The radiation risk assessment for long-term space missions requires knowledge on the biological effectiveness of different space radiation components, e.g. heavy ions, on the interaction of radiation and other space environmental factors such as microgravity, and on the physical and biological dose distribution in the human body. Space experiments and ground-based experiments at heavy ion accel...

The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demo...

A summary is provided of presentations and discussions at the NASA Radiation Biomarker Workshop held September 27-28, 2007 at NASA Ames Research Center in Mountain View, CA. Invited speakers were distinguished scientists representing key sectors of the radiation research community. Speakers addressed recent developments in the biomarker and biotechnology fields that may provide new opportunitie...

Citation Duan, Zhaoyun et al. " Novel Electromagnetic Radiation in a Semi-infinite Space Filled with a Double-negative Metamaterial. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. We have theoretically investigated the electromagnetic radiation excited by a charged particle moving along a semi-infinite space filled with a d...

INTRODUCTION For future space missions at the International Space Station, health risk to astronauts caused by space radiation needs to be properly quantified and controlled. The radiation field in space is low-dose rate, but the accumulated dose can be high during long-term missions (1). Radiological risk under such a low dose-rate exposure, i.e. stochastic effect, has generally been evaluated...

This Letter describes a scalar curvature invariant for general relativity with a certain, distinctive feature. While many such invariants exist, this one vanishes in regions of space-time which can be said unambiguously to contain no gravitational radiation. In more general regions which incontrovertibly support nontrivial radiation fields, it can be used to extract local, coordinate-independen...

This report contains the notes from the second session of the 1997 IEEE Nuclear and Space Radiation Effects Conference Short Course on Applying Computer Simulation Tools to Radiation Effects Problems. Part A discusses the physical phenomena modeled in radiation transport codes and various types of algorithmic implementations. Part B gives examples of how these codes can be used to design experi...

approved: _____________________________________________________ Un-Ku Moon Kartikeya Mayaram Circuits operating outside the earth’s atmosphere are more vulnerable to cosmic radiation and require special design consideration. The purpose of this work is to explore methods of mitigating the effect of radiation in phase locked loop (PLL) circuits. Several voltage controlled oscillators (VCOs) and ...

Titanium alloys have found numerous applications in space research, and nuclear industry and research. Since X-rays constitute an important part of the space radiation environment, numerical simulations of radiation absorption characteristics of titanium alloys were studied in this paper. The photon transport Monte Carlo software was used for determining the energy deposited in titanium samples...