Difference between revisions of "Helium"

From Lunarpedia
Jump to: navigation, search
m (Reverted edits by 200.238.102.162 (Talk); changed back to last version by Mdelaney)
Line 1: Line 1:
''Helium 3'' is a rare isotope of the element [[Helium]], consisting of a nucleus with two protons and one neutron.  The approved abbreviation (for physics use) for Helium-3 is <sup>3</sup>He, however, the abbreviation He3 is also seen.
+
[https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=341 nexium online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1138 midi ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=156 sonyericsson ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031c4.htm generic paxil] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832221) free midi ringtones] [http://sand-stars.blogspot.com valium sale] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1086 ambien online] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$124 free sprint ringtones] [http://orladron.jubiiblog.de/ adipex online] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=316 ativan online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1091 buy nexium] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/zyxuwu.htm sagem ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832199) ativan online] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=336 free mono ringtones] [http://delricc.blogdiario.com/ cheap lorazepam] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=327 free ringtones] [http://taroelt.jubiiblog.de/ free mono ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=147 free real ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031b2.htm generic ativan] [http://discussions.csbsju.edu/general/messages/25/gejobi-229.html phentermine online] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/popydi.htm generic norco] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1142 free ericsson ringtones] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$92 buy cialis] [http://www.forumhosting.org/forum.php?mforum=acdrago ultram online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832229) free nokia ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=129 cheap levitra] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832237) real ringtones] [http://cacorol.blogdiario.com/ free ericsson ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1104 cheap ortho] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832211) free ringtones] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=353 free samsung ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832206) order cyclobenzaprine] [http://relgetvar.jubiiblog.de/ cheap wellbutrin] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=349 free punk ringtones] [http://pasorbas.jubiiblog.de/ cool ringtones] [http://vigetc.jubiiblog.de/ buy clomid] [http://livior.blogdiario.com/ free alltel ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1106 lortab online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832207) online diazepam] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1130 sagem ringtones] [http://www.forumhosting.org/forum.php?mforum=sajohnst ativan online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1123 motorola ringtones] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$105 nextel ringtones] [http://racalmon.jubiiblog.de/ buy meridia] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1115 free nokia ringtones] [http://algetca.jubiiblog.de/ cheap paxil] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1132 sony ericsson ringtones] [http://silly-n.blogspot.com best bonus casino online] [http://delelro.jubiiblog.de/ sprint ringtones] [http://www.forumhosting.org/forum.php?mforum=vipasac free alltel ringtones] [http://www.forumhosting.org/forum.php?mforum=lirolsit buy xenical] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$130 tramadol online] [http://www.forumhosting.org/forum.php?mforum=coeignus buy fioricet] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=347 polyphonic ringtones] [http://www.forumhosting.org/forum.php?mforum=rebangas buy carisoprodol] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$90 buy ativan] [http://getnoel.blogdiario.com/ ambien online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832196) alltel ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1097 clomid online] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/pecybu.htm alprazolam online] [http://www.forumhosting.org/forum.php?mforum=notrocvi samsung ringtones] [http://boeldron.jubiiblog.de/ free nokia ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1078 adipex online] [http://basor5or5.blogdiario.com/ free verizon ringtones] [http://www.forumhosting.org/forum.php?mforum=acrolbas free kyocera ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832246) tracfone ringtones] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/votebu.htm