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Billman, K. W.

Publications and source records attributed to Billman, K. W..

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Second NASA Conference on Laser Energy Conversion

The possible transmission of high power laser beams over long distances and their conversion to thrust, electricity, or other useful forms of energy is considered. Specific topics discussed include: laser induced chemistry; developments in photovoltaics, including modification of the Schottky barrier devices and generation of high voltage emf'sby laser radiation of piezoelectric ceramics; the thermo electronic laser energy converter and the laser plasmadynamics converters; harmonic conversion of infrared laser radiation in molecular gases; and photon engines.

Billman, K. W.↗
NASA NTRS1976

IR pumped third-harmonic generation and sum-frequency generation in diatomic molecules

The potential efficiency of using nonlinear up-conversion techniques for the high efficiency type lasers (CO,CO2, and chemical) is assessed. Results indicate that: the small pump photon energy necessitates the use of molecular media for conversion if resonance enhancement is to be used and that molecular systems present several problems. These difficulties include: their levels are complex; their transition probabilities are often unknown; and the oscillator strengths among vibrational levels in the ground electronic state of a molecule are much smaller than those among electronic states of an atom, thus limiting the magnitude of nonlinear interactions. It is shown that this problem can be eliminated by making use of vibronic transitions which, being primarily electronic transitions have much larger matrix elements and efficient conversion can be achieved with molecular systems.

She, C. Y.↗
NASA NTRS1975

Vibrational energy exchange in CO-CO collisions at low temperature

The V-V exchange rates for CO in the ground electronic state have been measured at a temperature of 75 K. The rates determined were for the processes CO(nu = n) + CO(nu = 0) yields CO(nu = n - 1) + CO(nu = 1) - increment E, with n lying in the closed interval from 2 to 8. The values obtained are close to published 100 K data, thus indicating an insensitivity to temperature. It appears that multirotational quantum jumps may be important in explaining the measured rates.

Gower, M. C.↗
NASA NTRS1975

Laser energy conversion

Laser radiation could possibly provide a feasible approach for the transmission of energy between stations and vehicles in space and on earth. The transmitted energy could be used for the operational requirements of the receiving space station, lunar base, or spacecraft. In addition, laser energy could also be employed to provide power for the propulsion of vehicles in space. The present status of development regarding the various technological areas involved in an implementation of these objectives is examined, taking into account the possibility of further advances needed to satisfy the technical requirements. Attention is given to laser-induced chemistry for converting the radiation energy into chemical energy. Other subjects considered are related to photovoltaics, optical diodes, thermo-electronics, laser rockets, and photon engines.

Billman, K. W.↗
NASA NTRS1975

Infrared-pumped third-harmonic and sum-frequency generation in diatomic molecules

Using molecular hydrogen as a model system, we present a calculation which demonstrates the feasibility of efficient third-harmonic and sum-frequency generation of IR laser radiation by diatomic molecular gases. A conversion efficiency of 10% without phase matching is achievable with a modest laser intensity of about 20 MW/sq cm. In addition to a two-photon resonance, the efficient conversion depends on a mechanism which makes use of virtual vibronic transitions exclusively. Possible methods for phase matching are also suggested.

She, C. Y.↗
NASA NTRS1975

Infrared tunable laser: A concept

Apparatus in which laser wavelengths of two dyes are mixed in intracavity, nonlinear crystal provides intense source of coherent laser radiation which is tunable from visible through infrared wavelengths of electromagnetic spectrum.

Billman, K. W.↗
NASA NTRS1974

Absorption of laser radiation in a H-He plasma. II - Experimental measurement of the absorption coefficient

The absorption coefficients of 0.633-, 1.15-, and 3.39-micron laser radiation for a homogeneous H-He plasma have been measured in the temperature range from 12.2 to 21.7 (x 1000 K) and in the electron number density range 0.45 to 6.5 (x 10 to the 17th power per cu cm). Good agreement is found between the experimentally determined total absorption for each of the wavelengths and that calculated from theory. Furthermore, because the 3.39-micron absorption is dominated by inverse bremsstrahlung, while the 0.633-micron absorption is dominated by photoionization and resonance absorption, the experiment indicates a correct assessment by the theory of these individual absorption mechanisms.

Billman, K. W.↗
NASA NTRS1973

Cautionary note concerning the CuSO4 X-ray laser

For the so far unconfirmed lasing action claimed by Kepros et al. (1972) to have been obtained by focusing a 1.06-micron radiation of a q-switched Nd(3+) glass laser to a small cylindrical volume inside a CuSO4-doped gelatin medium supported between two glass plates, an alternate explanation is proposed that does not depend on the assumption of laser action in copper. The proposed explanation shows how collimated X-ray beams might be created under the experimental conditions described by Kepros et al.

Billman, K. W.↗
NASA NTRS1973

Alignment apparatus using a laser having a gravitationally sensitive cavity reflector

A description is given of a device for determining a true gravitational vertical. The apparatus is composed of a vertically disposed laser with a gravitationally sensitive lower regeneration reflector. The reflector enables an output beam to be developed only when the optical axis of the laser is disposed normal to the gravitationally sensitive reflective surface. In an alternative embodiment, the devices is combined with a servo system to provide a gravitationally stabilized horizontal platform.

Billman, K. W.↗
NASA NTRS1973

Infrared tunable laser

A tunable laser apparatus is reported with a first wavelength selective reflector and a second wavelength selective reflector forming one end of an optical cavity, and a third wavelength selective reflector forming the other end of an optical cavity. A first lasable dye solution develops radiation of a wavelength selected by the first reflector and a second lasable dye solution develops radiation of a wavelength selected by the second reflector and a non-linear mixing crystal disposed within the optical cavity. The selected radiation is passed through the nonlinear mixing crystal causing it to develop radiation of a third wavelength which is transmitted out of the optical cavity through the third reflector.

Billman, K. W.↗
NASA NTRS1973

Measurement of plasma temperature and density using laser absorption

A laser radiation absorption technique, suitable for temporal measurement of the electron density, the temperature, or a simultaneous determination of both, in an LTE plasma, is discussed. The theoretical calculation of the absorption coefficient for a hydrogen plasma is outlined; some results are presented for visible wavelengths. Measurements of electron density and temperature are presented and shown to be in good agreement with those values obtained by other methods. Finally, the possible use of the argon ion laser for simultaneous electron density and temperature measurement is discussed, and the theoretical curves necessary for its application to hydrogen plasma diagnostics are shown.

Billman, K. W.↗
NASA NTRS1972

Measurement of electron density and temperature in plasmas

Application of two laser wavelengths passing through plasma measures electron density and temperature. Function depends on determining absorption of light at two wavelengths. Nature of reaction is explained and schematic diagram of equipment is included.

Billman, K. W.↗
NASA NTRS1972

Comparison of measured and theoretical inverse bremsstrahlung and photoionization absorption of infrared radiation in a H-He plasma.

The absorption coefficients of 1.15- and 3.39-micrometer radiation for a homogeneous H-He plasma have been measured in a temperature and electron density range where the major absorption mechanisms are electron-ion inverse bremsstrahlung and neutral-atom photoionization. Measurements were made behind both the incident and reflected shock waves in a driven tube by recording the laser intensity transmitted along the tube diameter as a function of time. The measured values compare well with those obtained from theoretical calculations for a gas in thermodynamic equilibrium.

Billman, K. W.↗
NASA NTRS1971

True vertical laser

True vertical laser application for precision vertical alignment of large structures, using mercury mirror

Billman, K. W.↗