Non-Abelian field strength bilocal correlator at finite temperature in the model of dilute instanton gas

Bilocal correlator in gluodynamics is evaluated at finite temperature in the framework of instanton gas model. It is demonstrated that vacuum correlation length decreases with a growing temperature. Obtained results are compared with lattice data for the bilocal correlator at finite temperature. Density of instantons and possible structures of nonperturbative vacuum are discussed.