TRIP REPORT - DEVELOPMENT OF BC-13 THERMOELECTRIC GENERATOR

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03424A001200080003-9
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 30
• Document Creation Date: December 22, 2016
• Document Release Date: February 13, 2012
• Sequence Number: 3
• Publication Date: September 24, 1959
• Content Type: MEMO

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C7~lCe McY1ZOY~G~~ZGGZLnZ NITED STATES GOVERNMENT
TO DATE: $g ember` 1959
The Files - Contract 111-
13224-9 24:- per,
.,
-
_
,
O ~~ a/?. ' ~
~
~ ??~ ~~~ Haase ~Zo
~
~
FROM % ?4~1~ ~?F~PQ~- ?v~i -~-r`~~~C.~ ?Vr~
susJECT: Trip Report - Development-ofd=ermoele`a~ric`~Geiiera~or`"~"r
1. On 21 September 1959 a trip was made to
under ontract 111-13224-9. Present at the discussions were:
25X1
25X1
25X1
2. The contractor has completed fabrication of a test model of
the BC-13, which has 101 thermocouples connected in a series-parallel
to give an open circuit voltage of 22.5 volts with a temperature differ-
ence of 1,000oF. The m~Yinn~m output of this generator is approximately
9 watts into a matched resistive load. The overall performance of this
model is satisfactory and the contractor will make delivery of the BC-13
around 1 November 1959. After a series of tests on this model and a
second model, the contractor will build a third unit for delivery.
3. The BC-13 will have two equal output voltages which can be used
for charging 6 or 12-volt batteries. In addition to the generator itself,
there will be provisions for connecting a portable propane tank, a
five-foot hose to connect it with a larger propane tank such as used in
house trailers, and an indicating device to indicate ma~dsmam output. This
indicating device will simpip be a voltmeter with a lrelloW green-red ~tase
to indicate proper operating range. The propane burner in the generator
is a removable device and very easily cleaned. This burner has a capa-
bility of giving a hot junction temperature of 1,170?F. The cold temperature
varies depending upon ambient temperatures, but runs around 160?F. The
generator is approximately 10 inches in diameter, including the radiated
fins, and approximately 10 inchea high. The total weight of the unit will
be approximately 15 lbs., not including the propane tank.
to monitor progress of the TO-watt thermos ec ric genera or
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inn ~~~,_ -.
SUBJECT: Trip Report - Developanent of BC-13 Thermoelectric Generator
Attachment:
Thermofax Copy of Performance and Enviro~ental
Test Results of SNAP-III
cc: ~ R+D'"SSib3ect Files
R+D Zab
SPS/AF
OC-T/CT/OR
Monthlry (2 )
EP Chrono
~~~~?~~~ U ~ ~
~~
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~`~ ~- G~
Pertorarance Data and Cnviras~~ental 'fast ~tesul is of SNAP III
Fred N. Ituttm~.tn and Louis -.1'. chose ?
The poloni~ue fueled SN.t~' YII thermoelectric generator
dioplayed on Yres3dent ~iser~liower ?s desk on Jar-uary 16 of this
your has produced electrical poLVer continuously for ovrr 3000
dre and is still operating on tt~e original tuc~l charge. A
second polonius~Nfuelod unit, which powered an amateur radio
otution ut The .1tom Fair in .tpril, hest also run contiauonoly
and without incident until the present tiwoo These operating
tiwea are a testi~sonial to the longevity and reliability of
the devieeo
SNAP III was developed by Th? martin Co+apaoy in con~nactiou
with l~inaeaota A>tining and l~aautacturing Company .and bound
Laboratory. It i$ part of the .S~-syster~ for S~uclear Auxiliary
Power deraoa8tration program for?`raadioisotopic fueled thereto-
electric and Lhermionic converters aponr~ored by the l~isoile?
Project Branch of the Atomic tsnergy Cor~caisaloA.
