antibiotic binding was investigated using a radioactive tracer (tritium). The results showed that microgravity did not affect E. coli cells in regards the growth and the cell division. The antibiotic added to the culture medium induced an inhibition of the cultures both in the flight and ground controls. However, the antibiotic was less efficient in flight. The behavior of bacteria was modified, and the exponential growth rate was increased in flight. The incorporation of radioactive antibiotics in flight was comparatively different to ground incorporation, which indicated some perturbations in antibiotic binding. The experiments performed in the 1 g centrifuge did not show any difference in the cultures developed on the static rack, and could support a radiative effect of cosmic radiation to explain the results.
Anisotropy has been detected in the cosmic blackbody radiation with a 33-GHz (0.9 cm) twin-antenna Dicke radiometer flown to an altitude of 20 km aboard a U-2 aircraft. In data distributed over two-thirds of the Northern Hemisphere, an anisotropy is observed, which is well fitted by a first-order spherical harmonic with an amplitude of (3.5 plus or minus 0.6) x 10 to the -3rd deg K, and direction 11.0 plus or minus 0.6 h right ascension and 6 plus or minus 10 deg declination. This observation is readily interpreted as due to motion of the earth relative to the radiation with a velocity of 390 plus or minus 60 km/sec.
The radiation danger of space flights is due primarily to intensive proton fluxes accompanying solar flares and heavy multiple charged ions in galactic cosmic radiation. Evaluation of the biological effect of these kinds of rays is based on calculations of tissue dose, taking into account the formation of secondary radiation in shielding and tissue. The essential role in such calculations is played by the dependence of the factor of quality on linear energy transfer (LET) of these charged particles. Recommendations concerning the dependence of the quality factor on LET are based on radiobiological experiments carried out on many biological systems using various kinds of rays, including heavy ions with energies in the 1-10 Mev/nucleon range. Justification of the results of these experiments, as well as their extrapolation to other energies, requires development of a model description of the radiation effect of charged particles on biological microstructures.
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The spectrum of the cosmic background radiation in five frequency bands extending from 2.3 to 11.0 cm with a balloon-borne liquid-helium-cooled photometer. The photometer compares the flux from the sky to the flux from an internal blackbody at 3.2 K. All five measurements are consistent with temperatures in the range 2.78 + or = 0.11 K, which is in good agreement with tempratures measured at lower frequencies. No significant deviation from a thermal spectrum was found.