Nicolaas 'Nico' Godfried van Kampen (June 22, 1921 – October 6, 2013) was a Dutch theoretical physicist, who worked mainly on statistical mechanics and non-equilibrium thermodynamics.
He studied physics at Leiden University, where in 1952 under the direction of Hendrik Anthony Kramers he earned his PhD with thesis Contributions to the quantum theory of light scattering.
[2] He showed in his thesis how to deal with singularities in quantum mechanical scattering processes, an important step in the development of renormalization, according to Kramers.
[3] Van Kampen made fundamental contributions to non-equilibrium processes (in particular on the master equation) and in many-body theory (especially in plasma physics).
His work on non-equilibrium processes began in 1953 in the research group of Sybren Ruurds de Groot (the successor to Kramers) in Leiden.