Th? detailed design problems And constructional leaturea
o! SNAP IIZ have been diacusaed in !tats. 1 and 2~ However, a
brief description of the generator provides s uaotul back-
ground for the data and-test results to 6e present?d. stn
artist?s conccp'c of the generator is sho?n is F'ig. 1. Th?
center cylinder repr4sonts the polonium rud.~oisotope fuel
capsule which is contained in the a:olybdonu? block. Surrounding
th? heat source arc 54 r~emiconauctQr theru~oelectric elemeettr
waking up 2? the~ocouptes~, f;sch thermocouple eoasiats of a
P-type sodium duped lead tc~I~.urid? log and a N--type iodine-
doped lead telluride leg p.ACed in electrical aeries and in ~~
thermal short. Iodin? dopjlri~; is used in Place of the on final ~~
bisp~uth doping i'or reasons of quality control. Lath leg ~a ~ ~~
wade of two difterentjy doped ao~jenta ao that each operatoa
Kith u~axinuc~ eFPectiwenuss within its tewperature r~o~g?. A
lr,~ction of the radioisotopic hQat flows through the lead
telluride el`?r?:o~nt . `xe cU? d ~u:~act~f on electrical connection fie moldered ~~
while the hot ~taz~ctiEcn e2ecty teal :end thermal continuity la
naintc~ined by a co~.pr~~gWivo ~gr~.ng-leacl+ed conLacto Th? ratios
of the spr~.n,3 pa~oF,~;~re and tecnpc:r~ature is ranch that the lead
telluri.dc ~.:~ psrtir~Zl;~ fused t~ ti.? hot $hoeo This technique
gives elc~et:3cal continuity wen though aubli~aation oay take
place frc~ tho~ hot ,js~nctiozt area,.
'This +vork was apoc-sored ~by the ACC under Contract Ho. dT(30-3~Z1~?
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;- ~
A detailed weight areakdown i$ 61ven i~a Table 1.
Obviou,ly, there are m~.iny ways of reducing the generator r-e1gMt
by reducing the woighte of individual components as well sa
by overall gsoaetricul uad detail redesig~~o A straigbt-
torward resdeaign~should double the watt/pound rating o! the
present unit.
?ABLE: 1
COADODej1t ~O `O~ 8~AP I~
r ~~ ~a~r~
Inaulatio~
Caa?
Cold Junction Iloasin~
Beat bourco
T'ben~oaouple E:le.eats
ltot Shoes
.Cold Junction Socket
bpriage, Sarews Dad -~~aahero
E:lewent Cap (pair sad wire)
Assewb.led ieigbt
The initial charaateristic~ of the aeooad pola~ier~h~
1li~lAP III are tsbulated is Table 2 for both coon erbiMt dIN
$?iw~lated space coaditiona. Figure 3 gives a plot of tiN ~_
oorreaponding power oat ~ersue load re~istano? data. Ne~ti
thr redretion in output (and efficiency) due to the iaoreu~
in cold ~uaction tenporaturo in the vacuns en~rira-nnewt. Nr
plain i? Dade tbat the bell ~+etr arran6ereot aia~ulates spao~
=eosditions accurately. However, it does indicate the..resatin
ditterooce in portornance betMeeo rooms anbLtet and opaed
condition.
Inatrwaontul errors uod errors due to noa-oyuilibri~r
terperatuces probably average three per coat. Data trop a q'r+~
tenerator reproduce [airly well, but units vary io the~~
electric properties ~ttid ?lectcicol and tbernu coataot
reeistuacee such that overall ?tticienole? ditt~r M rwelr< ~
too pper cent. Alao, the data cover errerol ditterewt ~~~!t'g.
Mbioh were conatruotsd with dittere,t ia~-ulatora. '!lrat~ au
tbo ?leotrical pertoc~snc? data iqr, tbi? poplar shorld ~i MM` `'
~`
tarried M typiecil ratbcr than prey ?e.
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~~ ~ '~,
TAl31.k: 2
Initial Characteristics of Second t'o-210 Fueled StiAn III
!toes. Aa.bient l3e11 .Jor
Poloniue?-210 therrcr~l in[~ut, w
80.2
80.3
i~lectrioal out[~ut (3 ohR toad), w
3.40
Z.~
lNatNut lwtential, v
3.20
lt.88
Overfill etticienay, ~
Ei.?S
S.SQ
t[ot ~uaetion tewperature, ?t~'
900
880
Cold ~uaation teuperdture, ?h'
1?3
~3
".'eight, lb
4
4
!le ight , in .
6
a
Diameter, in.
