Second International Conference on Thermionic Electrical Power Generation EUR 4210 = Deuxieme Conference Internationale sur la Production Thermo Ionique d'Energie Electrique EUR 4210

s .

•

EUROPEAN ATOMIC ENERGY COMMUNITY

COMMUNAUTE EUROPEENNE DE L'ENERGIE ATOMIQUE

EURATOM

SECOND INTERNATIONAL CONFERENCE ON

THERMIONIC ELECTRICAL POWER GENERATION

Stresa, Italy - May 27-31, 1968

DEUXIEME CONFERENCE INTERNATIONALE

SUR LA PRODUCTION

THERMO-IONIQUE D'ENERGIE ELECTRIQUE

Stresa, Italie - 27-31 mai 1968

under the auspices of the

European Nuclear Energy Agency - OECD

organized by Euratom - Joint Nuclear Research Centre, Ispra (Italy)

sous l'égide de

l'Agence Européenne pour l'Energie Nucléaire - O.C.D.E.

organisée par Euratom - Centre Commun de Recherche Nucléaire, Ispra (Italie)

UL

WVWv

Published by the Euratom Genter for Information and Documentation Publié par le Centre d'Information et de Documentation

LEGAL NOTICE

The Commission of the European Communities and its departments are not responsible for the use which could be made of the following

information.

3

-PROGRAM COMMITTEE

D r . H. Neu (Chairman)

Dr. L. Agnew

M r . B. Devin

D r . G. Hatsopoulos

Dr. R. Langpape

Dr. J. My att

I s p r a Joint R e s e a r c h Centre Establishment,

E u r a t o m , I s p r a ,

Italy-International Atomic Energy Agency,

Vienna, A u s t r i a

C o m m i s s a r i a t à l ' E n e r g i e Atomique,

Saclay, F r a n c e

T h e r m o E l e c t r o n C o r p . ,

Waltham, M a s s a c h u s e t t s , United States

Brown, Boveri u. C i e . ,

Mannheim, Germany

F o r e w o r d

The first "International Conference on Thermionic E l e c t r i c a l Power Gene­

ration" was held in London, in October 1965. This second conference about

two and a half y e a r s after the London conference gives evidence of the r e ­

markable p r o g r e s s in thermionic energy conversion which has taken place

since that t i m e . The strong participation of scientists from the USSR has

for the first time enabled an intensive exchange of information between

E a s t and West and has given the opportunity for further p e r s o n a l contacts

between the Soviet scientists and their Western colleagues.

The proceedings include all p a p e r s which have been accepted or invited by

the P r o g r a m Committee and submitted to the conference S e c r e t a r i a t .

P a p e r s a r e reproduced in their original form as submitted by the a u t h o r s .

In addition, the proceedings include a contribution "Survey of E x p e r i m e n t a l

Work in the USSR" by Dr. Y. A. DANILOV of the Moscow Aviation Institute,

(Consultant of USSR State Committee for the Utilization of Atomic Energy)

which was invited during the conference, and two introductions for the panel

discussion by Dr. Gerald F . TAPE, Commissioner of the USAEC and

Dr. Y.A. DANILOV.

The discussions which took place in the conference, a r e attached at the end

of the respective p a p e r s , with the exception of Session D where the d i s c u s ­

sions a r e placed at the end of the Session.

I am grateful for the cooperation of the contributors who submitted their

text early enough for publication in these proceedings. Unfortunately, no

contributions or corrections of t r a n s c r i p t s could be retained, which a r r i v e d

later than August 8th. This deadline has been fixed in o r d e r to enable quick

distribution of the proceedings, which is in the i n t e r e s t of all.

F u r t h e r , I wish to thank M r s . Dorpema of I s p r a for providing the t r a n s ­

cripts of the d i s c u s s i o n s , D r . L. K. Hansen for his great help in editing

these and M r s . Stalpaert from the E u r a t o m Information and Documentation

Centre in B r u s s e l s for managing the publication of the proceedings.

7

-C O N T E N T S

P a g e

O P E N I N G SESSION

W e l c o m e on behalf of the s p o n s o r i n g o r g a n i z a t i o n ,

by M r . L . B O X E R , E u r o p e a n N u c l e a r E n e r g y A g e n c y . 21 W e l c o m e on behalf of the o r g a n i z i n g i n s t i t u t i o n ,

by P r o f . H. K R A M E R S , E u r a t o m R e s e a r c h E s t a b l i s h m e n t , I s p r a . 22

I n t r o d u c t i o n to the C o n f e r e n c e ,

by D r . H. N E U , E u r a t o m R e s e a r c h E s t a b l i s h m e n t , I s p r a . 24

S E S S I O N A " C O N V E R T E R P E R F O R M A N C E "

C h a i r m a n : D r . R. W. P I D D V i c e - C h a i r m a n : D r . R. P R U S C H E K

A - l S u m m a r y of A p p l i e d R e s e a r c h P r o g r a m in T h e r m i o n i c C o n v e r ­ s i o n d u r i n g R e c e n t Y e a r s

F . R U F E H , D. L I E B and L, v a n S O M E R E N , T h e r m o E l e c t r o r

C o r p o r a t i o n , W a l t h a m , M a s s a c h u s e t t s , USA 29 A 2 C h a r a c t e r i s t i c s of a T h e r m i o n i c C o n v e r t e r with a C h l o r i d e

-V a p o r - D e p o s i t e d T u n g s t e n E m i t t e r and a N i c k e l C o l l e c t o r V. C. WILSON, G e n e r a l E l e c t r i c R e s e a r c h and D e v e l o p m e n t

C e n t e r , S c h e n e c t a d y , New Y o r k , USA 45 A - 3 E s s a i s d ' u n c o n v e r t i s s e u r du type n u c l é a i r e m u n i d ' u n r é s e r ­

v o i r de c é s i u m à a d s o r p t i o n

P h . D E F R A N O U L D , L a b o r a t o i r e s de R e c h e r c h e s G é n é r a l e s ,

C o m p a g n i e F r a n ç a i s e T h o m s o n H o u s t o n , F r a n c e 51 A - 4 E x a m e n d e s c o u c h e s r é f r a c t a i r e s p y r o l y t i q u e s au m o y e n du

m i c r o s c o p e é l e c t r o n i q u e s e c o n d a i r e à b a l a y a g e

G. B L E T et O. C A H E N , L a b o r a t o i r e s de R e c h e r c h e s G é n é ­

r a l e s , C o m p a g n i e F r a n ç a i s e T h o m s o n H o u s t o n , F r a n c e 57

A - 5 T h e r m i o n i c C o n v e r t e r T e c h n o l o g y

P . R O U K L O V E , J e t P r o p u l s i o n L a b o r a t o r y , P a s a d e n a , C a l i ­

f o r n i a , USA 61

A - 7 High P r e s s u r e C e s i u m T h e r m i o n i c C o n v e r t e r with a Cold R e ­ gion

B . S T E F A N O V , L. ZARCOVA, B u l g a r i a n A c a d e m y of S c i e n ­

g a g e M l l e . L A T O U C H E ­ H A L L E , L a b o r a t o i r e s de R e c h e r c h e s

G é n é r a l e s , C o m p a g n i e F r a n ç a i s e T h o m s o n H o u s t o n , F r a n c e 81 A ­ 9 A r c ­ M o d e T h e r m i o n i c C o n v e r t e r P e r f o r m a n c e : M e a s u r e ­

m e n t s a n d I n t e r p r e t a t i o n

A . E . C A M P B E L L , J r . a n d Α . Ο. J E N S E N , E l e c t r o ­ O p t i c a l

S y s t e m s , P a s a d e n a , C a l i f o r n i a , USA 87 A ­ 1 0 T e c h n o l o g i e d e s c o n v e r t i s s e u r s t h e r m o ­ i o n i q u e s p l a n s et

c y l i n d r i q u e s

A . M. S H R O F F , C o m p a g n i e G é n é r a l e de T é l é g r a p h i e s a n s F i l , C e n t r e de P h y s i q u e E l e c t r o n i q u e et C o r p u s c u l a i r e , C o r b e ­

v i l l e , O r s a y , F r a n c e 103 A ­ l l B i l a n d e s é t u d e s de d u r é e de v i e d e s c o n v e r t i s s e u r s t h e r m o ­

i o n i q u e s en l a b o r a t o i r e

J . B L I A U X , M. C L E M O T , J . P . DURAND e t B . G A Y T E , C e n t r e d ' E t u d e s N u c l é a i r e s de S a c l a y , F r a n c e 113 A ­ 1 3 I n v e s t i g a t i o n of a N e ­ Α T h e r m i o n i c G e n e r a t o r

M . B A C A L , M . C R I S T E S C U a n d C. V O C I , I n s t i t u t e f o r A t o m i c