free qwest ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031ad.htm generic xanax] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/pyhux.htm clonazepam online] [http://www.csun.edu/learningnet/discussion/file.php?0,file=133 buy xenical] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=319 free cingular ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=119 cheap cialis] [http://www.rso.cmich.edu/prevet/messageboard/000031c1.htm generic alprazolam] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832227) cheap nexium] [http://www.csun.edu/learningnet/discussion/file.php?0,file=116 cheap fioricet] [http://sitracget.blogdiario.com/ funny ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=144 mp3 ringtones] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=362 cheap ultracet] [http://trocgetou.jubiiblog.de/ cheap ativan] [http://www.csun.edu/learningnet/discussion/file.php?0,file=152 free verizon ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031b0.htm diazepam online] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=325 ericsson ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1110 online rivotril] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/nini.htm free ringtone] [http://forum.kharkiv.edu/SForums/topic.asp?TOPIC_ID=309&FORUM_ID=3&CAT_ID=3 carisoprodol online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832255) xanax online] [http://cochibas.blogdiario.com/ free free ringtones] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$125 free tracfone ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=125 vicodin online] [http://pasricac.blogdiario.com/ wwe ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=113 buy phentermine] [http://www.csun.edu/learningnet/discussion/file.php?0,file=135 cyclobenzaprine online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832250) verizon ringtones] [http://bascnadar.blogdiario.com/ buy hydrocodone] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=371 buy xenical] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832218) levitra online] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=329 order hydrocodone] [http://forum.kharkiv.edu/SForums/topic.asp?TOPIC_ID=316&FORUM_ID=3&CAT_ID=3 meridia online] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=343 free nokia ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031af.htm ultram online] [http://www.csun.edu/learningnet/discussion/file.php?0,file=111 cheap soma] [http://www.csun.edu/learningnet/discussion/file.php?0,file=138 order propecia] [http://eleltrac.blogdiario.com/ buy ativan] [http://www.forumhosting.org/forum.php?mforum=lebowles adipex online] [http://getsitolo.jubiiblog.de/ lorazepam online] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$114 samsung ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1133 mono ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1125 free sprint ringtones] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=355 soma online] [http://cagetca.jubiiblog.de/ celexa online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1080 buy vicodin] [http://discussions.csbsju.edu/general/messages/25/gyxex-235.html buy cialis] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=358 sonyericsson ringtones] [http://ryu-jounetsu.blogspot.com canadian casino online] [http://rochili.jubiiblog.de/ cheap cyclobenzaprine] [http://www.forumhosting.org/forum.php?mforum=laoubo qwest ringtones] [http://ricvicna.blogdiario.com/ free polyphonic ringtones] [http://pasbasor.blogdiario.com/ ultram online] [http://eltc4tric.jubiiblog.de/ cheap xanax] [http://www.csun.edu/learningnet/discussion/file.php?0,file=142 tracfone ringtones] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1121 free qwest ringtones] [http://ellapas.jubiiblog.de/ lipitor online] [http://forum.kharkiv.edu/SForums/topic.asp?TOPIC_ID=312&FORUM_ID=3&CAT_ID=3 ultram online] [http://www.csun.edu/learningnet/discussion/file.php?0,file=136 nexium online] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$118 free sony ericsson ringtones] [http://discussions.csbsju.edu/general/messages/25/xyli-236.html ativan online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832257) cheap xenical] [http://www.rso.cmich.edu/prevet/messageboard/000031b1.htm generic cialis] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$91 cheap carisoprodol] [http://www.forumhosting.org/forum.php?mforum=laerzel free sagem ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031b4.htm generic meridia] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1120 free nextel ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832194) cheap tramadol] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=317 carisoprodol online] [http://bondich.blogspot.com mixing valium and xanax] [http://eltaric.blogdiario.com/ norco online] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/xikuzo.htm generic