ANALYSIS AND REDUCTION OF DATA RECORDED UNDER PROJECT COWBOY. Final Report. Project VELA UNIFORM

Technical Report · Tue Jul 11 04:00:00 EDT 1961

OSTI ID:4808922

Wylie, R W

The analyses conducted under Project Cowboy were performed on eight chemical detonations. The shots consisted of 200-, 500-, and 1000-pound decoupled shots in a 30-ft spherical cavity. An additional decoupled 1000-pound shot was detonated in a 12-ft spherical cavty. Tamped shots had yields of 200, 500, and two 1000 pounds. Analyses from the Cs-filjed thermionic converter can o~cur. A simpl~ model for neutralization is assumed in which all ions are created at the cathode by surface ionization and no ion trapping o~curs. Thc calculations indicate that ion neutralization of an electron eimission of 1 amp/ cm/ or greater ~an only bc achieved at ~athode tcniperatures below 1500-C by using high Cs pressures (e.g., l0 mm Hg or more) where electron scattering by Cs atoms may be serious. Expcriniental data for the neutralization of a convert~r using a Cs-on-W data recorded indicated the following results: the predominant energy of the decoupled signals is concentrated in the first few arrivals whereas the tamped signals are characterized by many arrivals of rather constant amplitude; the 500- and 1000-pound tamped and decoupled shots revealed that the tamped shots transmitted a greater quantity of low frequency energy than the decoupled shots; the total seismic energy is partitioned differently between the various modes of propagation for tamped and decoupled shots and is a function of the size of the explosive and cavity; the effect of decoupling can be thought of as a linear filtering of the tamped signal response; and amplitude density ratios computed from spectral response characteristics indicated that the decoupling is a function of frequency, shot size, and distance from the source. Seismic attenuations are usually frequency dependent; therefore, the decoupllng analysis presented is based on defining decoupling as the amplitude density ratio as a function of frequency. Depending on the time length and area of the seismogram from which the samples are selected, the ratios of the average amplitude response can describe the decoupling as determined for the first arriving refractions, body wave segment of the record, or the total seismic signal return. These ratios are only dependent upon the seismic signal and noise variations. The analysis included energy density spectra of signals and power density spectra of the noise samples for the 500- and 1000-pound decoupled and tamped events. Time samples were analyzed, e.g., 0.256-second samples of the first arrivals and 2.048- second samples of noise and signal. Surface wave energy is not included in the analysis. Seventeen shots were detonated under Project Cowboy in an effort to establish the decoupling capahilities of cavity source environments for nuclear detonations. Texas Instruments participation was to determine the characteristics, and analyze the data obtained, of decoupled shots, seismometer coupling, environment, an:d travel paths relative to chemical explosions in spherical cavities. The test shots were conducted in early 1960. Special research equipment built with company funds for use in seismic research was used in the analysis and reduction of data gathered. S-41 seismometers having a frequency of 4 cps were used to monitor the eight shots. (auth)

• Research Organization: Texas Instruments, Inc., Dallas
• NSA Number: NSA-16-010662
• OSTI ID: 4808922
• Report Number(s): AFCRL-802; AD-261745
• Country of Publication: United States
• Language: English

Related Subjects

CHEMICAL REACTIONS
ENERGY
ENVIRONMENT
EXPLOSIONS
EXPLOSIVES
FREQUENCY
MASS
MOTION
NUCLEAR EXPLOSIONS
PHYSICS
PROJECT COWBOY
SEISMOLOGY
SPHERES
TUBES