A high performance guidance system for sounding rockets

1986 ◽  
Author(s):  
R. BAILEY
Keyword(s):  
High Performance ◽  
Guidance System ◽  
Sounding Rockets

Transpiration Cooled Porous Type Vi Silica Rocket Windows

1990 ◽  
Vol 180 ◽  
Author(s):  
Albert G Fosmoe II ◽  
Larry L. Hench
Keyword(s):  
Nitric Acid ◽  
High Performance ◽  
Sol Gel ◽  
Guidance System ◽  
Transpiration Cooling ◽  
Average Pore ◽  
Optically Transparent ◽  
Cooling Effects ◽  
Acid Catalyzed

ABSTRACTA novel use of sol-gel derived porous Type VI silica for high performance rocket guidance system windows is evaluated. The samples produced for this study were optically transparent hydrofluoric and/or nitric acid catalyzed tetramethylorthosilicate (TMOS) xerogel monoliths with average pore radii of 1.2, 5.0, and 8.Onm. Maximum He transpiration velocities of up to 3 cm/sec, 3 times the velocity needed for transpiration cooling, are measured for a 5.0 nm sample at 3.2 MPa. Transpiration velocities of 0.6 cm/sec result in cooling effects as large as 44°C from 160°C.

Critical Gas Bearing Slew Test Evaluation With a Varmeter

1970 ◽  
Vol 92 (3) ◽  
pp. 509-517
Author(s):  
A. J. Lynch ◽  
P. Steranka
Keyword(s):  
High Performance ◽  
Guidance System ◽  
Performance Criteria ◽  
Test Evaluation ◽  
Weight Restrictions ◽  
Support Area ◽  
Guidance Systems ◽  
Gas Bearing

In the Pendulous Integrating Gyro Accelerometer (PIGA) used in inertial guidance systems, the gas bearing wheel is operated in a slewing mode at high slew rates. The high performance criteria of the guidance system require that the gas bearing operate without degradation and without loss of synchronous spin velocity at high slew rates. Size and weight restrictions limit the available support area, requiring that the gas bearing be operated near its maximum capability under high slew rates. An MIT-designed varmeter has been a proven tool to critically evaluate gas bearing performance under high slew rates. The varmeter is sensitive to slightest contact between the rotating member and a stationary member and can detect the slightest loss of synchronous speed.

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

1970 ◽  
Vol 28 ◽  
pp. 360-361
Author(s):  
John W. Coleman
Keyword(s):  
Boundary Conditions ◽  
High Performance ◽  
Force Fields ◽  
Optical Design ◽  
Direct Conversion ◽  
Design Engineering ◽  
Design Data ◽  
Scalar Potentials ◽  
Geometric Elements ◽  
At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

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