Measurements of the low-energy neutron and gamma ray accompaniment of extensive air showers in the knee region of primary cosmic ray spectrum

• Published in: European physical journal plus 2020-01, Vol.135 (1), p.96, Article 96
• Main Authors: Shepetov, Alexander, Chubenko, Alexander, Iskhakov, Bachtiyar, Kryakunova, Olga, Kalikulov, Orazaly, Mamina, Svetlana, Mukashev, Kanat, Piscal, Vyacheslav, Ryabov, Vladimir, Saduyev, Nurzhan, Sadykov, Turlan, Salikhov, Nazyf, Tautaev, Ernar, Vil’danova, Ludmila, Zhukov, Valeriy
• Format: Article
• Language: English
• Subjects: Applied and Technical Physics; Atomic; Complex Systems; Condensed Matter Physics; Cosmic ray showers; Cosmic rays; Energy; Experiments; Fluence; Gamma rays; Knee; Mathematical and Computational Physics; Molecular; Neutrons; Optical and Plasma Physics; Physics; Physics and Astronomy; Primary cosmic rays; Radiation; Registration; Regular Article; Sea level; Sensors; Theoretical; Thermal neutrons
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-019-00092-1

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 ( 10 - 4 - 1 )  cm - 2 for neutrons, and of ( 0.1 - 1000 )  cm - 2 for gamma rays. The dependence of signal multiplicity on the shower size N e has a power shape both for the neutron and gamma ray components, with a sharp increase of its power index around the value of N e ≈ 10 6 , which corresponds to the position of the 3 × 10 15  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.