Abstract: In a technique for isotope enrichment a system for selectively exciting increased amounts of one isotope type in an environment of plural isotope types by the application of excitation energy at a plurality of frequencies which selectively excite the one isotope from its ground energy level and one or more typically low-lying excited levels.

Abstract: Apparatus for reducing convection current heat loss in an electron beam evaporator. A material to be evaporated (evaporant) is placed in the crucible of an electron beam evaporation source along with a porous mass formed of a powdered or finely divided solid to act as an impedance to convection currents. A feed system is employed to replenish the supply of evaporant as it is vaporized.

Abstract: A probe for detecting the evaporation rate of an electron beam evaporation source and for monitoring induced ionization of the vapor. A negatively biased electrode responds to ions in the vapor to measure the ion current density. The ions measured may result from the process of vaporization or from laser produced isotopically selective ionization. The probe provides a current output which is detected as an indication of vaporization or laser ionization rate.

Abstract: A system employing multiple, upper excitation levels in a technique for isotopically selective ionization to improve the ionization efficiency. In a technique which employs laser radiation to excite particles with isotopic selectivity, excitation is produced to a plurality of excited states below the ionization level with the result of increasing the number of available excited particles for ionization and thereby increasing the ionization cross-section for improved system efficiency.

Abstract: Frequency selective means, particularly for use in uranium enrichment by laser induced isotopically selective ionization to suppress unwanted lasing of the excited uranium medium. The frequency selective means, such as filters, are placed at intervals in a column of laser illuminated uranium vapor and are transmissive to the illuminating laser frequencies but nontransmissive to frequencies at which population inversions exist in the excited uranium. The filters limit the path length and correspondingly the gain in the excited uranium to prevent high intensity lasing by the uranium itself.

Abstract: An electron beam vapor source for use in laser enrichment of uranium and providing fast response intermittent vaporization to permit interruption of the enrichment process without wasting vapor or requiring long term reheating.

Abstract: In uranium enrichment, an electrode structure of thin, tensioned, parallel wires for use in applying an electric field to a region of a flowing uranium plasma including selectively ionized particles in order to accelerate the ionized particles for separate collection without interfering with the motion of neutral particles.

Abstract: Method and apparatus for separating isotope types by inducing an isotopically selective vibrational excitation of molecules containing at least one atom of the element type whose isotopes are to be separated. Vibrational excitation is induced in the molecules by finely tuned, narrow bandwidth laser radiation applied to a gaseous flow of the molecules. Isotopic separation of the molecules is achieved from the enhanced difference in diffusion rates for the molecules due to an alteration of the accommodation coefficients in the excited molecules.

Abstract: A floating mass or matrix for use in the melt of an electron beam vapor source to permit a wide latitude of evaporant level without necessary replenishment while at the same time reducing convective currents in the melt.

Abstract: Method and apparatus for separating selectively ionized particles from a plasma of moving particles by application of a magnetic field gradient in a direction to which the ionized particles are to be accelerated for collection. By creating conditions of adiabatic particle motion for charged particles in the magnetic field, the selectively ionized particles will be induced to follow the magnetic field lines in the direction of weaker field strength. The direction of this gradient is made different from the general direction of particle motion to permit extraction of the ions from the plasma. The extracted ions deposit on a collection surface in enriched proportions.

Abstract: A flashlamp pumped laser device employing a fluid material such as a dye solution for producing a laser beam, comprising an elongated hollow cell having an active or lasing region including a throat intermediate a continuously converging inlet chamber and a continuously diverging outlet chamber. The active region and the inlet and outlet chambers adjacent the active region are defined by two opposed inwardly curving walls formed of transparent material such as quartz. An elongated inlet manifold uniformly introduces the lasing fluid into the inlet chamber in a direction transverse to the laser output beam along the length of the active region. An elongated outlet manifold is disposed in the outlet chamber as and for the same purposes as the inlet pipe.

Abstract: A nozzle for a free jet dye laser wherein the nozzle orifice has an adjustable convex contour to permit realization of precisely plane parallel sides in the central jet region. A jet of this precision is desired to support a high quality laser beam for use in laser enrichment apparatus. The precise planar characteristic of the central portion of the jet is achieved by a narrowing of the central portion of the nozzle orifice. A set of adjustment screws are provided to define the specific contour of the narrowing to insure that the sides of the free jet are precisely plane parallel. A system is shown for detecting the degree to which the sides are plane parallel so that an optimum adjustment in the orifice can be achieved.