4.8
4.8
Internal generator pressure, area Ilg,
?irgc~n-"ethane
ZO0
BOO
Dose rt~te ~t 1 a:eter, o?reo:/br
3.8
3.a
50~.o contusion exists :~s to what S. a!' III is. 3w-r iii
is n rubged prototype unit which bas o~jer;+ted roliobly for
long I~eriods. It has a me~eured efficiency of G.l3li in. roes
ar:bient conditions and a e~ousured etticiency of 8.8~i L1
sia;ulated space conditions. ~~lthough oae way sgaeese tiw
watts out of the generator in rood A:r:bient eonditioa~, it
ie, in general, a 2.8-~w unit in a speee enviroac.ent.
:11th~~- ugh ~N ?1N III is tar from thQ ulti^ata in d ireot oon-
versioa power su~:pliss, it does represent Available hardrnar~
capable of poprer densities of 2/3 w/lb:end energy deasitioa
of 1000 w hr/lb. The [;enerntor incorporates y.urs of
?.'innesotu ?~infng rand !laanlucturing Coo:pmny experience with
lead telluride thermoclectria elements for goa bursar
controls. Fabrication techniques Hdd detail deaigs lwve
been refined in the process of building a total o eight _
SN.1!' III unite. Tiro of these units have been loe~ded ~1th
isotopic tuQl and other electrically heated aodels are
undergoing test programs.
To truly optirri$e t?n isotopic theraoosleatric space
systen., a:eny parau~eters must be specified. Exact ewterial
pprroperties of the thprmoelectrics and the insulation want
be knowia. Electrical and they?al contact resistanoee at'e
needed. 't'he electrical load profile and regulation, s,iNia~
litetiaae, orbit data, structural tie-iu to vehicle, rehiole
temper8ture, and operating radiation shield requireneuta
e~ust be specified. Isotope availability, cost, dsnelogretltt
ti~.e and ground handling consider:~tioos i~apose coastraints
oa the design. Ilnze~rd considerations of launch about eoa
reentry also reflect on,the dssig:~. The~coatrollins
opptic~isation parameter tsuaa as, ~ss-gy au+.s`~ ?
glticienay, cost, sise) ^wt be deternided.
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Unless these iton:s r+re established, an analytical optimi-
antion ie futile. Obviou$ly, many of these itea.s Are a
wetter of engineering ~udger.ent and involve political as
well as technical eonaidertrtiona. One should keep in ~+ind
that an optia.isation is seldon~ better than its weakest
nssuo:pt ion.
It is interesting to note that fn the present unit,
the weight of the thermoelectric materi:~l is less than
1G9~ of ttie total gener:~tor woight. :llthough optia~ization
~rjlght increAso this percentage 8oa.ewhat, it is indicative
of practical designs. Clee~rly, dersfgns which optiaize
on the basis of thera~oolectric ?ateriol woight tyre likely
to be trallacious.
Analysis of thermoelectric generator perforcaacs i?
tares of Seebeck voltage, r~~sistivit~-, end ther~.al eon?
ductivity hFive been given in a number of references
(stets. 3 and 4). However, 5~.11~ III pertorrrunce will be
discussed in terms of heat balancQ. ,lesun~ing Thoa;pson
effects nre negligible.
~ Z
isotope ~ KTB (TH-rc) + KIns (G'r)(Th-Tc) ? .~.I - l r I
G generotor till gas (i.a. hydrogen or argon-
methane)
Peltier coo.~ticient
current
hot function temperature
cold,~unction temperature
internal gas pressure
.
,~, !
.
The intoroction of these tera:e accounts for the pertorwanoe
of the device. The effect of the generator till pressure
is shown in Fig. 4. Atypical volt-a~;pare curve is shown
in Fig. 5. 'The effect of Peltier aool~ng on the hot
function as a function of load resistance is illustrated.
~'he upper find lower crosses correspond to hot function
te~peraturea of 1000 r,nd 900?F, respectively. The slight
non-linearity is the ca~:bined result of ['eltier cooling
and shifting of the figure of serif with a change in hot
function tea~pereture.
A study of electrical power output in a bell 3~' versus
a loud reei$tance paraQetric in theroial power for vi~aunw
and one atmosphere fill pressure is shown in Figs. 4 and 0
!or two SiVAP III configurations. These geaerr~tors are
identical except that in the ens design the disaster of
the thersoelectric elesent i? redu~sd.to inor~q tho'
efficiency st lower power inputs by iaor+raa#~ tRo IMr!