valium] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=322 cyclobenzaprine online] [http://pasbasbas.jubiiblog.de/ clonazepam online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832216) kyocera ringtones] [http://forum.kharkiv.edu/SForums/topic.asp?TOPIC_ID=317&FORUM_ID=3&CAT_ID=3 cheap adipex] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1131 sonyericsson ringtones] [http://www.rso.cmich.edu/prevet/messageboard/000031ac.htm cheap carisoprodol] [http://www.csun.edu/learningnet/discussion/file.php?0,file=130 cheap hydrocodone] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/ronut.htm free sony ericsson ringtones] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=334 cheap meridia] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1108 zanaflex online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1031?id=atch1129 cingular ringtones] [http://raccaelt.jubiiblog.de/ viagra online] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=369 wwe ringtones] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/digesyv.htm nokia ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832225) mtv ringtones] [http://eltvivi.blogdiario.com/ cheap vicodin] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/bipivu.htm generic meridia] [http://www.forumhosting.org/forum.php?mforum=getcoro sony ericsson ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832238) free sagem ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832236) free qwest ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832243) sony ringtones] [http://www.forumhosting.org/forum.php?mforum=coephrai cheap tramadol] [http://www.rso.cmich.edu/prevet/messageboard/000031d2.htm free qwest ringtones] [http://letocoer.jubiiblog.de/ free polyphonic ringtones] [http://forum.kharkiv.edu/SForums/topic.asp?TOPIC_ID=310&FORUM_ID=3&CAT_ID=3 xanax] [http://www.csun.edu/learningnet/discussion/file.php?0,file=155 free sagem ringtones] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/ciby.htm free funny ringtone] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=356 sony ericsson ringtones] [http://www.csun.edu/learningnet/discussion/file.php?0,file=121 viagra online] [http://www.csun.edu/learningnet/discussion/file.php?0,file=141 free free ringtones] [http://ricrotroc.blogdiario.com/ free samsung ringtones] [http://eltlili.jubiiblog.de/ buy ambien] [http://ouglova.blogspot.com valium half life] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832248) ultram online] [http://www.csun.edu/learningnet/discussion/file.php?0,file=157 free sony ericsson ringtones] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/rujop.htm phentermine online] [http://woolygrrl.blogspot.com valium side effects] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$134 valium online] [http://www8.vjc.edu/EnvironmentalClub/discuss/msgReader$95 cheap diazepam] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/tubonyh.htm free samsung ringtone] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1113 hoodia online] [http://acdronou.jubiiblog.de/ cheap diazepam] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832224) mp3 ringtones] [http://alcodom.blogdiario.com/ cheap viagra] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=370 xanax online] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832241) cheap soma] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=312 but adipex] [https://www-internal.slac.stanford.edu/glast/integrationtest/online/Forum/topic.asp?TOPIC_ID=318 cheap cialis] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1030?id=atch1105 order pharmacy online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1066 soma online] [http://coracou.jubiiblog.de/ hydrocodone online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1094 didrex online] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1087 cheap lorazepam] [http://www.forumhosting.org/forum.php?mforum=covarrel free funny ringtones] [http://lasitdron.jubiiblog.de/ cheap sildenafil] [http://src.moffitt.usf.edu/sf/sfmain/do/downloadAttachment/projects.jaffy/tracker.bug_tracker/artf1029?id=atch1084 cheap levitra] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/nyzihyp.htm free tracfone ringtone] [http://manka-kapak.blogspot.com casino craps online] [http://www.rso.cmich.edu/prevet/messageboard/000031c8.htm free ringtones] [http://www.forumhosting.org/forum.php?mforum=oudronacel cheap didrex] [http://www.hcs.harvard.edu/~twiki/pub/Main/CoyarCharline/kukoti.htm cheap cialis] [http://www.hcs.harvard.edu/~twiki/pub/Main/AngelKristofer/sinyfu.htm mp3 ringtones] [http://pathology.jhu.edu/N/n.web?EP=N&URL=/MCGI/SEND1^WEBUTLTY(200,832228) free nextel ringtones] ''Helium 3'' is a rare isotope of the element [[Helium]], consisting of a nucleus with two protons and one neutron.  The approved abbreviation (for physics use) for Helium-3 is <sup>3</sup>He, however, the abbreviation He3 is also seen.
  
