1 Recent Radiation Test Results at JPL
This Bruce E. Pritchard, Member, ZEEE, Bemard G. Rax, and Steven S. McClure paper documents recent TID (including ELDRS) and proton damage test results obtained by JPL. Unusual test results, such as abnormally low or high failure levels or unusual failure or response mechanism, are emphasized.
Total ionizing dose (TID) evaluation results of low dose rate testing for NASA programs
Low dose rate radiation testing in the range of 0.01-0.20 rads(Si)/s has been performed at Goddard Space Flight Center on a wide variety of non-RH (rad-hard) part types in the last few years. This paper reports on recent test results of EEPROMs, Operational Amplifiers, Analog-to-Digital Converters (ADCs) and Digital-to-Analog Converters (DACs), and DC-DC converters. These results have shown that non-RH parts are suitable for many low earth orbiting satellites, where predicted mission total dose requirements may be in the range of 0.5-10 krads(Si). However, a careful characterization of non-RH parts should be performed to verify that the parts meet the requirements of their intended application in the projected mission radiation environment.
Determination of Optimal Ball-Burnishing Parameters for Plastic Injection Moulding Steel
The objective of this study is to determine the optimal plane ball-burnishing parameters for plastic injection moulding steel PDS5 on a machining centre by utilising the Taguchi’s orthogonal array method. The design and manufacture of a burnishing tool are described. Four burnishing parameters, namely the ball material, burnishing speed, burnishing force and feed, were selected as the experimental factors in Taguchi’s design of experiments to determine the optimal burnishing parameters which have the dominant influence on surface roughness. The optimal burnishing parameters were found after carrying out the experiments specified by Taguchi’s L18 orthogonal table, by the analysis of variation, and by a full factorial experiment. The optimal plane burnishing parameters for the plastic injection moulding steel PDS5 were a combination of a tungsten carbide ball, a burnishing speed of 200 mm/min, a burnishing force of 300 N and a feed of 40 μm. The surface roughness Ra of the specimen can be improved from about 1 μm to 0.07 μm by using the optimal burnishing parameters for plane burnishing.