A study of atmospheric neutrons by the resonance detector method

The possibilities and the conditions of using resonance detectors for investigation of slow neutrons in the atmosphere are discussed. The epithermal neutron fluxes from the lower hemisphere were measured by means of the indium foil activation method in June 1966 at the geomagnetic latitude 47°. Assuming the epithermal atmospheric neutron spectrum to be Φ(E) = Φ0/E and expressing the neutron energy in eV, we obtain the following values of Φ0 (neutron cm−2 s−1) from our measurements: 0.078 ± 0.019 (at a depth x = 40 g cm−2), 0.049 ± 0.015 (x = 22 g cm−2), 0.023 ± 0.010 (x = 8 g cm−2). It is pointed out that resonance detectors can be used to study the spectra of epithermal neutrons in nonequilibrium atmospheric layers.