~m~otion tswpsratmres. P'or
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 i
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~.
~fi..
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apc~co conditioais, tlae hi;;);~r:r po,vF~r aener ator rsx-y be rated at
around 2,~ 4~ and the lo;w:z? pore. trait, ,:it; 105 rr,, Note thbt a
hot j~inctioxz te:z:l:erxaif~rc:tio:~ ?n a sl~:ice ~:nvironmeixt sEriously decreaeor~
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respectivelyo l;oa~?~ve: , a4~ in~~ ti.izl j.n,~uf: os .,8 ~v would exceed
t~ho lso;; j~:actid~n te:n~~cr?rl~~ ~~a?~~ ~:o~a~?f,rzii~~t :i:l L.;le ~~acuu~ case
and rziui:t~ Lrli:~ r~;c>cte cf o~e~?.~^;i~~a, ~lon~~o i::,r.ca_.:sil~lea Conaidor
t.Flt; G~k,~t` 'Y-1rT~ .:.~t? ~n~3i:'.3.:;(1:.' :t :3 d;,~i i;1r~:I r'.:>' ~'~ ~.a.~~{l t?~~tl aII
$t13()f~~):lL.?i""@ ~!~ ~ '~Cit1.C2"?!; i;~'~;'-c !1~Ji ~ rr.+:1?~c} .v }. C~.1 Fl t:1~e1^tq;sl input
Ofi JFi 9l? .?C~7!-~^ G~l,1';,Y)tl?r: `.~~~1_',_rl w?t? :.C?t~ -. ~ a'.':? .i? i:L;.t;.rally but .would
be red~icel to 0, ;;5 ~1 a-t ~it2 ~~r~ !+`' ~, ;):i~.: -,;1 ~,~~, 'Phis modo
of ope~?4~.tsor~, ,~ic~.?au9 clrF~~.; n~~1; ca~~~;;4, i,t:~ ::?;.riuire:~iE'~t~c However
?
if tho gezsera~.'~ i':t1?. ~)rc.,a~l~rn it-, Pra~:c;t~ly prot;r:~wwed from
one atr,~ospile:~;: ini~~ilxl~y Lo v..c~,l;r~ rxt trle onu uf. li.~'e9 tha
Qlectrical ou:.~u~u rnrctzren~c,~sa2 io rset uf~d tole ~nisssion has beon
accompli.stz~?tI ~;?,tttl 1~ feti.?e:~ t~lern:r:.i ~v;~f,L~, tllt3~ i.ri the simplo
one atL~csnher: c~+~Fe 'T'hi:y n?~pre~.~ea~?ts ra fey ~1 i.ra~?F?stment
snvint; of aves? o~~e--tllirde P2c:.i-.~~~~ or t.lwa c~xtrc~:~e expense
Of isntcpe fuetp this c?cotloszy ic;,; ~.at ~c~f~ccf~~.~ ti;~,^~.h the design
effort Y:1 add:..",ion, arl .#t~cic?ei?t:.il. x?er,~t? ie: that the
electrical ou,,~?~~c is x?s~t rcr;ect by ?thi~: ~~.r?oce~3ur~*~
T3ais teche)~ic,ue u11;~~vs ",he ~;rcat.?ra%os~ de?;ya~n to be oPtiaised
for mt~::~.u~~u~ ef';~icie-tcy gat the rL':c! cf life (uz;cczllly about a
half-1,Lfe) ~vithar_t exc~~c~d3r~? thca':noolet:tric motoritll operatin`
temperai;ure cvi-th ~xn initial ch,-r~c~ of fc~e~L o 5o~.etir~ee the
miano~er?9 "pr-~se~^ flat'i;cal~~r*.~,?" is ~;~.ve~n to ir!lis i'erature inc~tead
of thn more der~criptxve tcr?c.~9 "heist dumpi3l~"o 1[t should be
kept in mind th~it the ttle~?r:~ill ~hcsrt is prig*~orily r~ri isotope
economy ~nt~aaurt~ r~racl thtrt the posy~~r fl~tterlicll; 13 ~uarely an
extra dividondo
Brut durjpii~~` will n1:5o ir-crt~a.~ao tt1+3 watt/pound rating of
tho gerlerutor.,
' See?er~l m;~thr~~la of achloe.~~.ai~ ~) ~rr :~ud;c~r~.ed., A raettlocl that loolta
` promi~cin~; v-~it1; thQ Si~.ir' ? ~1 ~,axlctiarl also aide in
packing irl a:orQ thermal pr~wer irlititlllyo) '!fie power flattanlle~
duo to heat dur~a~ing is r~l;so GtlorYtl~ ;Mors: is under way at Martin
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to acco~,plish ttris. It is itaterestin~; to Hate that the