P h y s i c s , B u c h a r e s t , R u m a n i a 125 A ­ 1 4 M o d u l e T h e r m o ­ i o n i q u e N u c l é a i r e t o u t ­ m é t a l

Β . D E V I N , J . P . D U R A N D , P . R A G O T , C e n t r e d ' E t u d e s N u c l é ­

a i r e s de S a c l a y , F r a n c e 133 SESSION Β " I N T E G R A T E D S Y S T E M S "

C h a i r m a n : M r . R. C. HOWARD V i c e ­ C h a i r m a n : D r . S . V . RYABIKOV

B ­ l T h e I n ­ C o r e T h e r m i o n i c R e a c t o r a s a S p a c e P o w e r S o u r c e H. A N D R A E , D. BUDNICK, F . GROSS, W. J A H N S , Κ. J A N ­ N E R a n d A . J E S T E R , B r o w n , B o v e r i u . C i e A G . , M a n n h e i m ;

I n t e r a t o m , B e n s b e r g ; S i e m e n s A G . , E r l a n g e n , G e r m a n y 143 B ­ 2 R e s u l t s of S t u d i e s on V a r i o u s F a s t a n d T h e r m a l T h e r m i o n i c

R e a c t o r S y s t e m s

R. P R U S C H E K , S. D A G B J A R T S S O N , D . E M E N D Ö R F E R , M. G R O L L , W. HAUG, B . R Ö H R B O R N , Η. U N G E R a n d E . W O L F , I n s t i t u t für K e r n e n e r g e t i k , U n i v e r s i t ä t S t u t t g a r t ,

G e r m a n y 157

B ­ 3 M u l t i m e g a w a t t T h e r m i o n i c R e a c t o r S y s t e m s f o r S p a c e A p p l i ­

P a g e .

C D . SAWYER, P . R. HILL and D. R. WILKINS, V a l l e c i t o s

N u c l e a r C e n t e r , G e n e r a l E l e c t r i c Co. , P l e a s a n t o n , C a l i ­

fornia, USA

171

B­4

T h e r m i o n i c E l e c t r i c P r o p u l s i o n S y s t e m C h a r a c t e r i s t i c s

and Capabilities

W . A . RANKEN and E . W. SALMI, Los A l a m o s Scientific L a ­

b o r a t o r y , U n i v e r s i t y of California, Los A l a m o s , New M e x i ­

co, USA

185

B ­ 5

T h e r m i o n i c R e a c t o r s for E l e c t r i c P r o p u l s i o n ­ P a r a m e t r i c

Studies

W . G . HOMEYER, C.A

HEATH and A, J, GIETZEN, Gulf

G e n e r a l Atomic Inc. , San Diego, California, USA

201

B­6

E x t e r n a l ­ F u e l T h e r m i o n i c R e a c t o r s

M. J. ABBATE, C. L. EISEN, Β. RAAB and Α. SCHOCK,

Republic Aviation Division of F a i r c h i l d H i l l e r C o r p o r a t i o n ,

F a r m i n g d a l e , New York, USA

221

B­7

Uninsulated I n ­ C o r e T h e r m i o n i c Diode Concept

J. P . DAVIS, H. G. GRÖNROOS, J e t P r o p u l s i o n L a b o r a t o r y ,

P a s a d e n a , California, USA

237

B­8

A Heat P i p e T h e r m i o n i c R e a c t o r Concept

P . FIEBELMANN, H. NEU and C. RINALDINI, E u r a t o m Joint

R e s e a r c h C e n t e r , I s p r a , Italy

243

B­9

O u t ­ o f ­ C o r e T h e r m i o n i c Space P o w e r

W . E . LOEWE, L a w r e n c e Radiation L a b o r a t o r y , U n i v e r s i t y of

California, L i v e r m o r e , California, USA

263

B­10 Stability and C o n t r o l C o n s i d e r a t i o n s for T h e r m i o n i c R e a c t o r s .

H. G. GRÖNROOS and J..P* DAVIS, J e t P r o p u l s i o n L a b o r a t o r y ,

P a s a d e n a , California, USA

273

B ­ l i Development of a 100 Watt (e) Isotope T h e r m i o n i c E l e c t r i c a l

P o w e r Module

E . W. WILLIAMS, G e n e r a l E l e c t r i c M i s s i l e and Space Divi­

sion, Valley F o r g e , P e n n . , USA and R. C. HOWARD, T h e r m o

E l e c t r o n C o r p o r a t i o n , Waltham, M a s s a c h u s e t t s , USA

281

B­12 S N A P ­ 1 3 , G e n e r a t o r Development P r o g r a m

J. B. DUNLAY and R. C. HOWARD, T h e r m o E l e c t r o n C o r p o r a ­

tion, Waltham, M a s s a c h u s e t t s , USA

297

B­13 Design and C h a r a c t e r i s t i c s of an Actinium Fueled T h e r m i o n i c

G e n e r a t o r

A. DE TROYER and E . NEVE de MEVERGNIES, Union M i n i e r e ,

B r u s s e l s , Belgium; M. J. BRABERS, P . DE JONGHE, C e n t r e

d'Etude de l ' E n e r g i e N u c l é a i r e , Mol­Donk, Belgium; G. GAM­

M E L , F . GROSS , M. F . KOSKINEN and R. LANGPAPE, Brown

10

-B - 1 5 A M i n i a t u r e A t o m i c -B a t t e r y -B a s e d on T h e r m i o n i c C o n v e r ­ sion

P a g e

N. S. RASOR, K . A . G A S P E R and J . G. D e S T E E S E , M c D o n ­ n e l l D o u g l a s C o r p o r a t i o n , Donald W. Douglas L a b o r a t o r i e s ,

R i c h l a n d , W a s h i n g t o n , USA 337 B - 1 6 T h e r m i o n i c E l e c t r i c a l P o w e r G e n e r a t i o n f r o m R e - E n t r y

P l a s m a s

K . J . TOURYAN and M. M. S L U Y T E R , S a n d i a L a b o r a t o r y ,

A l b u q u e r q u e , New M e x i c o , USA 345

SESSION C " I N - P I L E T E S T I N G "

C h a i r m a n : M r . B . DEVIN V i c e - C h a i r m a n : D r . Yu. S. YURIEV

C - l I n - R e a c t o r T h e r m i o n i c C o n v e r t e r T e s t i n g E x p e r i e n c e at G e ­ n e r a l E l e c t r i c

J . E . v a n HOOMISSEN and D. J . HOTSLAG, V a l l e c i t o s N u c l e a r

C e n t e r , G e n e r a l E l e c t r i c C o . , P l e a s a n t o n , C a l i f o r n i a , USA 353 C - 2 C o n v e r t e r S D - 4 D e s i g n and S u m m a r y of T e s t R e s u l t s

R. C. HOWARD and J. B . DUNLAY, T h e r m o E l e c t r o n C o r p o ­

r a t i o n , W a l t h a m , M a s s a c h u s e t t s , USA 365 C - 3 L o n g - T e r m O p e r a t i o n s of I n - P i l e and O u t - o f - P i l e T h e r m i o n i c

C o n v e r t e r s

J . W . H O L L A N D , M. K. Y A T E S , D . E . S C H W A R Z E R and J .

KAY, Gulf G e n e r a l A t o m i c I n c . , S a n D i e g o , C a l i f o r n i a , USA 385

C - 4 R e t e n t i o n of F i s s i o n G a s e s in the U O? P h a s e of MoUO

-C e r m e t s I r r a d i a t e d at High T e m p e r a t u r e s .

