404:
335:
95:
17:
754:
Lee, Eun Kyung; Yin, Liang; Lee, Yongjin; Lee, Jong Woon; Lee, Sang Jin; Lee, Junho; Cha, Seung Nam; Whang, Dongmok; Hwang, Gyeong S.; Hippalgaonkar, Kedar; Majumdar, Arun; Yu, Choongho; Choi, Byoung Lyong; Kim, Jong Min; Kim, Kinam (13 June 2012). "Large
Thermoelectric Figure-of-Merits from SiGe
477:) with a cold junction temperature of 573 K (572 °F) compose the temperature gradient in the thermoelectric couple in the RTG. This mechanism provided the total electrical power to operate the spacecraft's instruments, communications and other power demands. The RTG on
354:
with phosphorus to provide thermoelectric polarity to the couple. The electrical and thermal currents of the system are separated by bonding the SiGe alloy thermocouple to a multifoil cold stack assembly of
86:
to fully meet the power demands of each spacecraft. The properties of the material and the remaining components of the RTG contribute towards the efficiency of this thermoelectric conversion.
1028:
Bennett, G.L; Lombardo, James; Hemler, Richard; Silverman, Gil; Whitmore C.; Amos, Wayne; Johnson, E.; Schock, Alfred; Zocher, Roy; Keenan, Thomas; Hagan, James; and
Richard Englehart.
411:
SiGe has been used as a material in RTGs since 1976. Each mission that has used RTG technology involves exploration of far-reaching regions of the solar system. The most recent mission,
265:. Thermoelectric power generation requires a constantly maintained temperature difference among the junctions of the two dissimilar metals (i.e. Si and Ge) to produce a low power
584:
481:
will produce adequate electrical power for spacecraft operation until about the year 2020. Similar MHW-RTG models are also used on the two U.S. Air Force communications
1032:, AIAA 2006-4096, 4th International Energy Conversion Engineering Conference and Exhibit (IECEC), 26–29 June 2006, San Diego, California (Accessed 10 February 2015)
673:
Böttner, H. (August 2002). "Thermoelectric micro devices: Current state, recent developments and future aspects for technological progress and applications".
469:
heat of the plutonium to electrical power was accomplished through 312 silicon-germanium (SiGe) thermoelectric couples. A hot junction temperature of 1273
862:
Xie, Ming; Gruen, Dieter M. (18 November 2010). "Potential Impact of ZT = 4 Thermoelectric
Materials on Solar Thermal Energy Conversion Technologies".
605:
281:
43:
690:
21:
630:
Tiwari, Pratibha; Gupta, Nishu; Gupta, K.M. (April 2013). "Advanced
Thermoelectric Materials in Electrical and Electronic Applications".
379:
the legs of the SiGe thermocouples. In between the inner insulation system and the outer shell, copper connectors form the electrical
968:
814:; Ren, Zhifeng (10 December 2008). "Enhanced Thermoelectric Figure-of-Merit in Nanostructured p-type Silicon Germanium Bulk Alloys".
1042:
1002:
Fleurial, Jean-Pierre; Caillat, Thierry; Nesmith, Bill J.; Ewell, Richard C.; Woerner, David F.; Carr, Gregory C.; Jones, Loren E.
806:
Joshi, Giri; Lee, Hohyun; Lan, Yucheng; Wang, Xiaowei; Zhu, Gaohua; Wang, Dezhi; Gould, Ryan W.; Cuff, Diana C.; Tang, Ming Y.;
726:
1062:
898:
1077:
487:
482:
175:
1082:
384:
1072:
1067:
610:
528:
155:
372:
392:
202:
575:
are expected to meet or exceed the remaining power performance requirements for their deep-space missions.
600:
376:
351:
347:
205:(e.g. SiGe alloys) as a supplemental source of power for missions near the Sun can operate unprotected in
137:
103:
154:
SiGe alloy devices are mechanically rugged and can withstand severe shock and vibration due to its high
727:"Optimization of Silicon-Germanium Thermoelectric Modules for Transportation Corps Silent Boat Design"
823:
811:
764:
639:
512:
507:
501:
380:
304:
298:
292:
71:
66:
60:
807:
474:
403:
788:
696:
655:
1003:
929:
Raag, V.; Berlin, R.E. (December 1968). "A silicon-germanium solar thermoelectric generator".
