Astrophysics of ultrahigh energy and ecology was the areas of his research.
Two years he was in the Cosmic Ray station on the Musala Peak (1964 – 1966).
J. Stamenov worked in Russia (1972 – 1975).
In the INRNE - BAS he was research fellow (1976 – 1978), associate professor (1980), and professor (1987).
He headed research group (1982 – 1986) and Laboratory on "Astrophysics of ultrahigh energies" in the INRNE - BAS from 1987.
He was deputy director (1989 – 1993) and director of the Institute for Nuclear Research and Nuclear Energy at the Bulgarian Academy of Sciences (1993 – 2010).
J. Stamenov was elected a corresponding member of BAS (2004).
Obituary from the INRNE - BAS