W . A . RANKEN, M . C . CHANEY and A . J. P A T R I C K , L o s A l a ­ m o s Scientific L a b o r a t o r y , U n i v e r s i t y of C a l i f o r n i a , L o s A l a ­

m o s , New M e x i c o , USA 411 C - 5 E x p é r i e n c e s de c o n v e r s i o n t h e r m o - i o n i q u e " S I R E N E " en p i l e

et e x a m e n a p r è s i r r a d i a t i o n du c o n v e r t i s s e u r " S I R E N E 3 0 2 " J . BLIAUX, M. C L E M O T , B . DEVIN et P . DUMAS, C e n t r e

d ' E t u d e s N u c l é a i r e s de S a c l a y , F r a n c e 421 C - 6 L a b o r a t o r y L i f e - T e s t and I n - P i l e I r r a d i a t i o n S t u d i e s of C y l i n ­

d r i c a l T h e r m i o n i c C o n v e r t e r s

A . J E S T E R , F . GROSS, H. HOLICK, R. K R A P F and R. Z Ö L ­ L E R , B r o w n , B o v e r i u. C i e , A G . , M a n n h e i m , C e n t r a l R e ­

s e a r c h L a b o r a t o r y , H e i d e l b e r g , G e r m a n y 437 C - 7 P o s t - I r r a d i a t i o n I n v e s t i g a t i o n s of U O _ - F u e l e d , T h e r m i o n i c

E m i t t e r s

F . GROSS and R. Z Ö L L E R , B r o w n , B o v e r i u. C i e . A G . , M a n n h e i m , C e n t r a l R e s e a r c h L a b o r a t o r y , H e i d e l b e r g , G e r ­

11

-Page_

SESSION D "HEAT PIPE SYSTEMS"

Chairman : Dr. G. M. GROVER

Vice-Chairman : Dr. C.A. BUSSE

Invited P a p e r : Dr. C.A. BUSSE "Heat Pipe R e s e a r c h in E u r o p e " 461

D - l Advances in Heat Pipe Technology

G. M. GROVER, J. E. KEMME and E . S. KEDDY, Los Ala­

mos Scientific Laboratory, University of California, Los

Alamos, New Mexico, USA 477

D-2 High T e m p e r a t u r e Lithium Heat Pipes

C.A. BUSSE, F . GEIGER and H. STRUB, E u r a t o m Joint R e ­

s e a r c h Center, I s p r a , Italy; M. PÖTZSCHKE and G. KRAFT,

Metallgesellschaft AG. , F r a n k f u r t / M . , Germany 495

D-3 P r e s s u r e Balance and Maximum P o w e r Density at the E v a p o ­

ration Gained from Heat Pipe E x p e r i m e n t s

F . REISS and K. SCHRETZMANN, Institut für Neutronenphy­

sik und Reaktortechnik, Kernforschungszentrum K a r l s r u h e ,

Germany 507

D-4 Détermination théorique et expérimentale de la puissance t h e r ­

mique limite t r a n s f é r é e p a r des caloducs à sodium

E . SCHMIDT et R. SEMERIA, Centre d'Etudes Nucléaires de

Grenoble, Grenoble, F r a n c e 515

D-5 Heat Pipe Design Theory

E. van ANDEL, E u r a t o m Joint R e s e a r c h Center, I s p r a , Italy 529

D-6 Liquid-Vapor Interaction and Evaporation in Heat Pipes

A. BAHR, E. BURCK, W. HUFSCHMIDT, E u r a t o m Joint R e ­

s e a r c h Center, I s p r a , Italy 543

D-7 Résultats p r é l i m i n a i r e s d'une étude sur les caloducs à haute

t e m p é r a t u r e

M. ARMAND et A. M. SHROFF, Compagnie Générale de T é l é ­

graphie sans Fil, Groupement Scientifique et Technique, Do­

maine de Corbeville, Orsay, F r a n c e 557

Discussions of P a p e r s Session D

SESSION E "MATERIALS"

Chairman : Dr. A. M. SHROFF

Vice-Chairman: Dr. Yu. L. DANILOV

E - l Chemical Vapor-Deposition of Tungsten E m i t t e r s of (110) P r e ­

ferred Crystal Orientation

R.G. HUDSON, T. TA GAMI and L. YANG, Gulf General Ato­

mic Inc. , San Diego, California, USA 565

E-2 Fuel and Fission Product T r a n s p o r t Through Chemically

Vapor-Deposited Fluoride Tungsten

12

P a g e D i e g o , C a l i f o r n i a , USA

E ­ 3 D e p o t p a r d é c o m p o s i t i o n t h e r m i q u e e n p h a s e v a p e u r de t u n g s t è n e , r h é n i u m et n i o b i u m et d ' a l l i a g e n i o b i u m t u n g ­ s t è n e

A . M . S H R O F F , C o m p a g n i e G é n é r a l e de T é l é g r a p h i e s a n s F i l , G r o u p e m e n t S c i e n t i f i q u e et T e c h n i q u e , D o m a i n e de C o r ­

b e v i l l e , O r s a y , F r a n c e 589 E ­ 4 D e p o s i t i o n of T u n g s t e n ­ L a y e r s on M o l y b d e n u m a n d I n t e r ­

d i f f u s i o n

M . P E E H S a n d H . S T E H L E , S i e m e n s A G . , Z e n t r a l e E n t ­

w i c k l u n g und F o r s c h u n g , E r l a n g e n , G e r m a n y 603 E ­ 5 M e t a l ­ T o ­ C e r a m i c S e a l s f o r T h e r m i o n i c C o n v e r t e r s

C . M . C A P P E L L E T T I a n d C . A . B U S S E , E u r a t o m J o i n t R e ­ s e a r c h C e n t e r , I s p r a , I t a l y ; Ε . Α . D Ö R R E , F e l d m ü h l e A G . ,

P l o c h i n g e n , G e r m a n y 613 E ­ 6 S c e l l e m e n t s c é r a m i q u e ­ m é t a l

A . M . S H R O F F e t S. E S N A U D , C o m p a g n i e G é n é r a l e de T é l é ­ g r a p h i e s a n s F i l , G r o u p e m e n t S c i e n t i f i q u e e t T e c h n i q u e , D o ­

m a i n e d e C o r b e v i l l e , O r s a y , F r a n c e 633 E ­ 7 M u l t i ­ F o i l T h e r m a l I n s u l a t i o n U s i n g O x i d e P a r t i c l e L a y e r

S e p a r a t i o n

J . B . D U N L A Y , T h e r m o E l e c t r o n C o r p o r a t i o n , W a l t h a m , M a s ­

s a c h u s e t t s , USA 639

E ­ 8 A S p e c i a l T e c h n i q u e f o r M a n u f a c t u r i n g I n s u l a t i n g C o l l e c t o r M u l t i l a y e r T u b e s .

M . P E E H S , H . S C H Ö R N E R a n d H. S T E H L E , S i e m e n s A G . ,

Z e n t r a l e E n t w i c k l u n g und F o r s c h u n g , E r l a n g e n , G e r m a n y 647 E ­ 9 I n s u l a t i n g M a t e r i a l s of T h e r m o ­ E m i s s i o n C o n v e r t e r s

R . G . B E L Y A N I N A , V . L . B O N D A R E N K O , A . A . B O R I S O V A , I. N . G O R E L O V , Yu. V. DVINAKIKH, I. P . Z A S O R I N , J . I . I E V L E V A , A . A . K O R O L Y O V , A . D . KUNKINA, N . P . M A X I ­ MOV, B . A . M A L Y K H , V. P . S H A R O V , I . M . S A R A T O V a n d D . D . Y A K O V L E V A , I n s t i t u t e of P h y s i c s a n d P o w e r E n g i n e e r ­

i n g , O b n i n s k , USSR 6 55

E ­ 1 0 On t h e E f f e c t of B a r i u m on C o n v e r t e r M a t e r i a l s

R. H E N N E , D e u t s c h e V e r s u c h s a n s t a l t für L u f t ­ und R a u m ­ f a h r t , e . V . , I n s t i t u t für E n e r g i e w a n d l u n g u n d E l e k t r i s c h e

A n t r i e b e , S t u t t g a r t ­ V a i h i n g e n , G e r m a n y 671 E ­ l l T h e r m a l C o n t a c t R e s i s t a n c e i n C y l i n d r i c a l E l e m e n t s i n T h e r m ­

i o n i c E n e r g y C o n v e r t e r s

Y u . I . D A N I L O V , V. K. KOSHKIN, T . V . M I K H A I L O V A , Yu. S.

M I K H E E V a n d S. A . O R L I N , USSR 683 E ­ 1 2 U t i l i s a t i o n d e s a l l i a g e s d e t i t a n e en c o n v e r s i o n t h e r m o ­ i o n i q u e .

­ 13 ­

P a g e

N u c l é a i r e s de Saclay, et E . R. JOSSO, Société M é t a l l u r ­

gique d'Imphy, F r a n c e

699

E ­ 1 4 A Low Swelling, Oxide F u e l e d T h e r m i o n i c E m i t t e r

H. HÜBNER, K. JANNER, M. PEEHS and H. S T E H L E ,

S i e m e n s AG. , Z e n t r a l e Entwicklung und F o r s c h u n g , E r ­

langen, G e r m a n y

711

E ­ 1 5 T h e r m a l R e s i s t a n c e of Multilayer C y l i n d r i c a l E l e m e n t s in

the T h e r m i o n i c C o n v e r t e r s

E . S. A. ARKIN, S . F . KUKUSHKIN, H . A . MURINSON, B. G.

