Abstract: The wavelength of an optical pump beam is down converted to a longer wavelength in a Raman active gaseous medium by stimulated Raman scattering. The Raman active gaseous medium is contained in the space between a pair of optical reflectors of an optical resonator of the type for producing a focus of the optical beam energy at a point intermediate the length of the resonator within the Raman active medium to enhance conversion of pump energy into the output longer wavelength of the Stokes wave. The pump beam is directed into the optical resonator at an angle to the optical axis of the optical resonator such that the optical beam path is folded back and forth within the optical resonator to cause the beam spot to walk over the surfaces of the reflectors and out of the optical resonator.

Abstract: The type of conductor, its property, and if a metal, its type and cross-sectional area can be obtained from measurements made at different frequencies for the amount of unbalance created in a previously balanced stable coil detection system. The true resistive component is accurately measured and thus reflects only the voltage loss attributable to eddy currents caused by introduction of the test sample to the coil system. This voltage divided by corresponding applied frequency gives a curve which peaks at a frequency dependent upon type of conductor. For a metal this peak frequency is proportional to the samples resistivity divided by its cross-sectional area.

Abstract: The frequency of the output beam of a high power krypton fluoride laser is shifted by a plurality of Raman cells arranged successively in the path of the laser beams. These cells each contain a gas selected from the following gases: H.sub.2, HD, D.sub.2 and CH.sub.4, the combination of the gases used being chosen to provide a frequency shift of the beam so as to produce an output in the 330-355 nm range, which is suitable for use in photopredissociation of formaldehyde (HDCO) so as to produce heavy water (D.sub.2 O).

Abstract: To increase operating temperature, and hence vapor pressure, the arc tube ose to the arc, typically an inner arc tube, is at least partially frosted. The outer bulb which surrounds the inner arc tube may also be frosted. The lamps have low color temperature and good color rendering index at high luminous output. The fill preferably includes metal halides of rare earth metals, and/or mercury. The outer bulb is preferably in the form of a reflector bulb.

Abstract: A self shift type gas discharge panel in which pluralities of buses are respectively provided on a pair of substrates disposed opposite each other, electrodes are respectively connected to the buses and shift channels are set up in row and column directions with arrays of discharge points formed between the opposed electrodes of the substrates to enable shifting of a discharge spot in the row or column direction. On the substrates, the electrodes and the buses are so arranged as not to intersect each other, which allows ease in the manufacture of the discharge panel and ensures stable shifting of the discharge spot.

Abstract: A device is disclosed for producing intense 16 micron radiation in which stimulated rotational Raman scattering takes place in parahydrogen on an off-axis path between a pair of spherical mirrors.

Abstract: An intense broadband continuum light pulse of uniform spectral intensity and short time duration is generated. This continuum pulse is then downconverted in frequency to a region of interest, preferably in the infrared region, by applying it as a pump pulse to a molecular or atomic vapor so as to induce stimulated Raman scattering. The resulting Raman Stokes pulse surprisingly tends to have the same spectral bandwidth, intensity uniformity and time duration as the pump continuum pulse.The downconverted continuum pulse (the Raman Stokes pulse) is then used to probe a sample. The sample converts the uniform spectral intensity distribution of the probe pulse into a nonuniform spectral intensity distribution which contains the absorption spectrum of the sample. This spectrum pulse has the same spectral bandwidth and time duration as the Raman Stokes pulse and is finally upconverted in frequency to a region where the spectrum pulse can be conveniently recorded.

Abstract: Method and apparatus for the nondestructive determination of the amount and quantitative distribution of a paramagnetic additive such as gadolinia in nuclear fuel elements. Changes in paramagnetic susceptibility of the material in the element are detected as the element is passed through a constant magnetic field and compared to the changes in susceptibility produced by a standard element of known additive content.

Abstract: Shifted Raman radiation for an all-hot Raman discharge cell is produced by external laser pumping of a metal halide medium in the cell during an afterglow period following dissociation of the metal halide medium into metal atoms and before recombination to form the original species of the metal halide medium.

Abstract: An apparatus for counting and sizing particles suspended in a liquid electrolyte, having first and second vessels for first liquid electrolyte having particles to be counted and sized suspended therein; and for particle-free second liquid electrolyte, respectively; first and second electrodes immersed in the first and second liquid electrolytes, respectively; an orifice having upstream and downstream sides and constituting a first particle-observing location in fluid flow connection on its upstream side with the first vessel and sized to allow one particle at a time to pass therethrough; and a fluid flow passage connecting with the downstream side of the orifice for carrying liquid electrolyte and particles away from the orifice to a second particle-observing location; and sized to carry the particles in the same sequence of flow as that in which they pass through the orifice to facilitate observation in that order at the second particle-observing location.

Abstract: An elastic surface wave device, especially amplifier which includes input and output means for electrical signals provided so as to be spaced on a surface of a piezoelectric material which composes a laminate in combination with a semiconductor, and an electrode provided in a surface signal wave propagation path between said input and output means for application of a d.c. bias voltage and supply of a pumping power.

