[en] The development of a cryopump is described for a 30 MV tandem Van de Graaf accelerator to control the vacuum pressure in the beam tube at the centre terminal when a gas stripper is in use. The system has been fully assembled and has been mechanically tested, the cryo pumps have been cooled to 180K and the insulation tested electrically to +- 20 kV between the pump elements and the biased stripper canal. (UK)