879:
839:
780:
686:
466:
319:
170:
equipment and bonds easily to construct components. SiGe alloy devices can operate under high
110:
27:
899:"High efficiency thermoelectric devices fabricated using quantum well confinement techniques"
651:
938:
871:
831:
772:
678:
647:
334:
266:
234:
210:
83:
1004:"Thermoelectrics: From Space Power Systems to Terrestrial Waste Heat Recovery Applications"
975:
556:
446:
364:
286:
226:
140:
133:
31:
1030:
Mission of Daring: The
General-Purpose Heat Source Radioisotope Thermoelectric Generator
827:
768:
643:
94:
588:
531:. The GPHS-RTG employs identical heat-to-electrical conversion technology used in the
388:
148:
129:
106:
1056:
942:
737:
700:
659:
470:
343:
167:
118:
792:
755:
Nanowires by
Simultaneously Measuring Electrical and Thermal Transport Properties".
563:. Based on performance, data and modeling for the SiGe alloy RTGs, the GPHS-RTGs on
213:. Such properties have made SiGe thermoelectrics convenient for power generation in
675:
Twenty-First
International Conference on Thermoelectrics, 2002. Proceedings ICT '02
519:
415:(2005), was originally set for a 3-year exploration, but was extended to 17 years.
310:
238:
171:
144:
78:
387:
design to connect the unicouples. The circuit loop arrangement minimizes the net
552:
262:
159:
434:
356:
277:
246:
218:
190:
174:(i.e. >1300 ˚C) without degradation due to their electronic stability, low
35:
682:
209:
and air environments under high temperatures due to their low sensitivity to
736:. TRECOM Technical Report 63-17. Accession Number: AD0412341. Archived from
430:
424:
270:
198:
179:
163:
82:
spacecraft. SiGe thermoelectric material converts enough radiated heat into
54:
48:
883:
843:
784:
591:(PbTe) thermocouples and Pu-238 dioxide for spacecraft power applications.
539:
missions, using SiGe thermocouples/unicouples and the Pu-238–fueled GPHS.
1029:
524:
360:
249:
act as the intermediary between the heat source and electrical assembly.
222:
532:
462:
450:
442:
438:
1013:. Jet Propulsion Laboratory/California Institute of Technology (2011).
875:
835:
776:
1043:"NASA's New Horizons Team Selects Potential Kuiper Belt Flyby Target"
458:
454:
368:
322:. The SiGe thermocouples/unicouples convert this heat to hundreds of
315:
230:
206:
125:
449:
fuel spheres for an operational life appropriate for exploration of
16:
560:
544:
402:
333:
242:
214:
93:
15:
323:
258:
194:
114:
39:
186:
233:, and alumina materials, provides the insulation between the
201:. However, thermoelectric energy conversion systems that use
34:
have been used for converting heat into electrical power in
548:
523:
on
January 19, 2006. All of these spacecraft contain the
974:. Nuclear News. American Nuclear Society. Archived from
583:
Missions after 2010 requiring RTGs will instead use the
969:"U.S. Space Missions Using Radioisotope Power Systems"
967:
Furlong, Richard R.; Wahlquist, Earl J. (April 1999).
276:
A large array of SiGe thermocouples/unicouples form a
551:). The spacecraft's next destination will be a small
346:
attached to the outer shell consist of a SiGe alloy
585:
multi-mission radioisotope thermoelectric generator
42:missions since 1976. This material is used in the
217:. The multifoil cold stack assembly, composed of
338:Conceptual diagram of a thermocouple (unicouple)
132:properties. Their performance in thermoelectric
495:General purpose heat source (GPHS) applications
437:launched in August and September 1977 required
121:or unicouples), are used in space exploration.
997:
995:
505:spacecraft launched on October 18, 1989, the
8:
371:, and alumina components. Several layers of
193:performance deteriorates from high incident
147:, which has been shown to be near 2 in some
962:
960:
958:
956:
954:
952:
720:
718:
716:
714:
712:
710:
559:that orbits nearly a billion miles beyond
924:
922:
280:that was incorporated into the design of
241:of the system. The SiGe n-leg doped with
1024:
1022:
1020:
897:Jurgensmeyer, Austin Lee (Summer 2011).
