Neutron and 2. 223-MeV gamma-ray line emission from solar flares

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6405684

Hua, X M

Systematic calculations of the neutron and 2.223 MeV gamma-ray line production in solar flares and their escape fluxes as a function of angle, energy, and time were carried out. With a connected system of Monte Carlo programs, the depth, energy and angular dependences of the neutron production and their subsequent capture gamma ray line emission in the solar atmosphere were calculated as a function of the accelerated ion energy spectrum and angular distribution, and then the attenuation of the escaping neutrons and gamma rays were calculated as a function of energy and observing angle, or heliocentric position. The calculation also gave the time dependent gamma ray and neutron flux at the Earth. Comparisons of the results of these calculations with solar flare gamma ray and neutron observations yielded important new information on both the flare-accelerated ions and the solar /sup 3/He abundance. In particular, from a study of the escaping neutrons, it is found that the accelerated ions interacting in the solar atmosphere appear to be highly anisotropic with a mirroring angular distribution, similar to that found for the accelerated electrons. From a study of the time dependence of the 2.223-MeV capture gamma ray line emission, the /sup 3/He/H ratio in the solar photosphere was found to be (2.3 +/- 1.2) x 10/sup -5/.

• Research Organization: California Univ., San Diego (USA)
• OSTI ID: 6405684
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
CHARGED PARTICLES
ELECTROMAGNETIC RADIATION
EMISSION
ENERGY RANGE
EVEN-ODD NUCLEI
GAMMA RADIATION
HELIUM 3
HELIUM ISOTOPES
IONIZING RADIATIONS
IONS
ISOTOPES
LIGHT NUCLEI
MEV RANGE
MEV RANGE 01-10
NEUTRON EMISSION
NUCLEI
PHOTON EMISSION
RADIATIONS
SOLAR ACTIVITY
SOLAR FLARES
STABLE ISOTOPES