Abstract: The generation of ultrabright, multikilovolt coherent tunable x-radiation resulting from amplification on hollow atom transition arrays is described. Amplification has been demonstrated by physical evidence including (a) the observation of selected spectral components of several Xeq+ hollow atom transition arrays (q=30, 31, 32, 34, 35, 36, 37) radiated axially from confined plasma channels, (b) the measurement of line narrowing that is spectrally correlated with the amplified transitions, (c) evidence for spectral hole-burning in the spontaneous emission, a manifestation of saturated amplification, that corresponds spectrally with the amplified lines, and (d) the detection of an intense narrow (??x˜0.2 mr) directed beam of radiation in the far field of the source.

Abstract: The generation of ultrabright, multikilovolt coherent tunable x-radiation resulting from amplification on hollow atom transition arrays is described. Amplification has been demonstrated by physical evidence including (a) the observation of selected spectral components of several Xeq+ hollow atom transition arrays (q=30, 31, 32, 34, 35, 36, 37) radiated axially from confined plasma channels, (b) the measurement of line narrowing that is spectrally correlated with the amplified transitions, (c) evidence for spectral hole-burning in the spontaneous emission, a manifestation of saturated amplification, that corresponds spectrally with the amplified lines, and (d) the detection of an intense narrow (&dgr;&thgr;x˜0.2 mr) directed beam of radiation in the far field of the source.

Abstract: An apparatus and method for the generation of ultrabright multikilovolt x-rays from saturated amplification on noble gas transition arrays from hollow atom states is described. Conditions for x-ray amplification in this spectral region combine the production of cold, high-Z matter, with the direct, selective multiphoton excitation of hollow atoms from clusters using ultraviolet radiation and a nonlinear mode of confined, self-channeled propagation in plasmas. Data obtained is consistent with the presence of saturated amplification on several transition arrays of the hollow atom Xe(L) spectrum (&lgr;˜2.9 Å). An estimate of the peak brightness achieved is ˜1029 &ggr;·s−1·mm−2·mr−2 (0.1% Bandwidth)−1, that is ˜105-fold higher than presently available synchotron technology.

Abstract: An apparatus and method for the generation of ultrabright multikilovolt x-rays from saturated amplification on noble gas transition arrays from hollow atom states is described. Conditions for x-ray amplification in this spectral region combine the production of cold, high-Z matter, with the direct, selective multiphoton excitation of hollow atoms from clusters using ultraviolet radiation and a nonlinear mode of confined, self-channeled propagation in plasmas. Data obtained is consistent with the presence of saturated amplification on several transition arrays of the hollow atom Xe(L) spectrum (&lgr;˜2.9 Å). An estimate of the peak brightness achieved is ˜1029 &ggr;·s−1·mm−2·mr−2 (0.1% Bandwidth)−1, that is ˜105-fold higher than presently available synchotron technology.

Abstract: Apparatus and method for locally generating hyperthermia-induced coagulation necrosis in tissue masses located deeply within the body of a subject. High energy laser radiation is introduced into the target tissue mass using an optical fiber inserted into a metallic cannula through which a suitable fluid is coaxially flowed. A combination of the fluid flow and the slow withdrawal of the cannula/fiber combination during therapy protects the optical fiber tip, thereby preserving its energy transmission characteristics. After establishment of a small fluid bolus in front of the fiber tip, fluid flow which is approximately proportionate to the laser energy employed has been found to be most effective in this regard.

Abstract: Apparatus and method for generating prompt X-radiation from gas clusters. The present invention includes the excitation of inner-shell electrons in the atoms comprising gas clusters using intense ultraviolet laser radiation, thereby producing intense, prompt X-ray emission from the ensemble. Clusters enable atomic excitation rates to achieve the high values characteristic of condensed matter while simultaneously eliminating, through local rapid expansion to low particle density, undesirable collisional interactions that would establish equilibrium conditions in the excited material, and effectively destroy the inner-shell specificity of the excitation. By choosing the atomic species in the cluster, the laser intensity and wavelength, and the cluster size, one can determine the wavelength of X-radiation emitted from the clusters. Moreover, by selecting the energy levels involved in the excitation process, one can produce a population inversion having significant gain and suitable for lasing.

Abstract: Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.

Abstract: Apparatus and method for locally generating hyperthermia-induced coagulation necrosis in tissue masses located deeply within the body of a subject. High energy laser radiation is introduced into the target tissue mass using an optical fiber inserted into a metallic cannula through which a suitable fluid is coaxially flowed. A combination of the fluid flow and the slow withdrawal of the cannula/fiber combination during therapy protects the optical fiber tip, thereby preserving its energy transmission characteristics. After establishment of a small fluid bolus in front of the fiber tip, fluid flow which is approximately proportionate to the laser energy employed has been found to be most effective in this regard.

Abstract: Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. For example, by using a nickel reference scatter at 4.5 nm, sufficient reference illumination is provided over a wide enough angle to allow similar resolution in both transverse and longitudinal directions. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.

Abstract: Method and apparatus for producing laser radiation by two-photon optical pumping of an atomic or molecular gaseous medium and subsequent lasing action. A population inversion is created as a result of two-photon absorption of the gaseous species. Stark tuning is utilized, if necessary, in order to tune the two-photon transition into exact resonance. In particular, gaseous ammonia (NH.sub.3) or methyl fluoride (CH.sub.3 F) is optically pumped by a pair of CO.sub.2 lasers to create a population inversion resulting from simultaneous two-photon excitation of a high-lying vibrational state, and laser radiation is produced by stimulated emission of coherent radiation from the inverted level.

Abstract: An electron beam of energy typically 100 keV excites a fluorescer gas which emits ultraviolet radiation. This radiation excites and drives an adjacent laser gas by optical pumping or photolytic dissociation to produce high efficiency pulses.The invention described herein was made in the course of, or under, United States Energy Research and Development Administration Contract No. W-7405-Eng-48 with the University of California.