Ceramic photon counters

[J.F.I.

CURRENT TOPICS

532 machine refractory metals, interplanetary space probes. Nonfading

Radio

and

track

Reception.-

An experimental radio communication system using 28-foot dish antennas to send and receive a message over several angularly separated radio beams simultaneously to help assure nonfading reception has been developed under Air Force contract by ITT Federal Laboratories Division of International Telephone and Telegraph Corporation. Seven separate feed horns driven by seven individual transmitters bounce the same message off the 28-ft. diameter parabolic reflector and into space. As a result, seven separate beams are formed in space. The power scattered within the atmosphere is picked up by a receiving system, consisting of two parabolic antennas each with seven feed horns similar to the transmitting system. Late-model low-noise parametric amplifier receiving systems drive various and recording computing equipment which compiles statistics on the 14 received signals. This information is registered on data cards for analysis and data processing. The experiment will permit simultaneous comparison of multiple-angle diversity with other forms of diversity such as space and frequency diversity. Advantages of the angle-diversity arrangement are that diversity improvement is attained by a single receiving antenna using multiple beams instead of a receiving system requiring either more antennas or a wide radio spectrum or both. Ceramic

Photon

Counters.-A

new series of ceramic photon counters, optical instruments which measure the intensity and variability of ultraviolet radiation in narrow bands of the solar spectrum, is being offered by the Geophysics Corporation of America for in-

clusion in rocket and satellite space probes, or for use in laboratoiy research. The basic design for the small devices was developed at the National Aeronautics and Space Administration Goddard Space Flight Center. Aboard a rocket or satellite the instruments can be used to measure Lyman alpha radiation and other portions of the solar spectrum which do not penetrate to the earth’s surface. In the laboratory, in conjunction with a light source able to simulate these wavelengths, the counters may be used to perform absorption studies of gases or to determine the reflectivity of metals. Measurements may be performed in such narrow spectrum bands as 10501180 angstroms, 1050-1250A, 10501350A, and 1225-1350A. Counters are filled with a variety of gases and are equipped with a variety of crystal windows depending upon the experiment. Exhaust and filling tubulation is provided with either metal or glass pinch-offs for mounting on a vacuum system. The instruments can be calibrated for absolute photon flux measurement, can be operated under gas amplification conditions, and may be used in combinations of two units to perform studies of other spectral regions. External dimensions are: main body, 1.000 in.; mounting flange diameter, 1.365 in.; length, 1.490 in.; window aperture diameter, 0.375 in. Computer ing.-Engineers

Tire

Design

and Test-

at The University of Michigan have developed a way to build a tire, inflate it and test it-all on a digital computer without using any real tire material. Their achievement is significant because for the first time it will allow tire designers to get around traditional trial and error methods and begin to engineer a tire directly to vehicle specifications. The project