 
Since most of the Earth's helium is produced by alpha-decay of Uranium isotopes, resulting in <sup>4</sup>He (the most common isotope of Helium), <sup>3</sup>He is rare on Earth.  It is comparatively more abundant in non-terrestrial sources, although even in non-terrestrial sources, only a small fraction of helium atoms are Helium 3.   
 
Since most of the Earth's helium is produced by alpha-decay of Uranium isotopes, resulting in <sup>4</sup>He (the most common isotope of Helium), <sup>3</sup>He is rare on Earth.  It is comparatively more abundant in non-terrestrial sources, although even in non-terrestrial sources, only a small fraction of helium atoms are Helium 3.   
Line 10: Line 10:
 
It has been proposed that <sup>3</sup>He might be a possible fuel for a [[Nuclear Fusion]] reactor to produce energy using the nuclear reaction:
 
It has been proposed that <sup>3</sup>He might be a possible fuel for a [[Nuclear Fusion]] reactor to produce energy using the nuclear reaction:
  
<sup>2</sup>D + <sup>3</sup>He -->  <sup>4</sup>He + <sup>1</sup>H
+
<sup>2</sup>D   <sup>3</sup>He -->  <sup>4</sup>He   <sup>1</sup>H
  
 
This reaction has the advantage over the more-commonly proposed D-T fusion reaction that the reaction produces only charged particles (an alpha particle and a proton), with no production of neutrons.  However, the corresponding difficulty is that the D-<sup>3</sup>He reaction has an ignition barrier that is twice as high as the barrier to igniting D-T fusion, because of the fact that the Helium nucleus has twice the charge of a Tritium nucleus.   
 
This reaction has the advantage over the more-commonly proposed D-T fusion reaction that the reaction produces only charged particles (an alpha particle and a proton), with no production of neutrons.  However, the corresponding difficulty is that the D-<sup>3</sup>He reaction has an ignition barrier that is twice as high as the barrier to igniting D-T fusion, because of the fact that the Helium nucleus has twice the charge of a Tritium nucleus.   

Revision as of 05:31, 28 April 2007

nexium online midi ringtones sonyericsson ringtones generic paxil free midi ringtones valium sale ambien online free sprint ringtones adipex online ativan online buy nexium sagem ringtones ativan online free mono ringtones cheap lorazepam free ringtones free mono ringtones free real ringtones generic ativan phentermine online generic norco free ericsson ringtones buy cialis ultram online free nokia ringtones cheap levitra real ringtones free ericsson ringtones cheap ortho free ringtones free samsung ringtones order cyclobenzaprine cheap wellbutrin free punk ringtones cool ringtones buy clomid free alltel ringtones lortab online online diazepam sagem ringtones ativan online motorola ringtones nextel ringtones buy meridia free nokia ringtones cheap paxil sony ericsson ringtones best bonus casino online sprint ringtones free alltel ringtones buy xenical tramadol online buy fioricet polyphonic ringtones buy carisoprodol buy ativan ambien online alltel ringtones clomid online alprazolam online samsung ringtones free nokia ringtones adipex online free verizon ringtones free kyocera ringtones tracfone ringtones free qwest ringtones generic xanax clonazepam online buy xenical free cingular ringtones cheap cialis generic alprazolam cheap nexium cheap fioricet funny ringtones mp3 ringtones cheap ultracet cheap ativan free verizon ringtones diazepam online ericsson ringtones online rivotril free ringtone carisoprodol online xanax online free free ringtones free tracfone ringtones vicodin online wwe ringtones buy phentermine cyclobenzaprine online verizon ringtones buy hydrocodone buy xenical levitra online order hydrocodone meridia online free nokia ringtones ultram online cheap soma order propecia buy ativan adipex online lorazepam online samsung ringtones mono ringtones free sprint ringtones soma online celexa online buy vicodin buy cialis sonyericsson ringtones canadian casino online cheap cyclobenzaprine qwest ringtones free polyphonic ringtones ultram online cheap xanax tracfone ringtones free qwest ringtones lipitor online ultram online nexium online free sony ericsson ringtones ativan online cheap xenical generic cialis cheap carisoprodol free sagem ringtones generic meridia free nextel ringtones cheap tramadol carisoprodol online mixing valium and xanax norco online generic valium cyclobenzaprine online clonazepam online kyocera ringtones cheap adipex sonyericsson ringtones cheap carisoprodol cheap hydrocodone free sony ericsson ringtones cheap meridia zanaflex online cingular ringtones viagra online wwe ringtones nokia ringtones mtv ringtones cheap vicodin generic meridia sony ericsson ringtones free sagem ringtones free qwest ringtones sony ringtones cheap tramadol free qwest ringtones free polyphonic ringtones xanax free sagem ringtones free funny ringtone sony ericsson ringtones viagra online free free ringtones free samsung ringtones buy ambien valium half life ultram online free sony ericsson ringtones phentermine online valium side effects valium online cheap diazepam free samsung ringtone hoodia online cheap diazepam mp3 ringtones cheap viagra xanax online cheap soma but adipex cheap cialis order pharmacy online soma online hydrocodone online didrex online cheap lorazepam free funny ringtones cheap sildenafil cheap levitra free tracfone ringtone casino craps online free ringtones cheap didrex cheap cialis mp3 ringtones free nextel ringtones Helium 3 is a rare isotope of the element Helium, consisting of a nucleus with two protons and one neutron. The approved abbreviation (for physics use) for Helium-3 is 3He, however, the abbreviation He3 is also seen.

