Measurement of muon production depth in cosmic ray induced extensive air showers by time structure of muons at observation level

• Muon production depth (MPD) of shower is measured from time structure of muons at observation level.
• MPD’ dependence on the Xmax   and XmaxμXmaxμ, and so primary mass of cosmic ray is investigated.
• A new method for calculating MPD is presented.
• Ability of MPD as a mass discriminating parameter between primaries have been investigated.

In the present work, muon production depth (MPD) of extensive air showers (EASs)  are measured from time structure of muons at the observation level. A new method for calculating MPD is presented. Based on its relation to the maximum depth of development of electrons and muons (Xmax   and XmaxμXmaxμ), this parameter has been used as a mass discriminator factor. Using CORSIKA simulation, different simulations for proton and iron primaries in the energy range of 1014–1015 eV are presented. It is found that MPD distribution is strongly related to Xmax   and XmaxμXmaxμ. These are mass sensitive parameters and their potential as mass discriminator parameters between light and heavy primaries for ALBORZ prototype array and some arbitrary arrays are investigated.