OGLOBIN, P . Ζ. CHEREPANOV, V. S. CHEKHOVICH, The

A c a d e m y of S c i e n c e s , Moscow, USSR

721

E ­ 1 6 High T e m p e r a t u r e Compatibility of R e f r a c t o r y Metals in Con­

t a c t with R e f r a c t o r y M a t e r i a l s

J. J. HUET and J . VANGEEL, C e n t r e d'Etude de L ' E n e r g i e

N u c l é a i r e , Mol, Belgium

731

E ­ 1 7 Etude de la soudure p a r diffusion du molybdène

G. FUSTIE, B. JACOUIN, Société Bocuze, L e s E c h e t s ,

F r a n c e , et J. P . DURAND, M. CLEMOT, C e n t r e d ' E t u d e s

N u c l é a i r e s de Saclay, F r a n c e

749

E ­ 1 8 Investigation of Diffusion I n t e r a c t i o n and S t r u c t u r a l Stability

of Cathode M a t e r i a l

V.N. BYKOV, L. V. PAVLINOV, Yu.A. GORBAN, M. I.

ZAKHAROVA, A.A. KOROLEV, V.A. M A L Y K H , I. P. M U K ­

HIN, A. I. NAKONECHNIKOV, B.A. NEVZOROV, A.V. FRO­

LOV, A.S. SHA

TALIN, USSR

761

E ­ 1 9 C e r m e t s a s M a t e r i a l for T h e r m i o n i c E m i t t e r s

D. SCHMIDT, Deutsche V e r s u c h s a n s t a l t für Luft­ und R a u m ­

fahrt e . V . ; G. ONDRACEK, K e r n f o r s c h u n g s z e n t r u m , K a r l s ­

ruhe und E . GEBHARDT, M a x ­ P l a n c k ­ I n s t i t u t für M e t a l l f o r ­

schung, Stuttgart, G e r m a n y

773

E ­ 2 0 C e s i u m Sorption in M a t e r i a l s for T h e r m i o n i c C o n v e r t e r s

M. K. YATES and G. O. F I T Z P A T R I C K , Gulf G e n e r a l A t o m i c

Inc. , San Diego, California, USA

783

E ­ 2 1 Sur l e s applications aux études des é m e t t e u r s t h e r m o ­ i o n i q u e s

d'un nouveau réactif du molybdène

R. HASSON, C e n t r e d ' E t u d e s N u c l é a i r e s de Saclay, F r a n c e

795

SESSION F "CONVERTER AND SYSTEM DESIGN ANALYSIS"

C h a i r m a n

: D r . J. E . van HOOMISSEN

V i c e ­ C h a i r m a n : D r . G. M. GRAZIANOV

F ­ l

T h e o r y of T h e r m i o n i c C o n v e r t e r Operation with Applications

to T h e r m i o n i c R e a c t o r A n a l y s i s

D. R. WILKINS, C. D. SAWYER and P . R. HILL, G e n e r a l

14

F - 3 C o m p a r i s o n of M e t h o d s for C a l c u l a t i n g R a d i a t i v e Heat T r a n s f e r

P a g e

A . SCHOCK and M. J. A B B A T E , R e p u b l i c A v i a t i o n D i v i s i o n

of F a i r c h i l d H i l l e r C o r p o r a t i o n , F a r m i n g d a l e , New Y o r k , USA 813 F 4 M e t h o d s of C a l c u l a t i o n and O p t i m i z a t i o n of T h e r m i o n i c E l e c

-t r o g e n e r a -t i n g E l e m e n -t s

I. S. MOSEVITSKY, K u r c h a t o v I n s t i t u t e of A t o m i c E n e r g y ,

M o s c o w , USSR 821 F - 5 T h e r m i o n i c C o n v e r t e r E l e c t r i c a l C h a r a c t e r i s t i c s with M a t r i x

C i r c u i t C o n n e c t i o n s

G . I . GUTSHIN, A. P . KOLMAKOV, E . B . P E R E S L A V T S E V , V. Ya. P U P K O , V . l . SUBBOTIN, G . M . CHERNUKHINA and Yu. S. YURIEV, I n s t i t u t e of P h y s i c s and P o w e r E n g i n e e r i n g ,

O b n i n s k , USSR 833 F - 7 T h e o r e t i c a l Study of T r a n s i e n t T h e r m a l C o n d i t i o n s D u r i n g the

S t a r t - u p of a T h e r m i o n i c C o n v e r t e r

E . S . A . ARKIN, A . N . L U P P O V , H . A . MURINSON, B . G. O G L O B L I N , P . Z . C H E R E P A N O V , The A c a d e m y of S c i e n c e s ,

M o s c o w , USSR 84 5

F - 1 0 F a i l u r e M o d e l s and R e l i a b i l i t y A n a l y s i s of T h e r m i o n i c C o n v e r t e r C o m p o n e n t P a r t s

B. B. DIAKOV, A c a d e m y of S c i e n c e s of the USSR, A. F . Yoffe

P h y s i c a l T e c h n i c a l I n s t i t u t e , L e n i n g r a d , USSR 853

F - 1 2 A n a l y s i s and O p t i m i z a t i o n o f ' F u l l - L e n g t h " D i o d e s

A . SCHOCK, R e p u b l i c A v i a t i o n D i v i s i o n of F a i r c h i l d H i l l e r

C o r p o r a t i o n , F a r m i n g d a l e , New Y o r k , USA 86 5

SESSION G " T H E O R Y O F C O N V E R T E R S "

C h a i r m a n : D r . J . BOHDANSKY V i c e - C h a i r m a n : D r . Ch. WARNER

Invited P a p e r : C o m m e n t s on P l a s m a T h e o r i e s for C e s i u m D i o d e s

by G . N . H A T S O P O U L O S 881 G - l T h e Spacing Effect in the Ignited Mode Diode

L . K. HANSEN, I n s t i t u t e for T h e o r e t i c a l P h y s i c s , R u h r - U n i ­

v e r s i t y , B o c h u m , G e r m a n y 899 G-2 T h e o r y of the L o w - V o l t a g e A r c in the C e s i u m T h e r m i o n i c C o n ­

v e r t e r

E . B . SONIN, I n s t i t u t e of S e m i c o n d u c t o r s , A c a d e m y of S c i e n c e s

L e n i n g r a d , USSR 911

G-4 The V o l t a g e D r o p of the I g n i t e d Mode a s a F u n c t i o n of C u r r e n t D e n s i t y

B . SAGGAU and H. S T R E C K E R , I n s t i t u t für G a s e n t l a d u n g s

-t e c h n i k und P h o -t o e l e k -t r o n i k , U n i v e r s i -t ä -t S -t u -t -t g a r -t , G e r m a n y 923 G - 5 T h e o r e t i c a l C o n s i d e r a t i o n s of the Ignited Mode

C. WARNER, A t o m i c s I n t e r n a t i o n a l , C a n o g a P a r k , C a l i f o r n i a ,

15

-Page

G-7 On Low-Voltage A r c in Cesium Vapor

I. P . STAKHANOV and I . I . KASSIKOV, Institute of Physics

and Power Engineering, Obninsk, USSR 945

G-8 A Coherent E l e m e n t a r y Description of Thermionic Converter

Phenomenology (manuscript not received)

N. S. RASOR, Donald W. Douglas L a b o r a t o r i e s , McDonnell

Douglas Corporation, Richland, Washington, USA

G-9 Two Types of Potential Distribution in Collisionless Mode

of Thermionic Converter Operation in the P r e s e n c e of T r a n s ­

v e r s e Magnetic Field

A. ENDER, Academy of Sciences of the USSR, A. F . Yoffe

Physical Technical Institute, Leningrad, USSR 957

G - l l Effect of Cesium P r e s s u r e on Thermionic Stability

A. SCHOCK, Republic Aviation Division of F a i r c h i l d Hiller

Corporation, F a r m i n g d a l e , New York, USA 969

G-12 On the Theory of Electrode L a y e r of P l a s m a

I. P . STAKHANOV and P . P . SCHERBININ, Institute of P h y s i c s

and Power Engineering, Obninsk, USSR 979

SESSION H "CONVERTER PERFORMANCE ANALYSIS"

Chairman : Prof. P . D . DUNN

V i c e - C h a i r m a n : Mr. P . ROUKLOVE

H-2 C a l o r i m e t r i e M e a s u r e m e n t s with a Heat Pipe Thermionic Con­

v e r t e r

J. BOHDANSKY and E . van ANDEL, E u r a t o m Joint R e s e a r c h

Center, I s p r a , Italy 989

H-3 The C h a r a c t e r i s t i c s of Thermionic C o n v e r t e r s Filled with Va­

por Mixture

V . D . BONDARENKO and Yu. K. GUSKOV, Institute of P h y s i c s

and Power Engineering, Obninsk, USSR 999

H-4 Unignited Mode Converter Diagnostics with Regard to E m i t t e r

Work Function Patches

E. WOLF, R. MAYER and M. SCHINDLER, Institut für K e r n ­

energetik d e r Universität Stuttgart, Germany 1011

H-5 Some P e c u l i a r i t i e s of I-V Curves of the Thermionic C o n v e r t e r s

in Cesium Vapor at the P r e s s u r e 10" - 5 T o r r

V . L . BORZENKO, S.V. DROBJAZKO, L . A . DROBJAZKO,

V.N. KNIZHNIKOV, I . V . Kurchatov Atomic Energy Institute,

Moscow, USSR 1019

H-6 E x p e r i m e n t a l Verification on the R a s o r Phenomenological T h e ­

ory of the Arc Mode Regime of a Cesium Thermionic Conver­

t e r

F . V . KOND RA TIE V and G. V. SINYUTIN, I . V . Kurchatov A t o ­

16

H­7

Ionization State of Cesium T h e r m i o n i c C o n v e r t e r P l a s m a

Page

F . K . KOSYREV, N. P . KOSYREVA and E . I. LUNEV, I . V .

