schulz-du bo

Claim 1

A TRAVELLING WAVE MASER COMPRISING A SECTION OF HOLLOW, CONDUCTIVELY BOUNDED RECTANGULAR WAVEGUIDE HAVING A PAIR OF NARROW AND A PAIR OF WIDE WALLS, A COPLANAR ARRAY OF PARALLEL METALLIC POSTS LOCATED BETWEEN SAID WIDE WALLS AND LONGITUDINALLY DISTRIBUTED ALONG SAID GUIDE, EACH OF SAID POSTS HAVING ONE END SHORT-CIRCUITED TO ONE OF SAID NARROW WALLS AND THE OTHER END OPEN-CIRCUITED TO FORM A COMB-LIKE STRUCTURE, AT LEAST ONE SLAB OF MASER MATERIAL POSITIONED ADJACENT THE COMB-LIKE STRUCTURE AND EXTENDING LONGITUDINALLY ALONG SAID GUIDE OVER AN INTERVAL AT LEAST COEXTENSIVE WITH SAID STRUCTURE, SAID MATERIAL HAVING A MAXIMUM HEIGHT WHICH SUBSTANTIALLY FILLS THE REGION BETWEEN SAID POSTS AND A WIDE WALL OF SAID GUIDE FROM A FIRST POINT ADJACENT SAID SHORT-CIRCUITED END OF SAID POSTS TO A SECOND POINT INTERMEDIATE ALONG SAID POSTS, SAID HEIGHT GRADUALLY TAPERING OFF OVER AN INTERVAL FROM SAID SECOND POINT TO A THIRD POINT ALONG SAID POSTS NEAR THE OPEN-CIRCUITED END TO A REDUCED HEIGHT THAT IS LESS THAN APPROXIMATELY 30 PERCENT OF THE MAXIMUM HEIGHT, SAID INTERVAL CONSITITUTING BETWEEN 20 AND 50 PERCENT OF THE OVERALL WIDTH OF THE MASER MATERIAL AND MEANS FOR ESTABLISHING A STEADY MAGNETIC FIELD THROUGH SAID MATERIAL.