606:Advanced Stirling Radioisotope Generator
622:
483:Lincoln Experimental Satellites 8 and 9
857:
855:
853:
652:10.4028/www.scientific.net/AMR.685.161
282:radioisotope thermoelectric generators
117:) thermoelectric couples (also called
44:radioisotope thermoelectric generators
419:Multi-hundred-watt (MHW) applications
257:SiGe thermocouples in an RTG convert
22:radioisotope thermoelectric generator
7:
136:production is characterized by high
906:Colorado State University Libraries
864:The Journal of Physical Chemistry B
525:general purpose heat source (GPHS)
14:
547:and its moons on July 14, 2015 (
98:Components of the SiGe unicouple
549:see JHU Applied Physics website
375:silica fiber yarn electrically
330:Thermocouple/unicouple assembly
269:electric current without extra
20:Essential components of a SiGe
543:made its historic flyby past
407:RTG Space Exploration Timeline
1:
517:on October 15, 1997, and the
176:thermal expansion coefficient
943:10.1016/0013-7480(68)90033-8
734:Radio Corporation of America
284:(RTGs) used in the missions
158:(i.e. >7000 psi) and low
632:Advanced Materials Research
383:, which uses a two-string,
273:or external power sources.
197:and high temperatures from
1099:
245:and SiGe p-leg doped with
1011:U.S. Department of Energy
725:Dingwall, F. (May 1963).
611:Radioisotope heater units
529:U.S. Department of Energy
683:10.1109/ICT.2002.1190368
527:RTG commissioned by the
511:on October 6, 1990, the
344:thermocouples/unicouples
203:thermoelectric materials
38:designed for deep-space
808:Dresselhaus, Mildred S.
318:dioxide fuel undergoes
314:. On these spacecraft,
1063:Nuclear power in space
601:Thermoelectric cooling
555:object (KBO) known as
408:
385:series-parallel wiring
350:with boron and a SiGe
339:
99:
24:
1078:Spacecraft components
406:
337:
326:of electrical power.
97:
19:
677:. pp. 511–518.
465:. Conversion of the
1083:Inorganic chemistry
870:(45): 14339–14342.
828:2008NanoL...8.4670J
769:2012NanoL..12.2918L
644:2012AdMaR.443.1587Z
587:(MMRTG) containing
399:Application history
162:. SiGe material is
160:dislocation density
1073:Nuclear technology
439:multi-hundred-watt
409:
340:
100:
46:(RTGs) that power
25:
1068:Thermoelectricity
1045:. 28 August 2015.
931:Energy Conversion
876:10.1021/jp9117387
836:10.1021/nl8026795
822:(12): 4670–4674.
777:10.1021/nl300587u
743:on March 4, 2016.
692:978-0-7803-7683-0
445:) RTG containing
111:silicon-germanium
28:Silicon-germanium
1090:
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1046:
1039:
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1015:
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1008:
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989:
987:
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980:
973:
964:
947:
946:
926:
917:
916:
914:
912:
903:
894:
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859:
848:
847:
803:
797:
796:
763:(6): 2918–2923.
751:
745:
744:
742:
731:
722:
705:
704:
670:
664:
663:
627:
253:Power generation
239:thermal currents
211:radiation damage
156:tensile strength
143:(ZT) under high
141:figures-of-merit
84:electrical power
1098:
1097:
1093:
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724:
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708:
693:
672:
671:
667:
629:
628:
624:
619:
597:
581:
579:RTG alternative
557:486958 Arrokoth
497:
447:plutonium oxide
421:
401:
365:stainless steel
332:
255:
227:stainless steel
92:
32:thermoelectrics
12:
11:
5:
1096:
1094:
1086:
1085:
1080:
1075:
1070:
1065:
1055:
1054:
1049:
1048:
1034:
1016:
991:
948:
937:(4): 161–168.
918:
889:
849:
798:
746:
706:
691:
665:
621:
620:
618:
615:
614:
613:
608:
603:
596:
593:
589:lead telluride
580:
577:
496:
493:
420:
417:
400:
397:
389:magnetic field
331:
328:
267:closed circuit
261:directly into
254:
251:
166:with standard
151:-SiGe models.
