X-ray laser

A laser comprising:

• (a) an air-tight enclosure;
• (b) pumping means adapted to be coupled to said enclosure for evacuating said enclosure;
• (c) a working region within said enclosure wherein a population inversion may be produced in an active medium;
• (d) means for providing within said working region an active medium consisting substantially only of an atomic vapor, the constituents of which have the configuration 1s.sup.2 2s;
• (e) means for photoionizing said active medium to selectively produce a preferential population of ions in an excited metastable state;
• and
• (f) laser means having a pumping laser beam directed into said working region effective to antistokes Raman pump said ions, said pumping laser beam producing traveling wave stimulation in said ions to cause said ions to emit photons at a wavelength .lambda. and produce an output laser beam at said wavelength .lambda. substantially only in the direction of said traveling wave stimulation.

A laser comprising:

• (a) an air-tight enclosure;
• (b) pumping means adapted to be coupled to said enclosure for evacuating said enclosure;
• (c) a working region within said enclosure wherein a population inversion may be produced in an active medium;
• (d) means for providing within said working region an active medium comprising an atomic vapor, the constituents of which have the configuration 1s.sup.2 2s;
• (e) target material when heated being capable of radiating as a black body in the soft X-ray region of the spectrum;
• (f) means for producing a high energy short laser pulse;
• (g) means for directing said laser pulse on said target material, the energy level and length of said laser pulse being sufficient to cause said target material to radiate as a black body in the soft X-ray region of the spectrum, a portion of said radiation passing through said filter means and into said active medium and producing a population of ions in the excited metastable state;
• and
• (h) laser means having a pumping laser beam directed into said working region effective to antistokes Raman pump said ions, said pumping laser beam producing traveling wave excitation in said ions to cause said ions to emit photons at a wavelength .lambda. and produce an output laser beam at said wavelength .lambda. substantially only in the direction of said traveling wave excitation.