I am planning to use a cryopump in a physical vapor deposition system to evaporate metals with high vapor pressure. I am particularly concerned with the metal vapor finding its way to the active adsorption surfaces in the cryopump and rendering it ineffective over time.

I would guess some of these concerns could be addressed by proper design so that the vacuum port is away from the line of sight of the evaporator. Operationally, I was considering getting the system to its baseline vacuum and shutting it off completely from the vacuum system. The hope is, since the system would be leak tight, I can perform the evaporation very quickly before the vacuum may deteriorate.Thus the cryopump would not be exposed to the metal vapor.

This is purely a  physical (thermal) vapor deposition and none of the reactants are gases.

Does anyone have ideas to almost eliminate this potential problem?