Shielding Effectiveness of a Spacecraft Faraday Cage With Pin 1 Connections
Estimates are made of the shielding effectiveness (SE) of a satellite Faraday cage with Pin 1 connections. Degradation of the SE by space radiation and solar-thermal cycling is described. The impact of multilayer insulation on the SE is assessed.
Physical and Spectrometric Analysis of Electron-Damaged LDPE
Low-density polyethylene (LDPE) is a nonpolar polymer commonly used as an insulating material. Although its applications in the spacecraft industry are limited, LDPE is widely utilized as a model system to study electron transport through disordered insulating materials under simulated space weather conditions. The charge transport models developed using this system may then be extended to more commonly used spacecraft materials such as polyimides. Several proposed charge transport models share high complexity and many free fitting parameters. For better estimation of initial values of these free parameters, the correlation between charge transport and its chemical origins should be made. Whenever possible, experimental measurements should be used as initial values for each of the free fitting parameters to improve model accuracy. In this paper, we studied alterations of the chemical properties of LDPE after irradiation by high-energy (100 keV) electrons using Fourier transform infrared spectroscopy (FTIR) and bulk conductivity measurements. Moreover, we utilized a quadrupole mass spectrometer (QMS) to identify the ablated species released from the solid during irradiation. These measurements offer insight into the structural and chemical damages of the material. Results of the performed analysis are correlated with the underlying chemical changes that occur in LDPE during irradiation.
RIP - General Purpose Interactive Display at HHIRF
RIP is a general purpose interactive code for display and analysis of data acquired with the Holifield Heavy Ion Research Facility (HHIRF) accelerators at Oak Ridge National Laboratory. The HHIRF data acquisition system includes a version of RIP for on-line display of one-and two-dimensional histograms on color graphic terminals and hard copy on color printer/plotters. General features of the program and interactive techniques will be described.