generator +vus nut desibnc~d ty:iti~ tYlis feat~rrQ in mind. .1~ain,
the preas~ure data should be c~onsi.ricred a~ typical rather than
exact beczruse or signific~~,jt variations a::aon5 generators as
to thcx'Hce-1 cent:ict resist~~ncew~ ~~ctcrs the ;,as filch conduction
across junctio~n:s is rcrsovecl ley c.~v~~cuatin~ file generator. ~ The
lose of film cuzrc7uct3a:~ raau~.t:.; zi grec-t~a? Llta~r~T~oeloctric
element tcrineraturea .fur a gzvcn E>ower input oncl is reflected
in povrar perf orntiunces =,
The thermral insulation in the hemispherical domes is
cwapressed N:in-K, 13010 'The Sx? material has a coapressive
strength of ?00 psis f'o~vclared asin-K surrounds the eleAenta
themselves and ib compacted try vibration during assearblr.
Thespring force err an individual element at room.tewpera-
ture is approximatcrly 202 1b end incroaspa to about 5.1 lb
at 1100?F'. The ad~ustinb screw has n thread pitch of 20
threads/ino and v sprin6 rate of 175 lb/~.n. The screw 'ia
set 1/3 turn from the tra? length of 'spring. 'These tension
parameters vary with rsiasion~
The dyna~iic tests to be cliacussod were in accordance with
apecificationa fiubaaitted by Jet t~rapulsion Ltiboratory. A
detailed report of ttiasv testa will soon be adaileble in
Ret. S.
The vibration test utilized a Galidyne vibration agates
ModQl No. 177A6 The test program consisted of a sinusoidal
vibration of 5 g rmg from 15 to 1500 cps, superimposed ou a
rmdoa Signal of 5 g rms, band-limited bet?~voen 15 to 1500
cps for S min. The second portion of the tape consisted of
a ainugoidnl vii ration oi' 8 g r:~a from 5a0 to 1500, super-
ispoaed on a rrciuiom 63.gnccl of S g rcoz~, Uf~:nd--limited between
la to 1500 cps for 5 ~nia14 TWO text CycAes were conducted 1A
eacA of tF'e 'tlir~~~c: oi?t;:oeonal pluno~ sbu~vn in 1'i~**~ 130
The frer~trency response of the ~shutcrzr, mountin6 plate
and test f iA2care orris equalized by use oi' the system equaliser
and a peaty notch filter. Krorattite bond ps~ss filterB vrere
used to bring the rel_utfve level cfo~m 3 db at 1500 cps and 8.a
db at 15 cps 'Thc~ gerorutor in i~ta fixture and mounted oo the
Calidyne ~sibrtctor is shown in Vigo 13. A tyt~icul equalization
curve is givcrn in Figs 14a
Prior to each test, the generator eras allowed to reao6 a1f
equilibriius (rooms ambient) povrQr input, poser output, and
Got ~unct~.an and cold ~unctiou tescperature+s. 'These psrasetera
were ?oaitored throughout Lhe tests.
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i7r-e vfi:ra~;a4~ri Lost: ~-it~~.~~si ~?~l.y ;~ ,~au~.l cir~ap in e.ffieic~ney
in tine x anti z p.L:::t;~et~?~ '~:ae 1.~.::?~~~::>t eif~:::~~. ~rf~:~ ~:a Lhe y plazas
and l.s etaows~ :ass i'~.go ~.:s- i~i~s`L.: '.:1t,-~, t:i~ i~:'n:tcin~acy drop is
cons ~o~t t~i'4,ci? rE~r~wra:~r.~; f t; r:: ,~'..:~~t:~ u~yti ~. ~ftf ~;t?~x?atory forcco
is di.scontfcauede Ir~__ ~?~ex~,}~. r:~..~;:: ; t.l~.e ~eitc~~at;t~? cc:.~i~l.~tely re-
._
1_ crs~`;p,a.
