Atomic hydrogen source with direct helium cooling

Abstract

We have constructed a helium‐cooled atomic source where the discharge tube is placed immediately above the helium bath. The advantages of our system are simplicity, very short length and therefore small losses of the atomic beam, and the possibility of cryopumping molecular hydrogen. Preliminary tests show the feasibility of these principles. Further work is aimed at geometrical and thermal improvements, and possibly the addition of a spin selection magnet near the cooling tube.