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Hayes, J. R.

Publications and source records attributed to Hayes, J. R..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

High-field transport properties of InAs(x)P(1-x)/InP (x = 0.3-1.0) modulation doped heterostructures at 300 and 77 K

Detailed measurements at 300 and 77 K have been made of the high-field transport properties of pseudomorphic InAsP/InP modulation-doped heterostructures grown by low-pressure organometallic CVD. The high-field channel velocities are comparable to or better than that of InGaAs/InAlAs heterostructures, and the transport properties of InAs/InP heterostucture suggest that carriers remain confined in the channel even at high fields.

Yang, D.↗
NASA NTRS1991

Experience with custom processors in space flight applications

The Applied Physics Laboratory (APL) has developed a magnetometer instrument for a swedish satellite named Freja with launch scheduled for August 1992 on a Chinese Long March rocket. The magnetometer controller utilized a custom microprocessor designed at APL with the Genesil silicon compiler. The processor evolved from our experience with an older bit-slice design and two prior single chip efforts. The architecture of our microprocessor greatly lowered software development costs because it was optimized to provide an interactive and extensible programming environment hosted by the target hardware. Radiation tolerance of the microprocessor was also tested and was adequate for Freja's mission -- 20 kRad(Si) total dose and very infrequent latch-up and single event upset events.

Fraeman, M. E.↗
NASA NTRS1990

An innovative on-board processor for lightsats

The Applied Physics Laboratory (APL) has developed a flightworthy custom microprocessor that increases capability and reduces development costs of lightsat science instruments. This device, called the FRISC (FORTH Reduced Instruction Set Computer), directly executes the high-level language called FORTH, which is ideally suited to the multitasking control and data processing environment of a spaceborne instrument processor. The FRISC will be flown as the onboard processor in the Magnetic Field Experiment on the Freja satllite. APL has achieved a significant increase in onboard processing capability with no increase in cost when compared to the magnetometer instrument on Freja's predecessor, the Viking satellite.

Henshaw, R. M.↗