~~~~:~~ 10 ~:~.:~~ In t;he tyorst case
e~.:ci Ats ordgie~~~
~gv
~
_
_
~' , , ~~ decr?e>~~d a~11y 0 3;~
of t.-e* y plrazae9 #:hG ef.~ i_cx~:.r.c:;;~ :~:u..~ ~ o
!danf.tarin~; o? kite ~.~1;(?~ cl?-?r ri~tpufc sho~v::d u r~uall ripple
in tt~e x rand z g.anc: v~'tich tri_;>) ecr in the y plucac o Investi-
gation of thc~ rip}il c c,~::,p4ri~~n#. ~~eveuled tizut~ the ripple frec;uenoY
hatched the shaker frr~;uciyc;;-~ ~~ s~.-.usoida3~ vi7~ration of con-
att-nt 2 g rrns from 15 to 15t)O :ps .vAS app~.iLd in the x, y and
z planes. 'lie ri;~pte component, wus censtarat in the x and =
planes but peatced sharply rah: 'T(~U cpsa in they plane.
The acceleration tcast was conducted oa a t~eniaco ~iccelerato>r.
Oscillograph records .show no oUcurvable citarage in uny generator
parameter. 'Teat results are pi4tted in Z~.l~;o lS~,
5ho~:k test sp~acificationFz called for foear shocks in each
plane wi~fh can input fo.rc:c of 80 g in a oae hiU.iaecoad rise
tine witYe no requireme!~ts c~zs the rc to of clacay of the pulse.
Accelcx~oro$'k+~rs worn r~ocrtatod on the fixture such that the iopat
end responsQ raccelerations c:otilci be monitored. The shock test .
results are sic~i3ar to tkze ~riGrstiQn rea.ultsa ~tg~xin, the
y place dmta shc~ived ells 1r~Mt~eet ri~~ple compoa~ient and a decrease
in eff zc:irencyo 'fiaese data nrcc plotted i~a s~ ig. 17. The
electrical heating el.e~z~rxt9 u..~od to simulate the radioisotope
tailed in ttie tliirci shock in Lhe y pl~nne., fbq element wt~e
replaced ana the ~iaock i:c:~~;3 .~oiapl.eted,.
Four St~AY III l,ener+a'ko: A 1^-av~ pt~$sf~dl complete vibratiin,
accelera~~iora snci a:l-aock ~ t~W t ~, ~ If' no inet.ancQ liras them been a
failure of asa~r cor~,~o~L x~', ot:"~c,r ~:17.an th? e.lectrical heater.
Additiaraal ge:~=Ns?.:at r;~?~:: ~.e?c px,er;n~.ly uaiclea^aoiung te$t to ioprove
the statistical s~ig~n~.f Lra:xc;: ~a:~ ~iYCSO reca~xltso
ltllhat are the cie~ifixa .fer~turc,;t~ of SNRP III that make it
eu rugged? One iniFitt ~-~xpoo~ ~::~~uw floe springy-loaded conetructiod
could F~daclu~ttely cax5hion a?ada=il loAds provides the spring
reeonuacet, ~7re not excited sprint; resunance does not tut'n
out to be ~- c~rob.lern becrause in lies much 3ai~;hcr in frequency
rage than Lt~e vibration :lz-pute~ 1'ucking the lcsud telluride
elements f.ra powc~~~rc:d 1;4ira~=-i{ inc~uiati.on feeds to de~apen out any
ribratinxt on the Bart of tfYe ~rylemento, theaa$aIv'es~ All voids
in flits 3eraeratar are filled with poaldered b11ra-K so the
gon?rator sera be regarded as r~ pla$tic solid. 'Che axial support
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
~~
substituted for Po~-2100
?isht he a subject of coatc~r~n since it i~ maintained only by
sprinb pressure of the ;~nd:~v~.dual elements oc- the heat source
cylinder and the cocupres?~ed 6tiz~-:? domQSa This apprehension
is confir~aed to sam? e:: t.~:sa3, ht~cuuf:e of the consistently larger
effects in ~;he y glar~~~ tcs L~1
1'h? mechanisaa of Pa~vc ~^ r~utpfat decrease and !ts subsegn~tt
recovery has yat to be exnl.~ln~:d~ To do thin, consider in
detail the nature of the e.l~.ecL~: icril contact at the hot ~anotioa.
