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Becker, D. G.

Publications and source records attributed to Becker, D. G..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Luminous efficiency measurements for silicon and aluminum simulated micrometeors

Laboratory measurements on simulated silicon and aluminum micrometeors in an air atmosphere have produced values for the elemental photographic luminous efficiencies of silicon over a velocity range 13-48 km/sec and of aluminum over a range 12-42 km/sec. The photographic luminous efficiency of both elements first increases with increasing velocity, then reaches a peak and declines. Supplementary measurements on Si and Al in atmospheres of O2 and N2 support the air results.

Becker, D. G.↗
NASA NTRS1973

A linear accelerator for simulated micrometeors.

Review of the theory, design parameters, and construction details of a linear accelerator designed to impart meteoric velocities to charged microparticles in the 1- to 10-micron diameter range. The described linac is of the Sloan Lawrence type and, in a significant departure from conventional accelerator practice, is adapted to single particle operation by employing a square wave driving voltage with the frequency automatically adjusted from 12.5 to 125 kHz according to the variable velocity of each injected particle. Any output velocity up to about 30 km/sec can easily be selected, with a repetition rate of approximately two particles per minute.

Slattery, J. C.↗
NASA NTRS1973

Determination of meteor parameters using laboratory simulation techniques

Atmospheric entry of meteoritic bodies is conveniently and accurately simulated in the laboratory by techniques which employ the charging and electrostatic acceleration of macroscopic solid particles. Velocities from below 10 to above 50 km/s are achieved for particle materials which are elemental meteoroid constituents or mineral compounds with characteristics similar to those of meteoritic stone. The velocity, mass, and kinetic energy of each particle are measured nondestructively, after which the particle enters a target gas region. Because of the small particle size, free molecule flow is obtained. At typical operating pressures (0.1 to 0.5 torr), complete particle ablation occurs over distances of 25 to 50 cm; the spatial extent of the atmospheric interaction phenomena is correspondingly small. Procedures have been developed for measuring the spectrum of light from luminous trails and the values of fundamental quantities defined in meteor theory. It is shown that laboratory values for iron are in excellent agreement with those for 9 to 11 km/s artificial meteors produced by rocket injection of iron bodies into the atmosphere.

Friichtenicht, J. F.↗
NASA NTRS1972

Investigation of high speed phenomena

Experimental research is reported for laboratory simulation of meteors and meteoroid impacts on solid surfaces. Two types of mass measurements are discussed: impact ionization risetime effect, and luminous efficiency measurements.

Becker, D. G.↗