公开(公告)号：US3902090A

公开(公告)日：1975-08-26

申请号：US33446673

申请日：1973-02-21

Applicant: PHILIPS CORP

Inventor： EKKELBOOM TJEPKE HENDRIK ,  VRIEZE WUBBE

IPC: H01J61/073 ,  H01J61/98 ,  H01J1/14 ,  H01J1/28

CPC classification number: H01J61/98 ,  H01J61/0732

Abstract: A short-arc gas discharge lamp having a discharge vessel provided with a gas filling in which the discharge takes place, and with two electrodes of a high melting point metal facing each other. The end of at least one of the electrodes facing the discharge is conical and has a recess located on the axis of the cone, which recess accommodates a quantity of thorium metal. The recess extends to such a distance from the closed apex of the cone that during operation of the lamp transport of thorium metal to the apex of the cone is mainly effected by means of diffusion through the electrode material.