Abstract: A dyestuff of the formula (I) wherein D is a diazo component; R1 is hydrogen, (C1-C4)-alkyl, hydroxy, —NHCOR6 or —NHSO2R6; R2 is hydrogen, halogen or (C1-C4)-alkoxy; R3 is hydrogen or methyl; R4 is hydrogen, (C1-C6)-alkyl, substituted (C1-C6)-alkyl, (C2-C6)-alkyl, which is interrupted by 1, 2 or 3 heteroatoms wherein said heteroatoms are —0—, —S— or —NR7, substituted (C2-C6)-alkyl, which is interrupted by 1, 2 or 3 heteroatoms wherein said heteroatoms are —0—, —S— or —NR7, (C2-C6)-alkenyl, substituted (C2-C6)-alkenyl, benzyl or phenethyl; R5 is hydrogen or methyl; R6 is (C1-C4)-alkyl, phenyl or substituted phenyl; R7 is (C1-C4)-alkyl, phenyl or substituted phenyl; m is 0, 1 or 2; and n is 0 or 1. The invention further relates to use of the dyestuff and the process of making the dyestuff.

Abstract: A dyestuff of the formula (I) wherein D is a diazo component; R1 is hydrogen, (C1-C4)-alkyl, hydroxy, —NHCOR6 or —NH4SO2R6; R2 is hydrogen, halogen or (C1-C4)-alkoxy; R3 is hydrogen or methyl; R4 is hydrogen, (C1-C6)-alkyl, substituted (C1-C6)-alkyl, (C2-C6)-alkyl, which is interrupted by 1, 2 or 3 heteroatoms wherein said heteroatoms are —O—, —S— or —NR7, substituted (C2-C6)-alkyl, which is interrupted by 1, 2 or 3 heteroatoms wherein said heteroatoms are —O—, —S— or —NR7, (C2-C6)-alkenyl, substituted (C2-C6)-alkenyl, benzyl or phenethyl; R5 is hydrogen or methyl; R6 is (C1-C4)-alkyl, phenyl or substituted phenyl; R7 is (C1-C4)-alkyl, phenyl or substituted phenyl; m is 0, 1 or 2; and n is 0 or 1. The invention further relates to the use of the dyestuff and the process of making the dyestuff.

Abstract: An anode and a cathode are in an evacuated metal envelope comprising a radiation exit window and which carry a positive and a negative high voltage, respectively, with respect thereto during operation. The cathode, at its area which neighbors the radiation exit window, has a ridge segment which extends in the axial direction partially about the cathode filament. The segment shields the radiation exit window from the electrons emitted by the cathode to reduce heating of the window by the electrons.