149:nanostructured
130:thermoelectric
107:semiconductors
91:
88:
13:
10:
9:
6:
4:
3:
2:
1095:
1084:
1081:
1079:
1076:
1074:
1071:
1069:
1066:
1064:
1061:
1060:
1058:
1044:
1038:
1035:
1031:
1025:
1023:
1021:
1017:
1012:
1005:
998:
996:
992:
981:on 2018-10-16
977:
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728:
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382:
378:
374:
370:
366:
362:
358:
353:
349:
345:
336:
329:
327:
325:
321:
320:natural decay
317:
313:
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307:
306:
301:
300:
295:
294:
289:
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283:
279:
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272:
268:
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248:
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236:
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220:
216:
212:
208:
204:
200:
196:
195:particle flux
192:
188:
183:
181:
177:
173:
169:
168:metallurgical
165:
161:
157:
152:
150:
146:
142:
139:
138:dimensionless
135:
131:
128:present good
127:
122:
120:
119:thermocouples
116:
112:
108:
105:
96:
89:
87:
85:
81:
80:
75:
74:
69:
68:
63:
62:
57:
56:
51:
50:
45:
41:
37:
33:
29:
23:
18:
1037:
1010:
983:. Retrieved
976:the original
934:
930:
909:. Retrieved
905:
892:
867:
863:
819:
816:Nano Letters
815:
801:
760:
757:Nano Letters
756:
749:
738:the original
733:
674:
668:
635:
631:
625:
582:
573:New Horizons
572:
568:
564:
541:New Horizons
540:
536:
520:New Horizons
518:
513:
506:
500:
498:
486:
478:
429:
423:
422:
413:New Horizons
412:
410:
341:
311:New Horizons
309:
303:
297:
291:
285:
275:
256:
184:
182:resistance.
172:temperatures
153:
145:temperatures
123:
101:
79:New Horizons
77:
72:
65:
59:
53:
47:
26:
638:: 161–165.
553:Kuiper Belt
373:Astroquartz
352:p-leg doped
348:n-leg doped
263:electricity
1057:Categories
985:2015-03-17
812:Chen, Gang
617:References
435:spacecraft
357:molybdenum
278:thermopile
247:phosphorus
235:electrical
219:molybdenum
191:solar cell
109:, such as
90:Properties
36:spacecraft
701:195862812
660:111227236
535:from the
431:Voyager 2
425:Voyager 1
393:generator
271:circuitry
199:heat flux
185:Near the
180:oxidation
178:and high
164:malleable
55:Voyager 2
49:Voyager 1
911:March 9,
884:20196558
844:19367858
793:20551131
785:22548377
595:See also
533:MHW-RTGs
377:insulate
361:tungsten
223:tungsten
102:Heavily
824:Bibcode
765:Bibcode
640:Bibcode
569:Cassini
565:Ulysses
537:Voyager
514:Cassini
508:Ulysses
502:Galileo
488:LES-8/9
479:Voyager
463:Neptune
451:Jupiter
391:of the
381:circuit
305:Cassini
299:Ulysses
293:Galileo
287:Voyager
73:Cassini
67:Ulysses
61:Galileo
30:(SiGe)
882:
842:
791:
783:
699:
689:
658:
473:(1832
461:, and
459:Uranus
455:Saturn
369:copper
316:Pu-238
308:, and
231:copper
207:vacuum
126:alloys
76:, and
1007:(PDF)
979:(PDF)
972:(PDF)
902:(PDF)
789:S2CID
741:(PDF)
730:(PDF)
697:S2CID
656:S2CID
561:Pluto
545:Pluto
467:decay
324:Watts
243:boron
215:space
134:power
124:SiGe
104:doped
913:2023
880:PMID
840:PMID
781:PMID
687:ISBN
571:and
499:The
428:and
342:The
259:heat
237:and
115:SiGe
40:NASA
939:doi
872:doi
868:114
832:doi
773:doi
679:doi
648:doi
636:685
491:).
443:MHW
187:Sun
1059::
1019:^
1009:.
994:^
951:^
933:.
921:^
904:.
878:.
866:.
852:^
838:.
830:.
818:.
810:;
787:.
779:.
771:.
761:12
759:.
732:.
709:^
695:.
685:.
654:.
646:.
634:.
567:,
475:°F
457:,
453:,
395:.
367:,
363:,
359:,
302:,
296:,
290:,
229:,
225:,
221:,
189:,
70:,
64:,
58:,
52:,
988:.
945:.
941::
935:8
915:.
886:.
874::
846:.
834::
826::
820:8
795:.
775::
767::
703:.
681::
662:.
650::
642::
485:(
471:K
441:(
113:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
