Gas from angled jets in a conical array bounces off the sample in a high-pressure stream, effectively centered in a duct leading to an optical-measurement chamber. A glow discharge, in the high-pressure zone where gas hits the sample, provides effective sample bombardment. Pulsed high-energy presputtering quickly bares the sample interior for analysis. Dislodged atoms flow with the gas (whose centering keeps an arrestor recess clear or obviates the need for a recess) to the measurement chamber, where the stream is bent into a long path for coaxial measurement viewing. To lessen turbulence losses, a contoured guide leads the stream into the coaxial path. The stream can be split into two opposed substreams to double the absorption pathlength. Discharge current is adjusted to use a linear part of the absorbance curve; or servocontrolled to hold absorbance at an ideal value--the current itself serving as an index of concentration. A water-cooled cathode plate firmly contacts the front of the sample (around the sputter area). The arrestor is mounted resiliently: it too makes firm sample contact. Servocontrol of gas pumping and/or supply rate stabilizes pressure, absorbance, or both. Emission is monitored to normalize (or prevent) sputtering-rate variations. A baffle in the optical chamber deters atomic coating of end windows.