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Peterson, R. S.

Publications and source records attributed to Peterson, R. S..

13 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Development and flight evaluation of an augmented stability active controls concept with a small horizontal tail

A limited authority pitch active control system (PACS) was developed for a wide body jet transport (L-1011) with a flying horizontal stabilizer. Two dual channel digital computers and the associated software provide command signals to a dual channel series servo which controls the stabilizer power actuators. Input sensor signals to the computer are pitch rate, column-trim position, and dynamic pressure. Control laws are given for the PACS and the system architecture is defined. The piloted flight simulation and vehicle system simulation tests performed to verify control laws and system operation prior to installation on the aircraft are discussed. Modifications to the basic aircraft are described. Flying qualities of the aircraft with the PACS on and off were evaluated. Handling qualities for cruise and high speed flight conditions with the c.g. at 39% mac ( + 1% stability margin) and PACS operating were judged to be as good as the handling qualities with the c.g. at 25% (+15% stability margin) and PACS off.

Rising, J. J.↗
NASA NTRS1977

Production of soft X-ray emitting slow multiply charged ions - Recoil ion spectroscopy

S ions with a mean charge state of about 14+ and Cl ions with a mean charge state of 12+ were used to study Ne L-shell vacancy production. The ions caused copious production of NeII-NeVIII excited states with approximately 10 to the minus 18 sq cm cross sections. The induced recoil velocities might have application to a significantly higher resolution spectroscopy than is possible with beam-foil methods.

Sellin, I. A.↗
NASA NTRS1976

Radiative lifetimes and transition probabilities for electric-dipole delta n equals zero transitions in highly stripped sulfur ions

The beam-foil time-of-flight method has been used to investigate radiative lifetimes and transition rates involving allowed intrashell transitions within the L shell of highly ionized sulfur. The results for these transitions, which can be particularly correlation-sensitive, are compared with current calculations based upon multiconfigurational models.

Pegg, D. J.↗
NASA NTRS1976

Differences in the production of noncharacteristic radiation in gaseous and solid targets

Bell et al. (1975) found that the observed yield of noncharacteristic radiation (NCR) for a beam of S atoms hitting Al and Ne targets is of approximately equal magnitude for gaseous and solid targets under similar collision conditions. They concluded that NCR is produced predominantly in single collisions for 55-MeV S atoms on an Al target. This conclusion is tested in a similar collision system by comparing the NCR yields obtained with a 40-MeV Si(6+) ion beam on SiH4 (gaseous target) and on Al (solid target). Corrected X-ray spectra recorded in both cases clearly indicate a difference in the NCR yield for gaseous and solid targets. The results suggest that double collisions dominate the NCR production and that a single-collision production contribution of 15% to 20% is an upper limit for the projectile-target system used.

Laubert, R.↗
NASA NTRS1974

Characterization of charge states of energetic ions in solids from associated K X-ray production

The strong projectile-charge-state dependence of K X-ray production in gases establishes a charge-state scale for ions penetrating solids. Si K X-ray cross sections in gaseous SiH4 were compared to those in solid Si for 40-MeV O (6+ to 8+) and 86-MeV Ar (6+ to 16+) projectiles. For Ar an effective charge of 11 plus or minus one is found compared to an emergent charge of 14.8 plus or minus 0.5. The result is discussed in terms of alternate models for steady-state excitation in solids.

Datz, S.↗
NASA NTRS1974

Extreme ultraviolet spectra of highly ionized oxygen and fluorine

The foil-excitation method has been used to study the extreme ultraviolet spectra of highly ionized oxygen and fluorine. Several previously unreported lines in heliumlike fluorine are reported and other newly reported lines in heliumlike oxygen have been measured to higher accuracy. Included in the measurements are certain heliumlike oxygen transitions of significance in interpretation of solar-flare spectral observations. The wavelength determinations are usually in good agreement with calculated results which includes relativistic corrections, but discrepancies arise when nonrelativistic calculations are used. A comparison of the present results and those recently obtained by theta-pinch and laser-induced plasma sources is made for both heliumlike and lithiumlike ions; a few discrepancies occur, with results in most cases in better agreement with relativistically corrected calculations. Certain unidentified lines in the spectra may be attributable to radiative transitions between quartet states of lithiumlike ions.

Pegg, D. J.↗