Kurchatov Atomic E n e r g y Institute, Moscow, USSR

1041

H­8

On the Development of a Low­Voltage A r c in a T h e r m i o n i c

Diode with Extended E l e c t r o d e s

V . l . DERBILOV, D. V. KARETNIKOV, N. P . KOSYREVA,

A. F . NASTOJASHCHY, V. B. TURUNDA JE VSKY, I . V .

Kurchatov Atomic E n e r g y Institute, Moscow, USSR

1055

H­9

Kinetic T h e o r y of Knudsen A r c s in the Mixture of I n e r t

G a s e s with Cesium Vapour

R. J a . KUCHEROV, P h y s i c a l Technical Institute, State C o m ­

m i t t e e of Atomic E n e r g y , Sukhumi, USSR and A. E . NASTO­

JASHCHY, Kurchatov Atomic E n e r g y Institute, Moscow, USSR

1067

H­10 C u r r e n t Oscillations and E l e c t r o m a g n e t i c Radiation in Low­

P r e s s u r e T h e r m i o n i c C o n v e r t e r s

I. G. GVERDTSITELI, V. Ya. KARAKHANOV, R. Ya. KUCHE­

ROV, Z . A . OGANEZOV and V. K. TSKHAKAYA, P h y s i c a l

T e c h n i c a l Institute, Sukhumi, USSR

1079

H ­ l l Low­Voltage A r c in the C e s i u m ­ B a r i u m Mixture

I. G. GVERDTSITELI, R. Ya. KUCHEROV, G. I. TKESHE­

LASHVILI and V. K. TSKHAKAYA, P h y s i c a l T e c h n i c a l Institute,

State Committee of Atomic E n e r g y , Sukhumi, USSR

1091

H­12 Low­Voltage Knudsen A r c in the C e s i u m ­ I n e r t Gas Mixture

I. G. GVERDTSITELI, V. Ya. KARAKHANOV, R. Ya. KUCHE­

ROV, G. I. TKESHELASHVILI, V. P . TSIBEREV and V. K.

TSKHAKAYA, P h y s i c a l Technical Institute, State Committee

of Atomic E n e r g y , Sukhumi, USSR

1097

H­13 Investigations on Noble Gas C o n v e r t e r s

H. ALBRECHT, Β. SAGGAU and Η. STRECKER, Institut für

Gasentladungstechnik und Photoelektronik, U n i v e r s i t ä t Stutt­

g a r t , G e r m a n y

1105

H­15 Low­Voltage Cesium A r c in T h e r m i o n i c C o n v e r t e r with E x t e n ­

ded Cathode Surface

Μ. Β. BARABASH, E . P . BUSIGIN, V. G. GRIGORYJANTS and

I. P . YAVOR, Yoffe P h y s i c a l T e c h n i c a l Institute, Leningrad,

USSR

1113

H­16 E l e c t r o n S c a t t e r i n g in T h e r m i o n i c C o n v e r t e r s by Xenon, K r y p ­

ton and Argon

F . RUFEH and D. LIEB, T h e r m o E l e c t r o n C o r p o r a t i o n , Walt­

ham, M a s s a c h u s e t t s , USA

1123

H­17 P u l s e Investigation on T h e r m i o n i c C o n v e r t e r s

V. ORLINOV, T. DONCEV and B. GORANCEV, Institute of

E l e c t r o n i c s , Bulgarian Academy of S c i e n c e s , Sofia, B u l g a r i a

­ 17 ­

Page

Socialist Republic, B u c h a r e s t , Rumania

H­18 P r e ­ I g n i t i o n and Ignition C h a r a c t e r i s t i c s of C e s i u m T h e r m ­

ionic Diodes

K. SHIMADA, J e t P r o p u l s i o n L a b o r a t o r y , California Institute

of Technology, P a s a d e n a , California, USA

1139

SESSION J "PLASMA P R O P E R T I E S "

C h a i r m a n

: D r . D . V . KARETNIKOV

V i c e ­ C h a i r m a n : D r . N . S . RASOR

J ­ l

T h e o r e t i c a l and E x p e r i m e n t a l Investigation of Low­Voltage A r c

in T h e r m i o n i c C o n v e r t e r

F . G . BAKSHT, G . A . DJUZEV, V. B. KAPLAN, I. L. KORO­

BOVA, A . M . MART ZINO VS KYI, Β . Ya. MOIZHES, G . A . SHAH­

NASAROVA and V. G. YURIEV, Institute of S e m i c o n d u c t o r s of

the A c a d e m y of S c i e n c e s , L e n i n g r a d , USSR

1147

J ­ 2

The E l e c t r o n E n e r g y D i s t r i b u t i o n Function and the Rate of Non­

E q u i l i b r i u m Ionization in the N e a r ­ C a t h o d e L a y e r of the T h e r m ­

ionic C o n v e r t e r

F . G . BAKSHT, B. Ya. MOIS HES and Y. A. NEMCHINSKIY, In­

stitute of S e m i c o n d u c t o r s of the A c a d e m y of S c i e n c e s , L e n i n ­

g r a d , USSR

1161

J ­ 3

The P r o b e and S p e c t r a l Investigations of Dense P l a s m a T h e r m ­

ionic C o n v e r t e r s

G . A . DJUZHEV, A . M . MARTSINOVSKIY, B . Ya. MOIZHES,

G . E . PIKUS, V. B. KAPLAN, G . A . SHAHNASAROVA, V. G.

YURIEV, Institute of S e m i c o n d u c t o r s of the A c a d e m y of S c i e n ­

c e s , L e n i n g r a d , USSR

1173

J ­ 4

On the P l a s m a Sheath T h e o r y

F . G . BAKSHT, B. Ya. MOIZHES and V. A. NEMCHINSKIY, I n ­

stitute of S e m i c o n d u c t o r s of the A c a d e m y of S c i e n c e s , L e n i n ­

g r a d , USSR

1185

J ­ 6

An Investigation of the Ionization M e c h a n i s m s in the Ignited

Mode C e s i u m T h e r m i o n i c C o n v e r t e r

E . L. BURGESS, Sandia L a b o r a t o r y , A l b u q u e r q u e , New Mexico,

and D . O . AKHURST, U n i v e r s i t y of A r k a n s a s , F a y e t t e v i l l e ,

A r k a n s a s , USA

1199

J ­ 7

S p e c t r o s c o p i c Investigations in a T h e r m i o n i c C o n v e r t e r P l a s m a .

C. G. STOJANOFF, W. HOFFMANN and K. SEWING, Institut

für K e r n e n e r g e t i k d e r U n i v e r s i t ä t S t u t t g a r t , G e r m a n y

1205

J ­ 8

S p e c t r u m of the Low­Voltage D i s c h a r g e in a C e s i u m ­ F i l l e d

Diode

D. GLAS, Eindhoven Technological U n i v e r s i t y , Eindhoven, The

N e t h e r l a n d s

1213

- 18

P a

thermioniques, conversion du rayonnement solaire

J. P. DAVID et F . FLORET, Faculté des Sciences de M a r ­

seille, Marseille, France

SESSION K "SURFACE PHENOMENA"

Chairman : Dr. E. A. NIEKISCH

Vice-Chairman : Dr. E. P . GYFTOPOULOS

Invited P a p e r : Comments on Work Function Theories

by E„ P . GYFTOPOULOS 1225

K-l Quantum-Thermodynamic Meaning of Electronegativity and

Work Function

E. P . GYFTOPOULOS and G. N. HATSOPOULOS, Thermo

Electron Corporation, Waltham, Massachusetts, USA 1249

K-2 A New Interpretation of the Thermionic E m i s s i o n from Bare

and Covered Metal Surfaces

J. BOHDANSKY, Euratom Joint R e s e a r c h Center, Ispra, Italy 1267

K-3 The Cathode Materials of the T h e r m o - E m i s s i o n Converters

R e s e a r c h

Yu.S. BELOMYTZEV, F . L. BABINA, I. B. DMITRIEVA,

Yu. G. KOLOBKOV, V.A. MALYKH, Yu. I. MOSKALEVA,

I.N. PRILEZHAEVA, M. M. PRIVALOVA, V . M . PUMPURS,

E . M . SAVITZKII, L . N . SARATOVSKII, A . A . SMIRNOV, N. E.

