Abstract A light source apparatus for producing intense monochromatic light from a low-temperature plasma is disclosed. The light source apparatus comprises a housing member for confining a gas at subatmospheric pressure, the housing containing output means disposed to transmit light from the confined gas. At least one anode and one cathode are positioned within the gas in electrical circuit relationship with each other. First control means are provided for controlling the voltage applied to the anode and second control means independently control the temperature of the cathode by regulating the power supplied to it. The pressure of the gas is controlled by a third control means. An intense monochromatic light output is achieved by confining the gas in said chamber at a controlled predetermined reduced pressure, independently controlling the temperature of the electron emitting cathode by means of said second control means and applying a predetermined controlled low voltage to said anode by said first control means. An intermediate mode current is drawn from said cathode and produces in the confined gas a region having a high density of metastable atomic states. A lowtemperature, high-density plasma is continuously produced in said region and intense monochromatic light is emitted as a result of the recombination of ions and electrons in said plasma.
A method of producing intense, monochromatic very short wavelength ultraviolet light at a wavelength of 584-A from a contiNuous, low-temperature plasma comprising the steps of: a. confining helium gas at a controlled predetermined reduced pressure of 300 microns; b. independently controlling the temperature of an electron emitting cathode positioned in said gas to a constant temperature of at least 2,500* K. to produce an abundant supply of low-energy electrons; and c. applying a predetermined controlled low voltage of from 22 volts to 100 volts to an anode positioned in said gas in an electrical circuit relation with said cathode in which the internal resistance of the circuit is positive so as to draw an intermediate mode current of from 0.1 amperes to less than 100 amperes from said cathode without arcing in order to produce in said confined gas a region having a density of metastable atomic states above 1013 cm. 3 and to thus produce from them a low temperature, high-density plasma in said region, said intense monochromatic light at a wavelength of 584-A being emitted as a result of the recombination of ions and electrons in said plasma.
Claim 2
Independent Claim
190 words
A method of producing intense, monochromatic very short wavelength ultraviolet light at a wavelength of 584-A from a contiNuous, low-temperature plasma comprising the steps of: a. confining helium gas at a controlled predetermined reduced pressure of 300 microns; b. independently controlling the temperature of an electron emitting cathode positioned in said gas to a constant temperature of at least 2,500* K. to produce an abundant supply of low-energy electrons; and c. applying a predetermined controlled low voltage of from 22 volts to 100 volts to an anode positioned in said gas in an electrical circuit relation with said cathode in which the internal resistance of the circuit is positive so as to draw an intermediate mode current of from 0.1 amperes to less than 100 amperes from said cathode without arcing in order to produce in said confined gas a region having a density of metastable atomic states above 1013 cm. 3 and to thus produce from them a low temperature, high-density plasma in said region, said intense monochromatic light at a wavelength of 584-A being emitted as a result of the recombination of ions and electrons in said plasma.