Under operating temt~err~turegt the springy; pressure causes Qlastio
tlo~v of the laced tQiZuride to t~roduce a partial mecbenicel bond
to the hot function shoe. ltie most lik?xy explenatfas of tee
ss+all decreaase in efficiency clur~ir~g ahoctc and vibration i?
that the contact resistance of tlhe partial bonded contact
incr.:ases :vith the simulated launch loads. After the test
cycle, heat end pressure again fuse ttte trot function contact
and the generator output recovers coapletely.
Although these testa indicate that SNAP III generators
will survive rocket 1?unch, additional te~ating is underw~y-
to demonstrate integrity of isotopic power sourcas in c+u? o!
launch abort apd in rePntryo E?'or space application., any 0!
several other isotopic fuels under study will probably be
t~udiatiaa douuge of the thermoelectric ~raterial by ~aaM
rays ia~ being investigated. ~{ couple si?ilar to those lv
SNr1F' III ha~ been irradiated for over 4130 tzr in Co-60 fields
of l06 x 10 r/'nr. A temperature gradient is beiag~waintained
in the test wad no change ire output has been observed.
In eumr~ary, although SNAI' IIx was Aesigrtod priaarily as
a proof of principle device, tt~e electric~-1 perforrane? data
and the vibration, acceleration and shock test results dis-
cussed indicAt~e the feasibility of using th? present geoerator
for extending the useful life or satellites,
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
~,' i
References
1. Ouru~ut, ~'., .lndereon, G.''., and Do114eier, E.R.
"3~_1;` III - i:lectricit~ lro~r Itadioauolides and ~erto-
eleatric Conversion", ~'~ucleonics, Vol. 17, ho. s3, 1859
Q. Rritts, It.~Y.~ "Design Paraaaeter? for Optia.ising the
Etliaiency o T6eraoeleotric Generators Utilis ng P-
tyype and N-type 1wAd Telluride", June 24, 1958,
dIF$ Tran,wot ions
3. Iotte, .t. R. ; "Sear ioonduotor Theraoelerents end Thera.o-
eleatrio Cooling", Intosearch, London
4. Bollpeier, %.:5.; "An Ele~aentar~- Uesiga Disoussion of
Thernoeleatria Generotion", Paper. No. CI' a9-S37, 19b9
6. ~ Glross, L.1~`. ; "Fnviroowental Test", Stia;' III Cenerntoe~,
~ 7~ID-P-2101
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
~, ~ ~i
List of Figures
to
20
3e
4.
5e
60
7a
80
90
100
llo
12~
130
140
150
16~
1?0
Mtist's concept of SN~~I' iII
Cross sectional drawing
P va IZL for air and bell far
0
TN and Pa va p curvQs
F,..Z and Pa curves {ti~ri.th X)
Po vs ItL for ttit;,h Parr and Gab
Ya vs ~ f ar Hibh Purr and Yacuna~
po vs ~ for La Y-vr and Goa
po vs t;L for Lo Pwr and Y~-cuum
Po va YIN for 3 (II ) B~
po va PlN for 3 {~?) ~~
p? vs PyN :"or air
Photo of Gcn~~'a~?or $n Fixture
Ec~u?~li~atiom cur~t0
~ vs Yib F`req
~.,~, vs Acceleration
.~, vs stlock
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
Fig. 1. Artist's Cor-cept oP 8~/1P-III (Ientr~-to~
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
J
C
C
J
2-Input Terminals
Solder Joint--Tin--Lead (6Q~+0)
Heat Source Cylinder
Thermocouple Elements
Insulating Washer
Hot Shoes
All Voida Filled Frith Ponder
Insulation
Rigid Insulation
Teimiral Strip
6 Thermocouple Terminals
2 Pover Output Terminals
i
i,
elation, 1/k in: Copper Tubing
Rigid Insulation
Insulating Pad
Cover
Ad.~ustment Scree
Spring
Cold Junction Socket
Insulating Sleeve
Element Cap
Cold Junction Housing
Heat Source Electric Cartrid?e