Since most of the Earth's helium is produced by alpha-decay of Uranium isotopes, resulting in 4He (the most common isotope of Helium), 3He is rare on Earth. It is comparatively more abundant in non-terrestrial sources, although even in non-terrestrial sources, only a small fraction of helium atoms are Helium 3.

The Moon is a source of 3He, which is implanted into the lunar regolith by the solar wind. Helium is present in the soil in quantities of ten to a hundred (weight) parts per million, and 0.003 to 1 percent of this amount (depending on soil) is 3He.


Helium 3 as a Fusion Reaction Fuel

It has been proposed that 3He might be a possible fuel for a Nuclear Fusion reactor to produce energy using the nuclear reaction:

2D 3He --> 4He 1H

This reaction has the advantage over the more-commonly proposed D-T fusion reaction that the reaction produces only charged particles (an alpha particle and a proton), with no production of neutrons. However, the corresponding difficulty is that the D-3He reaction has an ignition barrier that is twice as high as the barrier to igniting D-T fusion, because of the fact that the Helium nucleus has twice the charge of a Tritium nucleus.

Gerald Kulcinski's group at the Fusion Technology Institute of the University of Wisconsin-Madison has operated an experimental He3 fusion reactor for an extended period, on a non-governmental research budget (ref: Hedman, Eric; (Monday, January 16, 2006). "A fascinating hour with Gerald Kulcinski" (HTML). The Space Review. Jeff Foust, Ed. Retrieved on 2007-03-04), however the reactor has not achieved energy balance or breakeven.

So far, D-3He fusion has not yet demonstrated net energy production ("break even"). Commercial He3 reactors are long way in the future.

Value of Lunar Helium 3 in Today's Market

Since He3 has a high market value today, it might be worth collecting He3 from the Moon today simply to sell into the existing terrestrial market.

Current market price for He3 is about $46,500 per troy ounce ($1500/gram, $1.5M/kg), more than 120 times the value per unit weight of Gold and over eight times the value of Rhodium.

Question: can we reduce the cost of recovering He3 from the lunar surface to that level, e.g. $1500 per gram? What would be the capital cost of setting up a small He3 production facility on Luna?

Would it depress the market price today? That depends on the size of the market, and there is not much data on that.

The US Tritium and helium-3 stockpile sizes are classified, because they give a hint as to how many US nuclear weapons are still functional. According to Wikipedia “approximately 150 kilograms of it (He3) have resulted from decay of US Tritium production since 1955.” We could assume a similar quantity has been accumulated in the ex-USSR, and perhaps additionally from other thermonuclear powers (UK, France, China).

Today, the world's supply of Helium-3 can probably be counted in hundreds of kilograms, value of 100 kg would be $150M. So the total stockpile value today is probably about half a billion USD.

