Determining Ionizing Doses in Medium Earth Orbits Using Long-Term GPS Particle Measurements

Total Ionizing Dose and Synergistic Effect of Magnetoresistive Random Access Memory

Magetoresistive Random Access Memory (MRAM) was irradiated by 60Co γ-rays and electron beam. The test of synergistic effect was performed under additional magnetic field when irradiation. We analyzed Total Ionizing Dose (TID) and synergistic damage mechanism of MRAM. DC, AC and function parameters of the memory were tested in radiation and annealing by Very Large Scale Integrated circuit (VLSI) test system. The radiation sensitive parameters were obtained through analyzing the data. Because magnetic field imposed on MRAM when the test of synergistic effect, Shallow Trench Isolation (STI) leaka…

利用 LabOSat-01 对低地球轨道小卫星进行总电离剂量测量

Total Ionizing Dose Measurements in Small Satellites in LEO using LabOSat-01

本文利用 LabOSat-01 平台搭载 p-MOSFET 商用器件，在两次累计 1100 天的低地球轨道小卫星任务中测量总电离剂量，测得不同屏蔽位置下 TID 为 5–19 Gy。

Radiation Analysis for Moon and Mars Missions

This paper provides an overview of the radiation aspects of manned space flight to Moon and Mars. The expected ionizing radiation dose for an astronaut is assessed along the Apollo 11 flight path to the Moon. With the two dose values, the expected and the measured total dose, the radiation shielding and the activity of the Sun are estimated. To judge the risk or safety margin the radiation effects on humans are opposed. The radiation from the Sun has to be set to zero in the computer model to achieve the published radiation dose value of the Apollo 11 flight. Galactic and cosmic particles have…

A link between solar events and congenital malformations: Is ionizing radiation enough to explain it?

Cosmic rays are known to cause biological effects directly and through ionizing radiation produced by their secondaries. These effects have been detected in airline crews and other specific cases where members of the population are exposed to above average secondary fluxes. Recent work has found a correlation between solar particle events and congenital malformations. In this work we use the results of computational simulations to approximate the ionizing radiation from such events as well as longer term increases in cosmic ray flux. We find that the amounts of ionizing radiation produced by t…

Strong Proton-Defect Interaction in Synergistic Irradiation Damage System

We experimentally investigated total ionizing dose (TID) response of the input-stage PNP transitor in an operational amplifier LM324N with various initial displacement damage (IDD). We found that, the damage first decreases and then increases with the total dose, which can be exactly described by a dose-rate-dependent linear generation term, an IDD-dependent linear annealing term, and a dose-rate-dependent exponential annealing term. We demonstrate that, the first two terms are the well-known TID and injection annealing effect, respectively, while the third term stems from the reactions betwee…

Determination of the Stopping Power and Failure-time of Spacecraft Components due to Proton Interaction Using GOES 11 Acquisition Data

One of the several ways to describe the net effect of charged-particles' interaction is the rate of energy loss along the particles' path. In this study, the mass stopping power (Sp) of selected spacecraft composite materials, through which the particle traverses, its range (R) and the distance (d) travelled (by the particles) through the materials have been calculated and analyzed. The dose (in Gy) as a function of particle flux and deposited energy was also determined. Predictions of their possible effects on space system operations and life-span were made, especially as values exceeded cert…