Abstract: It has been discovered that plasma containment by a chamber having multi-pole magnetic cusp reflecting walls in combination with electronic injection for electrostatic containment provides the means for generating magnetic field free quiescent plasmas for practical application in ion-pumps, electronic switches, and the like. 1250 "Alnico V" magnets 1/2".times.1/2".times.11/2" provide containment in one embodiment. Electromagnets embodying toroidal funneling extend the principle to fusion apparatus.

Abstract: A digital transducer for rotary shaft speed has a resolution which varies automatically with shaft speed. A wheel, keyed to the shaft, is partitioned into plural sectors by angularly spaced notches, the angular spacing between successive notches increasing in a fixed ratio to define respective preselected speed zone within a range of such zones. A first counter is arranged to count fixed frequency clock pulses and to be reset after each shaft revolution. A variable frequency pulse train is generated by a sensor arranged to sense the passage of each notch. Upon receipt of each pulse in the variable frequency pulse train, a comparator compares the count in the first counter with stored reference numbers which are related to the clock pulse frequency and to the ratio of successive angles between the notches. A second counter, also reset once during each shaft revolution, counts pulses in the variable frequency pulse train.

Abstract: A multistaged Stokes injected Raman capillary waveguide amplifier for providing a high gain Stokes output signal. The amplifier uses a plurality of optically coupled capillary waveguide amplifiers and one or more regenerative amplifiers to increase Stokes gain to a level sufficient for power amplification. Power amplification is provided by a multifocused Raman gain cell or a large diameter capillary waveguide. An external source of CO.sub.2 laser radiation can be injected into each of the capillary waveguide amplifier stages to increase Raman gain. Devices for injecting external sources of CO.sub.2 radiation include: dichroic mirrors, prisms, gratings and Ge Brewster plates. Alternatively, the CO.sub.2 input radiation to the first stage can be coupled and amplified between successive stages.

Abstract: An electromechanical positioner indicator is provided which comprises first and second relatively movable parts, the first part including two oppositely facing surfaces which are everywhere equidistant and the second part including two surfaces which are everywhere equidistant and which are everywhere equispaced from and lie, closely adjacent to respective ones of the two surfaces of the first part. A first coil, preferably in printed circuit form, is secured to the first part and sensing coils, also preferably in printed circuit form, are secured to each of the two surfaces of the second part. The inductive coupling between the coils is dependent on the relative positions of the parts and thus the output of the sensing coils provides an indication of position. In one embodiment, the surfaces in question are formed by cylinders and in another, the first part is a disc and the main coil comprises an annulus. Particular coil and coil conductor shapes are also disclosed.

Abstract: A device for producing stimulated Raman scattering of CO.sub.2 laser radiation by rotational states in a diatomic molecular gas utilizing a Stokes injection signal. The system utilizes a cryogenically cooled waveguide for extending focal interaction length. The waveguide, in conjunction with the Stokes injection signal, reduces required power density of the CO.sub.2 radiation below the breakdown threshold for the diatomic molecular gas. A Fresnel rhomb is employed to circularly polarize the Stokes injection signal and CO.sub.2 laser radiation in opposite circular directions. The device can be employed either as a regenerative oscillator utilizing optical cavity mirrors or as a single pass amplifier. Additionally, a plurality of Raman gain cells can be staged to increase output power magnitude. Also, in the regenerative oscillator embodiment, the Raman gain cell cavity length and CO.sub.2 cavity length can be matched to provide synchronism between mode locked CO.sub.

Abstract: A device for converting the frequency of coherent light from a prescribed wavelength range characterized by utilizing at least one crystal consisting of a nonlinear optical material. In order to obtain phase adjustment or phase matching, the device of the present invention provides a crystal possessing a property, which, at least for a specific wavelength of .lambda..sub.u from a wavelength range, the phase adjustment angle .theta..sub.0 and the phase adjustment temperature of T.sub.0 do not depend upon the wavelength at least in the first approximation. Thus, known methods of phase adjustments such as continuously rotating the crystal and/or changing the temperature are not required to adjust the phase when the frequency of the wavelength is changed within certain limits.

Abstract: A pair of electrical prods along with a powder supply gun are incorporated in a single portable frame member which is easily insertable into a relatively small blind bore; prod tension against the bore wall is adjustable by varying spring plunger tension; incorporated in the apparatus is the ability to locate indications in all directions by provision of both linear and axial heads which interchange on the same frame or handle; powder is applied to the area to be inspected while current is flowing into the prods, and the powder gun can be rotated and retracted as required to provide full coverage of the area to be inspected with powder.

Abstract: An eddy current flaw detector is held in a mounting block by a spring bias, the mounting block is selectively rotatable about a shank member for varying the radius of the detector as the shank rotates about a pivot point, turned by an electric drive mechanism.

Abstract: A gas discharge lamp having a glass tube with preformed sintered glass bodies sealed to each end with each body carrying at least one connector pin for an electrode so that at least one electrode is disposed and supported adjacent each end of the discharge tube. The glass bodies may be sealed in the discharge tube either by glass solder, an organic adhesive or a combination of both.