The Nature of the Primary Cosmic Radiation and the Origin of the Mesotron

The contribution by Domenico Pacini to the Cosmic Ray Physics

“…Millikan attacked strongly Compton, but after repeating his experiment in 1933 he admitted that there was a latitude effect and that the Cosmic Rays must be (mostly) charged particles. However, it would take until 1941 before it was established in an experiment by Schein [48] that Cosmic Rays was mostly protons.…”

Первичная Компонента Космического Излучения

“…Однако вопрос об основ-ном составе первичного потока оставался нерешённым ещё в про-должение примерно 15 лет. В 1941 г. был произведён опыт, целью которого было измерение высотного хода электронных ливней в свинце 36 . Оказалось, что на большой высоте (давление ~ 3 см рт.…”

SECTION OF PHYSICS AND CHEMISTRY: THE HEAVY NUCLEI OF PRIMARY COSMIC RADIATION*

“…L a t e r t h i s concept became s u s p e c t (T. H. Johnson, 1938), and it w a s shown that t h e charged particles a r e protons rather than electrons (M. Schein et al, 1941). T e n y e a r s ago i t w a s discovered that, i n addition t o protons, t h e primary cosmic radiation also c o n s i s t s of heavier nuclei, from t h o s e of helium up to nuclei more m a s s i v e than t h o s e of iron (P. F r e i e r et al, 1948a).…”