Abstract: A system for stabilizing the frequency of a laser employing the variation in position of interference patterns which results from a variation in laser beam frequency in passing through a Fabry Perot etalon filter. The system is particularly useful for maintaining strict frequency control at a particular frequency in the output of a tunable laser such as a dye laser for use in isotope separation.

Abstract: Method and apparatus for generating and accelerating ions in a vapor by use of relatively polarized laser radiation and a magnetic field. As applied to uranium isotope enrichment, a flowing uranium vapor has particles of the U.sub.235 isotope type selectively ionized by laser radiation and the ionized flow is subjected to a transverse gradient in a magnetic field. The magnetic field gradient induces an acceleration on the ionized particles of U.sub.235 which deflects them from their normal flow path toward a collecting structure. High magnetic field and corresponding high ion accelerations are achieved without loss in ionization selectivity by maintaining a polarization between the applied laser radiation and magnetic field which minimizes Zeeman splitting of the uranium energy states.

Abstract: In a system for isotope separation wherein a plasma of ions of one isotope type is created, method and apparatus for magnetically extracting the ions from the plasma without impairing the ionization selectivity and efficiency. In a particle flow of plural isotope types, radiant energy is applied to selectively excite and ionize ions of at least one isotope type without corresponding ionization of particles of other isotope types. A magnetic field is applied to divert the ions of the one isotope type sufficiently to permit separate collection of those ions without the other particle constituents of the flow. The system of the present invention balances the requirements for a high magnetic field to provide sufficient diversion before charge exchange with the requirement for a limited magnetic field to prevent interference with the selective ionization process due to Zeeman broadening of the isotope absorption lines.

Abstract: In a system for isotope enrichment, method and apparatus for separating particles of one isotope type from an environment containing particles of plural isotope types by ionizing the particles of said one isotope type and imparting to the electrons released from the ionized particles an energy substantially in excess of the thermal or background energy of the environment whereby these super energetic electrons expand away from the environment in the company of the corresponding ionized particles or trajectories substantially different from those of the remaining particles in the environment to permit separate collection of the particles of the one isotope type.

Abstract: A laser amplifier system having plural parallel paths for amplification of laser radiation from a single, stable laser oscillator. The plural paths of laser amplification are excited to produce sequential pulses of amplified output radiation that are interleaved by an optical combining system to produce a single path of amplified, pulsed radiation of increased repetition rate.

Abstract: For particle separation, a method and apparatus for using a wide angle radially expanding vapor of a particle mixture. In particular, selective ionization of one isotope type in the particle mixture is produced in a multichamber separator and the ionized isotope type is accelerated out of the path of the vapor expansion for separate collection.FIELD OF THE INVENTIONThis invention relates to isotope separation by selective ionization and in particular to a separation system making efficient use of an isotope source.BACKGROUND OF THE INVENTIONNearly all fission reactions utilizing the uranium isotope, U.sub.235, require a concentration of the U.sub.235 isotope greater than in the naturally occurring state. The process of enrichment whereby the concentration of U.sub.235 in natural or depleted uranium is raised to a desired level has been achieved in the past by many techniques which generally operate to separate U.sub.235 from the other uranium isotopes, chiefly U.sub.

Abstract: In a system for isotope separation, method and apparatus empolying crossed-field MHD particle accelerating techniques for collecting ions of a desired isotope after selective ionization of that isotope. In the plasma of electrons and selectively ionized atoms which results from selective isotope ionization, the ions are collected by inducing a circulation of the plasma electrons to provide a JXB relationship for MHD acceleration of the ions. The electron circulation enhances penetration of the plasma by the accelerating electric field and avoids the generation of large Hall voltages within the system as well as reducing the required magnitude of electrode currents.

Abstract: Method and apparatus for separating selectively ionized particles of one isotope type from the background environment of charged and neutral particles. In particular, a particle flow is generated which contains neutral particles of plural isotope types, as well as a number of ions of the various isotope types. It is desired to selectively ionize and separately collect only those particles of one isotope type and for this purpose, an acceleration is produced in the ions of the background environment prior to selective ionization of the desired isotope particles. After selective ionization, a further acceleration, in an opposite direction, is produced upon the charged particles which results in a deflection of the selectively ionized particles towards collection surfaces and restores to generally normal flow velocity and charge distribution, the ions from the background environment.