SOLOMONOV, G. V. SPYVAK, M. A. TILKINA, B . B .

SHYAH-KIN, Institute of Physics and Power Engineering, Obninsk,

The Moscow State University, Moscow, USSR 1281

K-4 Work Function M e a s u r e m e n t s of Refractory Metals in a High

P r e s s u r e Cesium P l a s m a for Low Probe T e m p e r a t u r e Range

V. BUNDSCHUH, Institut für Technische Physik, Kernfor­

schungsanlage Jülich, Germany 1295

K-5 P r e p a r a t i o n and Investigation of Tungsten Surfaces with P r e f e r ­

red Orientations

P . BATZIES, J. DEMNY and H. E. SCHMID, Brown, Boveri

u. Cie, AG, Central R e s e a r c h Laboratory, Heidelberg, Ger­

many 1303

K-6 Recherche de surfaces de tungstène à travail de sortie élevé .

D. THIVELLIER, Centre d'Etudes Nucléaires de Saclay, F r a n c e 1313

K-7 Evaluation of Semiconducting Collector Surfaces in Thermionic

Converters

R. MALY, H. RAPP and W. KLUGE, Institut für Gasentla­

dungstechnik und Photoelektronik, Universität Stuttgart, G e r ­

many 1321

K-8 Wetting of Some Refractory Metals by Cesium, P o t a s s i u m and

Sodium

19

-Page

Center, Schenectady, New York, USA

K-9 Etude de l'adsorption du césium sur des monocristaux de

tungstène

T.· ALLEA U et J. L. DESPLAT, Centre d'Etudes Nucléaires

de Saclay, F r a n c e 1337

K-10 Adsorption de gaz sur des monocristaux de tungstène

F . P . DUMONT et J. MAURIES, Centre d'Etudes Nucléaires

de Saclay, F r a n c e 1347

K - l l The Influence of Oxygen on the Work Function of Tungsten

P . BATZIES, Brown, Boveri u. C i e . , A G . , Central R e ­

s e a r c h Laboratory, Heidelberg, Germany 1357

K-12 Work Functions of Polycrystalline W and Re in an A t m o s p h e r e

of Cesium and Oxygen

R. LANGPAPE and A. MINOR, Brown, Boveri u. Cie. , AG. ,

Central R e s e a r c h Laboratory, Heidelberg, Germany 1367

K-13 A Critical Experiment on the Nature of Adsorbed Cesium

F i l m s

E. MUZ, Institut für Gasentladungstechnik und Photoelektro­

nik, Universität Stuttgart, Germany 1381

K-14 Etude au m i c r o s c o p e à émission de surfaces r é f r a c t a i r e s en

p r é s e n c e de vapeur de césium

J. L. DESPLAT et P h . DEFRANOULD, L a b o r a t o i r e s de R e ­

c h e r c h e s Générales, Compagnie F r a n ç a i s e Thomson Houston,

92-Bagneux, F r a n c e 1389

SURVEY OF EXPERIMENTAL WORK IN THE USSR

by Yu. L. DANILOV, USSR 1399

PANEL DISCUSSION: " P r e s e n t and F u t u r e of Thermionic Energy Con­

v e r s i o n "

Chairman: Prof. P . D . DUNN

Invited P a p e r s : 1) The United S t a t e s ' Thermionic P r o g r a m

R e m a r k s by G, F . TAPE 1407

2) The Application of Thermionic Energy Conversion

in the USSR

R e m a r k s by Yu. L. DANILOV, 1417

Discussion (Moderator: Prof. P . D . DUNN) 1421

21

-OPENING SESSION

Welcome on Behalf of the Sponsoring Organization

by Mr. L. BOXER, Head of the Economical and Technical Division, E u r o ­

pean Nuclear Energy Agency, P a r i s .

Ladies and Gentlemen,

I am anxious to take up as little time as possible of this opening session,

but on behalf of the D i r e c t o r General of the European Nuclear Energy

Agency, I feel bound to r e c o r d our p l e a s u r e in a s s i s t i n g in the opening of

this Second International Conference on Thermionic E l e c t r i c a l P o w e r G e ­

neration. Our p l e a s u r e is twofold, in the sense that as an organisation, we

a r e proud to be associated with a function of such scientific importance,

and secondly that we a r e always glad to have a further opportunity to u n d e r ­

take with Euratom a cooperative e x e r c i s e , of which t h e r e a r e a l r e a d y plenty

of e x a m p l e s . We all owe p a r t i c u l a r thanks to Dr. NEU, the Chairman of the

P r o g r a m m e Committee of this Conference, and his colleagues at the I s p r a

Joint R e s e a r c h Centre, who have been responsible for all the m a t e r i a l

a r r a n g e m e n t s .

Those of you who have had a chance to glance through the little note on ENEA

in the back of your p r e l i m i n a r y p r o g r a m m e , will have seen that scientific

and technological cooperation between the twenty-one OECD countries on

peaceful applications of nuclear energy is one of our principal activities. We

firmly believe that t h e r e is a good deal of scope for m o r e co-operative a c ­

tivity in those applications of nuclear energy which a r e still far from the

stage of widespread c o m m e r c i a l exploitation, and which thus r e q u i r e con­

tinuing governmental support. The technique of thermionic power generation

from nuclear energy sources with its predominant application in space r e ­

s e a r c h , (an a r e a which is already the subject of m a s s i v e governmental in­

vestment), therefore falls very appropriately within our scope, especially

in view of its connection with heat s o u r c e s from radioisotopes, where we

have a p a r a l l e l interest, and indeed, an active cooperative Working Group

on radioisotopic battery development.

22

-up a Liaison Gro-up on Thermionic E l e c t r i c a l Power Generation, to p r o ­

vide a permanent mechanism for improving information exchange among

specialists designated from OECD countries, and for advising on the plan­

ning of these conferences. So far the Group has been successful in b r i n g ­

ing together experts from seven countries active in the field, also the

international i n t e r e s t s represented by Euratom and IAEA. It is planned

to enlarge future participation in the Group with experts from E a s t e r n

countries.

Once again, as in the case of the F i r s t Conference, it has been possible

to welcome fellow scientists and engineers from the USSR (and other E a s t e r n

countries) to our deliberations this week. Their p r e s e n c e h e r e , and the

scale of their contribution to this conference will be a significant element

in the important new revelations which might well e m e r g e during these five

days.

We have a full, fascinating and very varied p r o g r a m m e before u s , from d e ­

tailed theoretical considerations to design development, performance and

experience with thermionic g e n e r a t o r s over a wide range of e l e c t r i c a l out­

put. I feel sure that the experts in this increasingly important a r e a of science

and technology will leave S t r e s a at the end of this week with the feeling that

since the first conference in London three y e a r s ago, which ENEA had the

privilege of organizing with the collaboration of the Institution of E l e c t r i c a l

E n g i n e e r s , a v e r y considerable step forward has been achieved in the state

of the a r t . If that is the result, then we shall feel that the little trouble we

have taken to bring you h e r e has been m o r e than worthwhile.

Welcome on Behalf of the Organizing Institution

by Prof. H. KRAMERS, D i r e c t o r of the EURATOM R e s e a r c h Establishment,

I s p r a .

Ladies and Gentlemen,

23

-establishment of the E u r a t o m organization.

As a r e p r e s e n t a t i v e of this r e s e a r c h establishment I wish to thank you for

your confidence in this p r e p a r a t o r y work, which we could p e r f o r m , amongst

o t h e r s , because of the p r e s e n c e at I s p r a of a small, but highly proficient

r e s e a r c h group in the field of thermionic conversion.

We could have wished of c o u r s e that our effort in this field would have been

g r e a t e r , but I have to r e c a l l , that the p r i m a r y object of the countries which

constitute the European Atomic Energy Community is the promotion of r e ­

s e a r c h , development and industrialization of nuclear power on a large scale

and on an economic b a s i s . We r e a l i z e that the d i r e c t conversion of heat into

electricity by application of the thermionic principle does not fall into this

domain. On the other hand, we feel that among the various methods for d i ­

r e c t conversion, the thermionic principle combined with nuclear heat, will

sometime find its justified peaceful application, p a r t i c u l a r l y in s p a c e - b o r n e

s y s t e m s .

