https://doi.org/10.1140/epjp/s13360-019-00092-1
Regular Article
Measurements of the low-energy neutron and gamma ray accompaniment of extensive air showers in the knee region of primary cosmic ray spectrum
1
P. N. Lebedev Physical Institute of the Russian Academy of Sciences (LPI), 119991, Leninsky av., 53, Moscow, Russia
2
Satbayev University, Institute of Physics and Technology, 050032, Ibragimova Str. 11, Almaty, Kazakhstan
3
Institute of Ionosphere, 050020, Kamenskoye plateau, Almaty, Kazakhstan
4
Institute of Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 050040, Al-Farabi av., 71, Almaty, Kazakhstan
* e-mail: ashep@tien-shan.org
Received:
29
June
2019
Accepted:
28
December
2019
Published online:
23
January
2020
Purposeful investigation of radiation fluxes strongly delayed in relation to the main particle front of extensive air shower (EAS) was undertaken at the Tien Shan Mountain Cosmic Ray Station. It was found that the passage of the EAS can be accompanied by the delayed thermal neutrons and by the soft (30–50) keV gamma rays, mostly concentrated within a region of about (5–10) m around the shower axis, where the integral radiation fluence can vary in the limits of 
cm
for neutrons, and of 
cm for gamma rays. The dependence of signal multiplicity on the shower size 
has a power shape both for the neutron and gamma ray components, with a sharp increase of its power index around the value of 
, which corresponds to the position of the 
eV knee in the primary cosmic ray spectrum. The total duration of detectable radiation signal after the EAS passage can be of some tens of milliseconds in the case of neutron component, and up to a few whole seconds for gamma rays. The delayed accompaniment of low-energy radiation particles can be an effective probe to study the interaction of the hadronic component of EAS.
© Società Italiana di Fisica (SIF) and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