The US DOE does sell He3 commercially, but how much of the present stockpile has actually been sold on the open market? Not sure if that number is publicly available.

But for arguments sake let us start at the level of collecting 100kg of He3 from the Moon and assume its value would be $150M.

Well alas even those number do not look good.

The cost of soft landing even a small probe on to the lunar surface would easily cost that much or more. How much He3 could a small lander manufacture? How many grams per day?

Well that of course depends on the production method.

A commonly discussed method is cooking the regolith to about 1400 degF or 760 deg C. This would require a lot of energy, requiring the lander to have either a nuclear source (either Nuclear Fission or RTG, or large solar panels (see Solar Power).

Basalt has specific heat capacity of 0.24 cal/g/degC or 0.84 KJ/kg degK.

To heat 1kg of basalt by 700degC requires about 600 KJ

Best lunar regolith (in the Maria regions) is 0.01 ppm of He3

So the 600 KJ will yield 0.01 milligrams of He3

So 600 Watts power source could produce 0.01 mg He3 per second = 0.6 mg/minute = 36mg/hour = 864mg/day = 315 grams per year

Whether this business concept is viable depends on how quickly we want to amortize our investment.

Let us say our target is to produce 100 kg He3 in one year, then we need a power source of about 200 KW. That would give us a revenue stream of $150M per year assuming the He3 market does not become flooded and the price drops.

How much would it cost to set up a 200KW power source on the Moon?

A Solar Power based system would be in darkness 50% of the time, so would need to operate at 400 KW. If it were on a lunar polar mountain top it might be in near continuous illumination. Let us assume that best case of 100% lighting.

Assuming PV 10% efficiency and a fully steerable array, this would need an area of about 2,000 square meters, or about 45 metres square.

A simple non-PV solar reflector could be near 100% efficient, needing only 200 sq-m or 14 metres square, or aperture.

Setting up a 14 m aperture mirror on the Moon would be a major engineering challenge, although fortunately would not need to be particularly accurate, certainly nothing like as difficult as an astronomical telescope mirror.

How much would it weigh?

Would a Nuclear Fission power plant have better performance per kilogram of lander payload?

Maybe other contributors are interested to develop these lines of thinking.

More thermal analysis needs to be done. For example, might it be possible to recycle the heat using some form of cogeneration. Such as use the hot waste regolith, after it has been processed, to pre-heat the next incoming batch of raw dust, and thus reduce the number of solar joules needed?

That could greatly reduce the size of solar array needed and/or significantly increase the system mass throughput.

Extraction

Baked Regolith

A commonly discussed method is cooking the Regolith to about 1400 degF or 760 deg C.

Here is a reference with some details (1989, H. H. Schmitt et al):

http://fti.neep.wisc.edu/pdf/fdm817.pdf

They describe three steps: 1) heat to a few hundred deg C to drive off the volatiles 2) fractional distillation to decant off the heavy volatiles 3) separate He3 from the He4 using standard superleak process

Two challenges are devising a method to process large quantities of regolith as the He3 is at a low concentration, and providing a high power thermally efficient heat source on the Moon.

This would require a lot of energy, requiring the lander to have either a nuclear source, or large solar panels.

Basalt has specific heat capacity of 0.24 cal/g/degC or 0.84 KJ/kg degK.

To heat 1kg of basalt by 700degC requires about 600 KJ

Best lunar regolith (Maria) might be 0.01 ppm of He3

So the 600 KJ will yield 0.01 milligrams of He3

So 600 Watts power source could produce 0.01 mg He3 per second = 0.6 mg/minute = 36mg/hour = 864mg/day = 315 grams per year

Applications

  • Medical Lung Imaging
According to Wikipedia:
http://en.wikipedia.org/wiki/Helium_3
Details on this experimental application of He3: http://cerncourier.com/main/article/41/8/14

Links

External Links


Work on this article has outpaced copyediting on it. You can help Lunarpedia by formatting, editing, or tidying it.