P.R. Boberg

Bio: P.R. Boberg is an academic researcher. The author has contributed to research in topics: Cosmic ray & Single event upset. The author has an hindex of 3, co-authored 3 publications receiving 654 citations.

CREME96: A Revision of the Cosmic Ray Effects on Micro-Electronics Code

Abstract: CREME96 is an update of the Cosmic Ray on Micro-Electronics code, a widely-used suite of programs for creating numerical models of the ionizing-radiation environment in near-Earth orbits and for evaluating radiation effects in spacecraft. CREME96, which is now available over the World-Wide Web (WWW) at http://crsp3.nrl.navy.mil/creme96/, has many significant features, including: (1) improved models of the galactic cosmic ray, anomalous cosmic ray, and solar energetic particle ("flare") components of the near-Earth environment; (2) improved geomagnetic transmission calculations; (3) improved nuclear transport routines; (4) improved single-event upset (SEU) calculation techniques, for both proton-induced and direct-ionization-induced SEUs; and (5) an easy-to-use graphical interface, with extensive on-line tutorial information. In this paper we document some of these improvements.

Single event upsets caused by solar energetic heavy ions

Abstract: We calculate single event upset (SEU) rates due to protons, alphas, and heavier ions in two satellite systems for the major solar particle events of 1989-92, using a new and complete analysis of GOES proton data and high-energy heavy-ion fluences from the University of Chicago Cosmic Ray Telescope on IMP-8. These measurements cover the entire range of energies relevant to SEU studies and therefore overcome shortcomings of previous studies, which relied upon theoretical or semi-empirical estimates of high-energy heavy-ion spectra. We compare our results to the observed SEU rates in these events. The SEU rates in one device (AMD 93L422s on LEASATs) were overwhelmingly dominated by protons. However, even after taking into account uncertainties in the ground-test cross-section data, we find that at least /spl sim/45% of the SEUs in the other device (Fairchild 93L422s on TDRS-1) must have been caused by heavy ions. Our results demonstrate that both protons and heavy ions must be considered in order to make a reliable assessment of SEU vulnerabilities. Furthermore, the GOES/Chicago database of solar particle events provides a basis for making accurate solar particle SEU calculations and credible worst-case estimates. In particular, measurements of the historic solar particle events of October 1989 are used in "worst week" and "worst day" environment models in CREME96, a revision of NRL's Cosmic Ray Effects on MicroElectronics code.

CREME96: A Revision of the Cosmic Ray Effects on Micro-Electronics Code

Abstract: CREME96 is an update of the Cosmic Ray on Micro-Electronics code, a widely-used suite of programs for creating numerical models of the ionizing-radiation environment in near-Earth orbits and for evaluating radiation effects in spacecraft. CREME96, which is now available over the World-Wide Web (WWW) at http://crsp3.nrl.navy.mil/creme96/, has many significant features, including: (1) improved models of the galactic cosmic ray, anomalous cosmic ray, and solar energetic particle ("flare") components of the near-Earth environment; (2) improved geomagnetic transmission calculations; (3) improved nuclear transport routines; (4) improved single-event upset (SEU) calculation techniques, for both proton-induced and direct-ionization-induced SEUs; and (5) an easy-to-use graphical interface, with extensive on-line tutorial information. In this paper we document some of these improvements.

A framework for information quality assessment

Abstract: One cannot manage information quality (IQ) without first being able to measure it meaningfully and establishing a causal connection between the source of IQ change, the IQ problem types, the types of activities affected, and their implications. In this article we propose a general IQ assessment framework. In contrast to context-specific IQ assessment models, which usually focus on a few variables determined by local needs, our framework consists of comprehensive typologies of IQ problems, related activities, and a taxonomy of IQ dimensions organized in a systematic way based on sound theories and practices. The framework can be used as a knowledge resource and as a guide for developing IQ measurement models for many different settings. The framework was validated and refined by developing specific IQ measurement models for two large-scale collections of two large classes of information objects: Simple Dublin Core records and online encyclopedia articles. © 2007 Wiley Periodicals, Inc.

Physical basis of radiation protection in space travel

Abstract: The health risks of space radiation are arguably the most serious challenge to space exploration, possibly preventing these missions due to safety concerns or increasing their costs to amounts beyond what would be acceptable. Radiation in space is substantially different from Earth: high-energy ($E$) and charge ($Z$) particles (HZE) provide the main contribution to the equivalent dose in deep space, whereas $\ensuremath{\gamma}$ rays and low-energy $\ensuremath{\alpha}$ particles are major contributors on Earth. This difference causes a high uncertainty on the estimated radiation health risk (including cancer and noncancer effects), and makes protection extremely difficult. In fact, shielding is very difficult in space: the very high energy of the cosmic rays and the severe mass constraints in spaceflight represent a serious hindrance to effective shielding. Here the physical basis of space radiation protection is described, including the most recent achievements in space radiation transport codes and shielding approaches. Although deterministic and Monte Carlo transport codes can now describe well the interaction of cosmic rays with matter, more accurate double-differential nuclear cross sections are needed to improve the codes. Energy deposition in biological molecules and related effects should also be developed to achieve accurate risk models for long-term exploratory missions. Passive shielding can be effective for solar particle events; however, it is limited for galactic cosmic rays (GCR). Active shielding would have to overcome challenging technical hurdles to protect against GCR. Thus, improved risk assessment and genetic and biomedical approaches are a more likely solution to GCR radiation protection issues.

Space, atmospheric, and terrestrial radiation environments

Abstract: The progress on developing models of the radiation environment since the 1960s is reviewed with emphasis on models that can be applied to predicting the performance of microelectronics used in spacecraft and instruments. Space, atmospheric, and ground environments are included. It is shown that models must be adapted continually to account for increased understanding of the dynamics of the radiation environment and the changes in microelectronics technology. The IEEE Nuclear and Space Radiation Effects Conference is a vital forum to report model progress to the radiation effects research community.

Monte Carlo Simulation of Single Event Effects

Abstract: In this paper, we describe a Monte Carlo approach for estimating the frequency and character of single event effects based on a combination of physical modeling of discrete radiation events, device simulations to estimate charge transport and collection, and circuit simulations to determine the effect of the collected charge. A mathematical analysis of the procedure reveals it to be closely related to the rectangular parallelepiped (RPP) rate prediction method. The results of these simulations show that event-to-event variation may have a significant impact when predicting the single-event rate in advanced spacecraft electronics. Specific criteria for supplementing established RPP-based single event analysis with Monte Carlo computations are discussed.