"An investigation of the low-speed, power-off stability and control characteristics of a 1/10-scale model simulating the Convair F-102A airplane has been made in the Langley free-flight tunnel. The model in its basic configuration and with two modifications involving leading- edge slats and an increase in vertical-tail size was flown through a lift-coefficient range from 0.7 to the stall. Only relatively low-altitude conditions were simulated" (p. 1).

Report presenting ignition-delay determinations of furfuryl alcohol and mixed butyl mercaptans with various white fuming nitric acids were made at several temperatures with a modified open-cup apparatus and a small-scale rocket engine of approximately 30-pounds thrust.

Report presenting an investigation to determine the effects on internal performance of several geometric variables intended to produce a short, high-performance convergent-divergent nozzle. Some of the characteristics investigated included variations in the throat-contour radius, combinations of the shape of the convergent section and throat-contour radius, divergence angle, and shape of the divergent section.

Report presenting an investigation at Mach numbers 1.9 and 3.0 to demonstrate that a central core of air of high stagnation temperature can be produced in the test section of a supersonic wind tunnel. This makes performing wind tunnel testing cheaper and controls for more variables. Results regarding the core studies at Mach number 1.9 and 3.0 and diffuser performance at Mach number 1.9 are provided.

Report presenting an investigation performed at Mach number 2.96 to study the effects of some internal boundary-layer-control systems on the pressure recovery and stability characteristics of a side inlet with half a double-shock external compression surface. Counterbody bleed did not appreciably improve the performance of the inlet, and the maximum pressure recovery obtained was 62 percent. Results regarding the inlet performance with internal bleed and inlet performance with flow injection on external compression surface are provided.

Report presenting an experimental investigation of a series of fixed-geometry exhaust nozzles which simulated a variable exit, which was conducted in the 8- by 6-foot supersonic wind tunnel at Mach numbers 0, 0.6, 1.5, 1.7, and 2.0. Gross thrust performance of the long-shroud exit configurations was considerably better than the short-shroud. Results regarding flow coefficients, thrust characteristics, flight performance analysis of data, and shroud drag are provided.

From Summary: "The exhaust of a 6-inch-diameter ram-jet engine mounted in the Lewis 1- by 1-foot, Mach 3.1 supersonic tunnel was scavenged successfully with a 6.6-inch-diameter scoop. Limiting values of exhaust-to-stream static-pressure ratios and scavenge-system total-pressure ratios were determined for complete scavenging of the products of combustion. The scavenge-system operation influenced the engine exhaust-nozzle pressures under conditions of unstable scavenge flow."

Abstract: "The self-consistent equations have been found for a plasma which lies in a mainly unidirectional magnetic field, which has a circular symmetry and which has a harmonic variation in the direction of the magnetic field. The equations have been solved in two cases, 1) where the harmonic variation of the field is finite and the plasma is weak, and 2) where the plasma is strong but the harmonic variation of the field is weak. The configurations thus found can form an important starting point for calculations of the stability of plasmas."

In connection with the development of in-line analytical equipment for monitoring pH, gamma activity and uranium concentration in process streams, experiments and tests were carried out during the past year and a half in the Metal recovery Plant on a pH monitor for the hydrogen ion concentration in neutralized waste, a continuous gamma activity monitor on the RCU, an automatic photometer for uranium in RAF, and an automatic polarograph for uranium in RAW. This letter is written to present up-to-date diagrams of the equipment used, outline briefly the studies conducted and the main conclusions regarding design and operability of the equipment, and present material which will supplement that included in the previous reports on theses instruments.

The Spectroscopy Research Laboratory is concerned with research and development in the fields of nuclear magnetic resonance, microwaves, infrared and optical spectroscopy, spectrochemistry, and x rays. Research is directed toward fruitful methods of isotope analysis; new element and compound analytical methods having application to immediate Laboratory or long-range commission needs; and fundamental research on isotopes, elements, and compounds. The work is reported on a project basis to give a more complete picture of the purpose, activity, and status of each program. More detailed information on reported or inactive projects may be obtained from the previous semiannual report.