In the p r e s e n t competition between the various branches of "big s c i e n c e " such

a statement is hardly convincing if it comes to getting the n e c e s s a r y govern­

ment support in the form of funds. On the other hand, the development of

thermionic power generation devices is just a field where the long t e r m

c h a r a c t e r , the high risk, the slow r e t u r n on investment and the absence of

direct national economic and industrial considerations can still greatly profit

from free exchange of information and p a r t i c u l a r l y from international colla­

boration. If we a r e able to understand this and to g r a s p the occasion of i n ­

ternational collaboration, we - and I think now p a r t i c u l a r l y of Western Europe

would be able to meet the challenge, not only of our powerful world neigh­

bours, but also of the v e r y advanced technology p r o b l e m s which a r e a s s o ­

ciated with this field of thermionic conversion - not to speak of "fall-out"

or " s p i l l - o v e r " , which always occurs but does not constitute in itself an

argument for doing such work.

24

-particularly so, to o u r s e l v e s .

I therefore express my sincere hope that the conference will be a complete

s u c c e s s .

Introduction to the Conference

by Dr. H. NEU, Conference Chairman.

Ladies and Gentlemen,

I have the honour to welcome you in the name of the P r o g r a m m e Committee

and to thank you for coming to S t r e s a . F r o m the registration forms I l e a r n ­

ed that delegations of the following countries a r e p r e s e n t : A u s t r i a , Belgium,

Bulgaria, Canada, Czecho-Slovakia, F r a n c e , Germany, Italy,Rumania,

Soviet Union, Switzerland, The Netherlands, United Kingdom and the United

States of A m e r i c a . F u r t h e r m o r e , r e p r e s e n t a t i v e s of the following International

Organizations a r e r e g i s t e r e d : European Space R e s e a r c h Organization, E u r o ­

pean Launching and Development Organization, the International Atomic

Energy Agency and - who a r e the sponsors for this conference - the European

Nuclear Energy Agency and EURATOM.

We a r e particularly glad that a strong delegation of the USSR has a r r i v e d and

we a r e grateful for the support that the International Atomic Energy Agency

in Vienna has given us to make this possible.

R e s e a r c h on Cesium filled thermionic diodes was started about 10 y e a r s ago

in the laboratories of the USSR and independently in l a b o r a t o r i e s of the USA.

We a r e happy to see h e r e with us many of the pioneers of thermionic energy

conversion.

25

-testing. The session on "Integrated S y s t e m s " , that is to say conceptual engi­

neering studies of r e a c t o r s and isotope fueled power units (mostly for space

power supply), has become the l a r g e s t session. In this r e s p e c t the C o m m i t ­

tee would like to thank the USAEC for making possible important contribu­

tions on subjects which a r e published for the first t i m e .

Now let me tell you something about the scientific organization of this confe­

r e n c e . Those -who have attended the London conference may have a l r e a d y

noted that we a r e not using the so-called " r a p p o r t e u r s y s t e m " , that is the

presentation of all the p a p e r s of one session by one or two s p e a k e r s .

On the other hand, not all of the authors at this conference will be able to

read their paper. I feel that it is v e r y n e c e s s a r y to explain why this is and

how it came about.

The P r o g r a m m e Committee felt strongly that we should t r y to give the Con­

ference m o r e the c h a r a c t e r of a working meeting than of a r e p r e s e n t a t i v e

event. F o r this purpose, the " r a p p o r t e u r s y s t e m " has m o r e inherent d i s a d ­

vantages:

1. P a p e r s have to be submitted r a t h e r e a r l y to the o r g a n i z e r s for d i s t r i b u ­

tion to the r a p p o r t e u r s . Consequently the authors cannot always p r e s e n t

the latest r e s u l t s and they may have to use m a t e r i a l which has already

been published before.

2. It s e e m s to be difficult sometimes for the r a p p o r t e u r s to find out from a

written paper details of r e s u l t s which the author would r e g a r d as i m p o r ­

tant.

3. The younger colleagues do not have an opportunity for p e r s o n a l p r e s e n t a ­

tion.

26

-about a half of the session time is n e c e s s a r y for d i s c u s s i o n s .

What to do? P a r a l l e l sessions were not found to be a good solution because

we expected that most of the participants will be interested in all subjects

t r e a t e d . This is quite understandable, as thermionic r e s e a r c h is linked with

different disciplines such as physics, metallurgy and engineering in such a

way that each specialist in one field needs to know what happens in the other

fields. Thus, the P r o g r a m m e Committee was forced to accept a solution

in which only a selection of the p a p e r s a r e presented by the a u t h o r s . The

titles of the papers which a r e not presented orally will be read by the c h a i r ­

man and put to discussion.

The selection of papers for oral presentation was indeed a delicate task for

the P r o g r a m m e Committee because it had to be done with only the p r e l i m i ­

nary a b s t r a c t s available. We have tried to do our best to select those papers

for oral presentation which we felt to contain the most of novelty or to be of

a m o r e general i n t e r e s t . This selection means absolutely no judgment of the

scientific value of the content.

As a general rule, we suggest to the Session Chairman to give priority to

questions and a n s w e r s r a t h e r than general r e m a r k s , read and unread p a p e r s

being treated equally. If time is available authors of unread papers may have

a chance to make some r e m a r k s . It is quite possible that the Committee was

not able to fully a s s e s s some of the papers from the a b s t r a c t s alone, or

additional time has become available because p a p e r s have been withdrawn.

There will be a possibility to reexamine papers in this case together with

the Chairman and the Vice-Chairman before each session.

In o r d e r to save time, we have recommended that some of the authors c o m ­

bine their p a p e r s if the contents a r e s i m i l a r and we have also asked that

two or m o r e papers coming from the same laboratory should be presented

by one speaker. In the session "Heat Pipe S y s t e m s " we have invited two

speakers to s u m m a r i z e work in the USA and E u r o p e . There is no oral p r e ­

sentation of p a p e r s foreseen at all on the subject of heat pipes since this

does not - in our opinion - belong strictly to the r e s e a r c h sphere.

Con 27 Con

-v e r t e r s" and "Surface Phenomena".

As you will note, we have taken a full half day for a panel discussion about

subjects which a r e not only of i n t e r e s t for the thermionic r e s e a r c h e r s but

for those who attend this conference to get a m o r e complete picture of the

possible application of thermionic c o n v e r t e r s , the competition with other

s y s t e m s and the opinion of the specialists on p r e s e n t and future of t h e r m i o ­

nic s. I have great p l e a s u r e in announcing that c o m m i s s i o n e r Gerald Tape of

the USAEC will personally come to S t r e s a and give an introductory talk about

"Space Applications of Thermionic Conversion and Comparison with other

S y s t e m s " . He also intends to participate on the discussion about this subject.

You will a g r e e with m e , that this gives the panel discussion a special i m p o r ­

tance and weight.

With regard to the general organization, t h e r e is some information in the

P r o g r a m m e l i t e r a t u r e you have received. If any p r o b l e m s a r i s e , please

do not hesitate to contact one of the p e r s o n s with an orange coloured badge.

I am m o s t indebted to all who have contributed to bringing the conference to

the point where it can now s t a r t . In p a r t i c u l a r , I would like to thank Dr.

SMETS and M r . BOXER of the European Nuclear Energy Agency in P a r i s

and the m e m b e r s of the P r o g r a m m e Committee for the p r e p a r a t i o n of this

conference. Many thanks also go to Prof. KRAMERS, d i r e c t o r of I s p r a for

his great i n t e r e s t and support, the authors of p a p e r s for t h e i r collaboration

in submitting their p r e p r i n t s in t i m e , the m e m b e r s of the conference s e c r e ­

t a r i a t for their v e r y efficient "work and, last but not least, the staff of the

Public Relations Office at I s p r a for making all a r r a n g e m e n t s for the s u œ s s

-ful running of thi s conference.

A-1

SUMMARY OF APPLIED RESEARCH PROGRAM

IN THERMIONIC CONVERSION DURING RECENT YEARS

F . Rufeh, D. Lieb and L. van Someren

T h e r m o Electron Corporation

85 F i r s t Avenue, Waltham, M a s s a c h u s e t t s

I. ABSTRACT

This paper s u m m a r i z e s the r e s u l t s of an applied r e s e a r c h p r o g r a m

which has been in p r o g r e s s for s e v e r a l y e a r s . Two new techniques have

been developed for treating e m i t t e r surfaces. T h e s e techniques, which

have resulted in substantial improvement in p e r f o r m a n c e , a r e combina­

tions of heat t r e a t m e n t with electropolishing and with electroetching.

