Gas-discharge lamp for producing modulated atomic resonance radiation

Claim 2

A gas-discharge lamp for producing modulated atomic resonance radiation comprising a hermetically sealed cylindrical envelope having a window at one end to pass said radiation, two electrodes within said envelope for maintaining a positive column discharge along the longitudinal axis of said envelope, a hollow cylindrical sputtering electrode containing an element the desired resonance radiation characteristics of which is to be produced, said sputtering electrode being positioned between said electrodes to coaxially surround said discharge, means for periodically varying the polarity of the voltage to said sputtering electrode to produce intermittent resonance radiations, and a ring surrounding said discharge between the electrode at the window end and said sputtering electrode to restrict ionization within said sputtering electrode and produce desired resonance radiation along said longitudinal axis, said ring extending up to the vicinity of the sputtering electrode, and having an inner diameter smaller than the inner diameter of said sputtering electrode and a length at least equal to the inner diameter of said ring.

Claim 3

A gas-discharge lamp as claimed in claim 1 wherein means for periodically varying the voltage of said sputtering electrode comprises a negative voltage pulse generator.

Claim 4

A gas-discharge lamp as claimed in claim 2 wherein said negative voltage pulse generator has a pulse repetition frequency between 5 and 5000 Hz.

Claim 5

A gas-discharge lamp as claimed in claim 2 further comprising at least one additional sputtering electrode and ring positioned between said electrodes.

Claim 6

Apparatus for measuring absorption of modulated resonance radiation which comprises: a gas-discharge lamp for producing modulated resonance radiation, said lamp comprising a hErmetically sealed cylindrical envelope having a window at one end for passing said radiation, two electrodes within said envelope for maintaining a positive column discharge along the longitudinal axis of said envelope, a plurality of hollow cylindrical sputtering electrodes having elements, the desired resonance radiation characteristics of which is to be produced, said sputtering electrodes being positioned between said electrodes to coaxially surround said discharge, and a plurality of rings surrounding said discharge between adjacent sputtering electrodes and between said electrodes for maintaining a positive column discharge and adjacent sputtering electrodes to restrict ionization within said sputtering electrodes and produce desired resonance radiation along said longitudinal axis, said rings, extending up to the vicinities of the sputtering electrodes, having inner diameter smaller than the inner diameters of the adjacent sputtering electrodes and lengths at least equal to the inner diameters of said ring; voltage generating means for producing voltages having varying polarities, switching means connected between said voltage generating means and the sputtering electrodes of said gas-discharge lamp for selectively applying the varying voltage polarities to each of said sputtering electrodes to produce intermittent resonance radiation during predetermined measuring intervals; thermal means for producing an atomic vapor representing elemental constituents of an unknown sample, positioned in the path of said produced resonance radiation; detecting means for producing electric signals representative of the resonance radiation transmitted through the atomic vapor; amplifying means for eliminating error signals from said produced electrical signals; gating means synchronized with said switching means to pass only amplified signals corresponding to resonance radiations from the selected sputtering electrode during each measuring interval; integrating means for converting said gated signals to voltages proportional to the resonance radiation absorbed during said measuring interval; and automatic means for reading out said voltage measurement during said measuring interval.

Claim 7

Apparatus for measuring absorption of modulated resonance radiation which comprises: a gas-discharge lamp for producing modulated resonance radiation, said lamp comprising a hErmetically sealed cylindrical envelope having a window at one end for passing said radiation, two electrodes within said envelope for maintaining a positive column discharge along the longitudinal axis of said envelope, a plurality of hollow cylindrical sputtering electrodes having elements, the desired resonance radiation characteristics of which is to be produced, said sputtering electrodes being positioned between said electrodes to coaxially surround said discharge, and a plurality of rings surrounding said discharge between adjacent sputtering electrodes and between said electrodes for maintaining a positive column discharge and adjacent sputtering electrodes to restrict ionization within said sputtering electrodes and produce desired resonance radiation along said longitudinal axis, said rings, extending up to the vicinities of the sputtering electrodes, having inner diameter smaller than the inner diameters of the adjacent sputtering electrodes and lengths at least equal to the inner diameters of said ring; voltage generating means for producing voltages having varying polarities, switching means connected between said voltage generating means and the sputtering electrodes of said gas-discharge lamp for selectively applying the varying voltage polarities to each of said sputtering electrodes to produce intermittent resonance radiation during predetermined measuring intervals; thermal means for producing an atomic vapor representing elemental constituents of an unknown sample, positioned in the path of said produced resonance radiation; detecting means for producing electric signals representative of the resonance radiation transmitted through the atomic vapor; amplifying means for eliminating error signals from said produced electrical signals; gating means synchronized with said switching means to pass only amplified signals corresponding to resonance radiations from the selected sputtering electrode during each measuring interval; integrating means for converting said gated signals to voltages proportional to the resonance radiation absorbed during said measuring interval; and automatic means for reading out said voltage measurement during said measuring interval.

Claim 8

Apparatus for measuring absorption of resonance radiations as claimed in claim 5 wherein said plurality of sputtering electrodes comprise elements having different resonance radiation characteristics.

Claim 9

Apparatus for measuring absorption of resonance radiations as claimed in claim 5 further comprising light filtering means for the radiations from said thermal means.