ORBITRON PUMP WITH NITROGEN CRYOPANEL

The article presents the results of a study of the operation of a vacuum orbitron getter -ion pump (OGIP) with a nitrogen cryopanel. The design features of the orbitron pump and its operating modes are described. The composition of the residual atmosphere (MX7304A mass spectrometer) of the vacuum chamber during its pumping out by the OGIP to ultrahigh vacuum has been studied. It has been established that there are no heavy hydrocarbons in the chamber, and methane is not its main component and does not determine the ultimate pressure of the pump. In an insufficiently heated vacuum chamber at P = 2 center dot 10-8 Pa, the main component of the residual atmosphere is water vapor. Therefore, with further thorough degassing of the vacuum chamber, the use of OGIP with a nitrogen cryopanel makes it possible to obtain an ultra -high oil -free vacuum better than 10-8 Pa.