The prototype of the polarized deuteron source was made for the Van de Graaff accelerator of the Czech Technical University in Prague with the aim to create a full-scale setup for producing the polarized neutron beam for experiments on measuring ∆σ_L and ∆σ_T, longitudinal and transversal spin asymmetries in the transmission polarized neutron beam through a frozen polarized deuteron target. It is based on Kaminsky’s experiment on channeling deuterons through magnetized Ni single crystal foil of 1−2 µm. It is proposed to use the reaction T(d, n)⁴He with polarized deuterons with an energy of 150 − 200 keV. For a nonchanneled beam (goniometer in a random position), tensor polarization measurements were carried out with a TiT target. Our result is P_zz = −0.20 ± 0.04. This result indicates that deuterium atoms which passed outside the channels also become polarized due to the capture of polarized electrons from the nickel crystal.