Cryopump Cooled with a Dual Heat Pipe

A cryopumping system providing a large pumping speed in the centre of a cyclotron accelerating chamber has been built. The cooling of the cryopanels supplied from cryorefrigerators located at some distance is efficiently transfered with a dual heat pipe operating with LN2 and LH2 circulating by gravity or even with He at moderate pressure in a natural convection mode. The design of the cryopanel is described. Performances for cooldown and steady state operation are given.