Solid State Radiation Dosimeters for Space and Medical Applications

This report describes the development of two radiation monitors (RADMON's) for use in detecting total radiation dose and high-energy particles. These radiation detectors are chip-size devices fabricated in 1.2 micrometer CMOS and have flown in space on both experimental and commercial spacecraft. They have been used to characterize protons and electrons in the Earth's radiation belts, particles from the Sun, and protons used for medical therapy. Having proven useful in a variety of applications, the detector is now being readied for commercialization

Measurement and analysis of soft error vulnerability of low-voltage logic and memory circuits

Scaling the supply voltage into the sub/near-threshold domain is one of the most effective methods for improving the energy efficiency of next-generation electronic microsystems. Unfortunately, the relationship between low-voltage operation and radiation-induced soft error rate is not widely known, as little research has been previously performed and reported for soft-error susceptibility of on-chip memory and logic at very low supply voltages. This information is critical for low-voltage circuit designers, as many applications that would benefit from the energy effi­ciency of sub/near-threshold also require high reliability. This work first details the design and implementation of a portable soft error reference platform, specif­ically targeting very low-voltage operation. The circuit-level details of a TSMC 65nm test-chip design are given, along with an analysis of data from experiments performed at Los Alamos Neutron Science Center (LANSCE) and the OSU Radi­ation Center. Once this soft-error rate is known, error resiliency techniques must be utilized for increased processor reliability. The design and implementation of an error-resilient, near-threshold SIMD processor in an IBM 45nm SOI process will also be covered. This prototype demonstrates both increased reliability and improved throughput over a conventional SIMD pipeline while operating in near-threshold

Assessing the performance of Digital Micromirror Devices for use in space-based multi-object spectrometers

A current need in space-based instrumentation is a reconfigurable slit mask. Several techniques for slit masks have been employed for ground-based astronomical spectrographs. These ground-based instruments have used large discrete components, which are impractical for remote operation in space-based deployment. The Texas Instruments\u27 Digital Micromirror Device (DMD) was originally conceived purely for display purposes, but is a viable candidate to be use as a slit mask in a space-based multi-object spectrograph (MOS). The Integrated Circuit (IC) manufacturing industry has enabled the robust integration of both silicon transistors and Micro-Electrical Mechanical Systems (MEMS) optical components into a very reliable monolithic chip (the DMD). The focus of this work was in three areas that addressed the suitability of proposing DMDs for future space missions. The DMDs were optically characterized to assess their utility in a spectrograph. The DMDs were also cooled in a liquid nitrogen dewar to determine their minimum operating temperature. The low temperature tests indicated that the DMD can operate to temperatures as low as 130 K. In addition, several DMDs were irradiated with high-energy protons at the LBNL 88 Cyclotron to determine how robust the devices are to ionizing radiation (protons). The radiation testing results indicate that DMDs would survive medium to long duration space missions with full operability. Based on preliminary tests in these three areas, the DMD should be considered as an excellent candidate for deployment in future space missions

Evaluating the performance of digital micromirror devices for use as programmable slit masks in multi-object spectrometers

Multi-object spectrometers are extremely useful astronomical instruments that allow simultaneous spectral observations of large numbers of objects. Studies performed with ground-based multi-object spectrometers (MOSs) in the last four decades helped to place unique constraints on cosmology, large scale structure, galaxy evolution, Galactic structure, and contributed to countless other scientific advances. However, terrestrial MOSs use large discrete components for object selection, which, aside from not transferable to space-based applications, are limited in both minimal slit width and minimal time required accommodate a change of the locations of objects of interest in the field of view. There is a pressing need in remotely addressable and fast-re-configurable slit masks, which would allow for a new class of instruments - spacebased MOS. There are Microelectromechanical System (MEMS) - based technologies under development for use in space-based instrumentation, but currently they are still unreliable, even on the ground. A digital micromirror device (DMD) is a highly capable, extremely reliable, and remotely re-configurable spatial light modulator (SLM) that was originally developed by Texas Instruments Incorporated for projection systems. It is a viable and very promising candidate to serve as slit mask for both terrestrial and space-based MOSs. This work focused on assessing the suitability of DMDs for use as slit masks in space-based astronomical MOSs and developing the necessary calibration procedures and algorithms. Radiation testing to the levels of orbit around the second Lagrangian point (L2) was performed using the accelerated heavy-ion irradiation approach. The DMDs were found to be extremely reliable in such radiation environment, the devices did not experience hard failures and there was no permanent damage. Expected single-event upset (SEU) rate was determined to be about 5.6 micro-mirrors per 24 hours on-orbit for 1-megapixel device. Results of vibration and mechanical shock testing performed according to the National Aeronautics and Space Administration (NASA) General Environmental Verification Standard (GEVS) at NASA Goddard Space Flight Center (GSFC) suggest that commercially available DMDs are mechanically suitable for space-deployment with a very significant safety margin. Series of tests to assess the performance and the behaviour of DMDs in cryogenic temperatures (down to 78 K) were also carried out. There were no failures or malfunctions detected in commercially-available devices. An earlier prototype of a terrestrial DMD-based MOS (Rochester Institute of Technology Multi-Object Spectrometer (RITMOS)) was updated with a newer DMD model, and the performance of the instrument was evaluated. All the experiments performed strongly suggest that DMDs are highly reliable and capable devices that are extremely suitable for use as remotely programmable slit masks in MOS

NASA Space Engineering Research Center Symposium on VLSI Design

The NASA Space Engineering Research Center (SERC) is proud to offer, at its second symposium on VLSI design, presentations by an outstanding set of individuals from national laboratories and the electronics industry. These featured speakers share insights into next generation advances that will serve as a basis for future VLSI design. Questions of reliability in the space environment along with new directions in CAD and design are addressed by the featured speakers

The development of an active area neutron dosemeter

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Technology 2001: The Second National Technology Transfer Conference and Exposition, volume 1

Papers from the technical sessions of the Technology 2001 Conference and Exposition are presented. The technical sessions featured discussions of advanced manufacturing, artificial intelligence, biotechnology, computer graphics and simulation, communications, data and information management, electronics, electro-optics, environmental technology, life sciences, materials science, medical advances, robotics, software engineering, and test and measurement

Large space structures and systems in the space station era: A bibliography with indexes (supplement 04)

Bibliographies and abstracts are listed for 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system between 1 Jul. and 30 Dec. 1991. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems