Cosmic neutron flux and gamma-rays variation as a function of latitude and altitude (in French)
Technical Report
·
OSTI ID:4383352
The measurements of fast neutron spectra from 1 to 15 MeV and of gamma rays from 0.7 to 4.5 MeV were carried out in balloons at 10, 46, and 62 deg N geomagnetic latitudes. The observed spectra followed a law of the form dN/dE = AE/sup - GAMMA / with gamma = 1.4 plus or minus 0.1 for the neutrons and gamma = 1.5 plus or minus 0.1 for the gamma rays. It was observed at the time of the measurements that the exponent ( gamma ) remains constant as a function of the latitude and the altitude between 120 and 4g/cm/sup 2/. The value of the coefficient A is a function of the latitude and of the atmospheric pressure. At 4g/cm/sup 2/ a ratio of 9 exists for the neutrons between the measured fluxes at 10 and 46 deg N while for the gamma rays the ratio is 3. This difference, as well as the analysis of the attenuation length and the position of the Pfotzer maximum for the latitudes, shows that the gamma rays are for the largest part dependent on the photoelectronic component that arises from the decay of pi /sup o/ mesons, produced at the top of the atmosphere by primary cosmic radiation. (tr- auth)
- Research Organization:
- Instituto de Pesquisas Espaciais, Sao Jose dos Campos (Brazil)
- NSA Number:
- NSA-29-005746
- OSTI ID:
- 4383352
- Report Number(s):
- LAFE--140
- Country of Publication:
- Brazil
- Language:
- French
Similar Records
HIGH ALTITUDE NEUTRON INTENSITY DIURNAL VARIATION
Energy spectrum and flux of fast neutrons in the atmosphere
The 0.5-Mev gamma-ray and the low-energy gamma-ray spectrum to 6 grams per square centimeter over Minneapolis
Technical Report
·
Sat Mar 14 23:00:00 EST 1959
·
OSTI ID:4177151
Energy spectrum and flux of fast neutrons in the atmosphere
Journal Article
·
Mon Aug 01 00:00:00 EDT 1977
· Phys. Rev., D; (United States)
·
OSTI ID:7090829
The 0.5-Mev gamma-ray and the low-energy gamma-ray spectrum to 6 grams per square centimeter over Minneapolis
Journal Article
·
Thu Feb 14 23:00:00 EST 1963
· Journal of Geophysical Research
·
OSTI ID:4752737