?i~. 2. Cress ~$ieticoal rises vt ~AP~-ffi
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
3.5
3.0
1.5
0.5
2 3 k
Iad Resieteaoe (obw j
Rooms Asbieat
(Radiator Temperature - 175' F
Poloaiu~ Thermal Input--50.2 w
Fib. 3. Poser Output vs lrowd Resistaaoe !tom 8to~rd !b?3~1i0 lrwi+ed ~AP?IIi
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 800
Polonium Thermal Input--36
Cold Junction Temperature ..220
Dome Insulation--fire brick
Element Insulation-teynthet
O.OtZ
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0.1
1 LO
Internal (3etress~tar Pre aau~r+e (a Hg )~
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Paver Out (v)
I.70
1.60 ( ~~
~_ ,
1.50
1.30
0.90
0.80
.70
 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
t
~~ ~
~.S ~
k.O
3.5
3.0
1.5
0.5
Fig. 5. Volt -Ampere f;r~d PvWer Output Curves Por Second
Po-210 Fueled SNAP-III
~ ~ ~
0.5 ~..0 1.5
Output Current (amperes)
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
3.2
2.8
2.k
5?.S
0.8
0.4
Bell Jar
Fig. 6. Pacer Oirt v~ Load Aesistaaoe Pa~tr~retric in PaRr h-
8~-221 1-tiied Yit.h Atannot~rl+e Be--15K H)
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
~J
3.2
2.8
2.4
2.0
1.6
0.8
0.4
4 6
Load Reeistaace (oh4aa )
FiQ. 7. .Fewer Out vs Losd Reei~tance Parratsia in Paver ~n
(SlIAP?III Evacuated)
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
,. ~~
1.4
0.6
0.4
45.9
0 2 4 6 g io.~~~
Load Red Canoe (ohu)
Fig. 8. Poorer Out re Load Raaiatatyoe Para~etria in Powr Io (Loy
PaMer 811~AP-III With At~ospbere o! 95~ Aw..;~, ~?
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
~~
1.6
l.b~
0.6~
0.4~
~?3
(1.ar Pv~rar aIAP?III ~rww-
- -,
4 6
I.oaA Reoletsao~ (os~s
tig. 9. Pw~er Out va Loud Resi~tatws Pa:"~rtsfs i~ hw~r Ia
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
__~ U I
2.8 r-
2.4j
0.8
0.4
3~
Paver In (w)
40
50 60
Fig. 10. Power Out ?s Pa-er In fflr 8lfAP-III gvacuattd and Oas d'l.llnd
Conditions
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
? `/
1,G
O.k
l.k
10 15
1
- _,,,..
25
Power In (w)
J
~-g
Fig. 11. Power Out va P~ryrar 7., ~,,., r.... ~____ w ~~
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 r Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 r: CIA-RDP78-03424A001200080003-9
~ \~
j ____._
~
!
`
~
Ko~!m A.r,:k ~.,.,
~
i
~
i
~ ~
I
~ 2 _~
.~
2A
I
In
~
I
!
--
-
_.
i
~.
I
'
I
~--
I
f
~-_
I
,
1
___---
-'
I
;--------t
--
-~
~
_-
{
Power In (w)
i
Fig. 12. Power Out va Power In for Evacuated BNAP-III
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
C_J
100 1000
(cps)
Tig. lk. Final EgnslizaLiCn Curve--Y P1atx Modsl 177A t~li0yat Sbaker
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
e~z
v
C
O
0
Poat and Pre-Test Zrest 2
T
20 30
Tame (mia)
Tg =800 ? F
T~ =120 ? F
Pi = 60 Watts
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 Declassified in Part - Sanitized Copy Approved for Release 2012/03/08: CIA-RDP78-03424A001200080003-9
TH = 826 ? F
T~ = 123 ? F
Pi = 59.6 watts
4
T
IO
,-
15
Tss (sin)
T
25
~"ii- 16, Aao~Lrratian ~+est -.~ Y !'Lmr
35 40
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 Declassified in Part -Sanitized Copy Approved for Release 2012/03/08 :CIA-RDP78-03424A001200080003-9
3.0 ~
~ ~ -test
gig. iT. S~oc]~ Test ' e~+-aI Y Plsae
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