Thermoelectric-generator testing and RTG degradation-mechanisms evaluation. Progress report No. 32

Thermal conductivity tests of the older p-type were terminated after 22,000 hours. The n-type selenide legs after 8000 hours continue to show agreement with the 3M Co. published data. In the ingradient testing after 10,200 hours the n-legs show comparable performance to the reported 3M data. A new station for ingradient performance testing of the new design p-type legs with the Astroquartz/slurry wrap was nearly completed. Weight loss testing of the new design p-type TPM217 (no partition) with the Astroquartz/slurry wrap has been discontinued. A check of the last sample after 2649 hours at T/sub H/9000C and T/sub C/1500C shows a low weight loss rate, but the hot cap popped off during tests. Three 18 couple modules s/n-1,2, and 3 previously tested at RCA were received for JPL test and evaluation. S/n-1 was put on test. Testing of the ring converter was terminated after 40,939 hours. The remaining MHW generator, Q1-A, on test has accumulated 16,924 hours and performance remains stable. The performance of the Voyager 1 and 2 RTGs is reported after 17,897 hours and 18,448 hours of operation, respectively