E m i t t e r s p r e p a r e d by t h e s e methods w e r e incorporated in v a r i a b l e

-spacing c o n v e r t e r s , and p a r a m e t r i c data was obtained. T h e s e data a r e

useful both for calculations of converter designs and for t h e o r e t i c a l analy­

sis. Another technique investigated for improving converter p e r f o r m a n c e

was the use of oxygen. Cesium oxide was found to be a good s o u r c e of

oxygen and cesium.

II. TEST CONVERTER

A v e r s a t i l e v a r i a b l e - s p a c i n g converter •was developed to obtain

p a r a m e t r i c data for the various emitter surfaces. A schematic diagram

of this converter is shown in F i g u r e 1. The molybdenum collector is

surrounded by an active molybdenum guard ring which is maintained at

the s a m e t e m p e r a t u r e and e l e c t r i c a l potential as the collector. Flexible

bellows allow the i n t e r e l e c t r o d e spacing to be v a r i e d from 0. 5 to 100 m i l s .

- 30

III.- C O N V E R T E R S W I T H E L E C T R O P O L I S H E D RHENIUM E M I T T E R S 1

A. E m i t t e r P r e p a r a t i o n

T h e e m i t t e r s u s e d in t h i s w o r k w e r e d i s c s of p o l y c r y s t a l l i n e r h e n i ­

u m m a d e by r o l l i n g s i n t e r e d - p o w d e r i n g o t s . T h e m a t e r i a l w a s at l e a s t

99- 99% r h e n i u m; and had a w e l l d e v e l o p e d p r e f e r r e d o r i e n t a t i o n with

b a s a l (001) p l a n e s p a r a l l e l to the e m i t t e r s u r f a c e .

T h e d i s c s u r f a c e s w e r e g r o u n d flat, and h o h l r a u m s w i t h the —

6 D r a t i o of 5 w e r e m a d e by s p a r k - m a c h i n i n g . An a n n e a l for 30 m i n u t e s

- 6

at 1 7 0 0aC at a p r e s s u r e of l e s s t h a n 10 t o r r followed g r i n d i n g b e c a u s e

this w a s found to f a c i l i t a t e e l e c t r o p o l i s h i n g .

T h e s p e c i m e n w a s t h e n e l e c t r o p o l i s h e d , h e a t - t r e a t e d and i n c o r ­

p o r a t e d into a v a r i a b l e - s p a c i n g c o n v e r t e r with a m o l y b d e n u m c o l l e c t o r .

B. P a r a m e t r i c D a t a

T h e e l e c t r o d e w o r k f u n c t i o n s w e r e m e a s u r e d , a n d the p e r f o r m ­

a n c e of the c o n v e r t e r w a s r e c o r d e d in t e r m s of v a r i a b l e c e s i u m

-t e m p e r a -t u r e f a m i l i e s . A -t y p i c a l f a m i l y is shown in F i g u r e 2. I-t

defines an e n v e l o p e w h . c h is t a n g e n t to e a c h 1-V c u r v e and r e p r e s e n t s

the c e s i u m o p t i m i z e d p e r f o r m a n c e . Such f a m i l i e s w e r e o b t a i n e d at

o p t i m u m c o l l e c t o r t e m p e r a t u r e for a w i d e r a n g e of e m i t t e r t e m p e r a t u r e s

and i n t e r e l e c t r o d e s p a c i n g s . T h e e n v e l o p e s of t h e s e f a m i l i e s a r e s u m ­

m a r i z e d in F i g u r e s 3 to 5. E a c h of t h e s e f i g u r e s s h o w s the fully opti­

m i z e d p e r f o r m a n c e with r e s p e c t to c e s i u m t e m p e r a t u r e , i n t e r e l e c t r o d e

s p a c i n g and c o l l e c t o r t e m p e r a t u r e . T h e output is c o r r e c t e d for e m i t t e r

lea d v o l t a g e l o s s w h i c h is 3 m V / a m p . T h e fully o p t i m i z e d p e r f o r m a n c e

for i n t e r e l e c t r o d e s p a c i n g > 5 m i l s and t h e e m i t t e r t e m p e r a t u r e r a n g e

of 1680 t o 2 0 4 0 " K is s u m m a r i z e d in F i g u r e 6. T h e s e t of d a t a shown

31

-IV. CONVERTERS WITH ELECTROETCHED RHENIUM EMITTERS

A. E m i t t e r P r e p a r a t i o n

The emitter p r e p a r a t i o n for these e m i t t e r s is s i m i l a r to the e l e c t r o

-polished emitter with the following difference: After being electro-polished,

the e m i t t e r s were subjected to electroetching. This p r o c e s s r e m o v e s

m a t e r i a l selectively from different c r y s t a l faces, so that some grains

a r e etched faster than o t h e r s . A rough jagged surface is developed,

which has a l a r g e r fraction of the slow-etching b a s a l planes than did

the original surface. Since these b a s a l planes a r e favorable for

cesiated thermionic emission, the etching technique is expected to

produce an emitter with a thermionic performance superior to that of

the electropolished surface from which it was derived.

These surfaces also w e r e h e a t - t r e a t e d for 3 hours at 2380°C to

ensure stability during converter operation.

B. P e r f o r m a n c e Data

F a m i l i e s of v o l t - a m p e r e c h a r a c t e r i s t i c s w e r e generated by varying

the cesium r e s e r v o i r t e m p e r a t u r e . The performance of the device has been

32

-and e l e c t r o p o l i s h e d e m i t t e r s a r e c o m p a r e d in F i g u r e 1 1 . T h e i n t e r e l e c ­

t r o d e s p a c i n g s in t h i s s e t a r e e q u a l to or l a r g e r than 5 m i l s and t h e output

is c o r r e c t e d for e m i t t e r l e a d v o l t a g e l o s s . E t c h e d r h e n i u m shows a s u b ­

s t a n t i a l i m p r o v e m e n t o v e r p o l i s h e d r h e n i u m .

C. E m i t t e r W o r k F u n c t i o n

E m i t t e r w o r k function w a s d e t e r m i n e d f r o m the m e a s u r e d s a t u r a t i o n

c u r r e n t u n d e r i o n - r i c h c o n d i t i o n s . The d a t a is p r e s e n t e d in F i g u r e 12 a s

a function of kTt In P , w h e r e k is the B o l t z m a n n c o n s t a n t , Tg is e m i t t e r

t e m p e r a t u r e , and Ρ is c e s i u m p r e s s u r e . T h i s d a t a w a s a l s o p l o t t e d a s a

function of TE/ TR ) w h e r e TR is c e s i u m r e s e r v o i r t e m p e r a t u r e . It s h o w e d

a m a x i m u m s c a t t e r of about 0. 1 volt, i n d i c a t i n g that w o r k function does

not depend only on TE/ TR, but s t i l l has a s m a l l d e p e n d e n c e on TE.

A new c o r r e l a t i o n w a s t r i e d by plotting 0E v e r s u s kTE In ( P / C ) , w h e r e

7

C = 3. 6 χ 10 . T h e c o n s t a n t C is c h o s e n in an a t t e m p t to obtain a u n i v e r ­

s a l r e l a t i o n b e t w e e n 0E and TE and P . The s c a t t e r in the data for t h i s c o r ­

r e l a t i o n is r e d u c e d to 0. 05 V.

D. V a r i a b l e - S p a c i n g Data

F a m i l i e s of v o l t - a m p e r e c h a r a c t e r i s t i c s w e r e g e n e r a t e d by v a r y i n g

the i n t e r e l e c t r o d e s p a c i n g while all the o t h e r p a r a m e t e r s w e r e held con­

s t a n t . T h e c e s i u m p r e s s u r e , e m i t t e r t e m p e r a t u r e s and i n t e r e l e c t r o d e

s p a c i n g s in t h e s e f a m i l i e s w e r e s e l e c t e d in s u c h a w a y a s to yield the

volt-a m p e r e c h volt-a r volt-a c t e r i s t i c s volt-at v volt-a r i o u s c o m b i n volt-a t i o n s of P d volt-and ion r i c h n e s s

v a l u e s . T h e data is useful for p l a s m a a n a l y s i s and is shown in F i g u r e s 13

to 19.

V. E L E C T R O N E G A T I V E ADDITIVES

A. Effect of C e s i u m F l u o r i d e

3, 4, 5

In p r e v i o u s i n v e s t i g a t i o n s f l u o r i n e a p p e a r e d to p r o d u c e a s u b s t a n ­

t i a l c h a n g e in the e m i s s i o n c h a r a c t e r i s t i c s of m e t a l s u r f a c e s . E x p e r i m e n ­

33

-in p e r f o r m a n c e , but the effect was not reproducible and disappeared after

a short t i m e . A m a s s - s p e c t r o m e t r i c examination of the outgassing of

cesium fluoride showed that, in the previous m e a s u r e m e n t s , the vapor

p r e s s u r e of water was high enough to affect the emission c h a r a c t e r i s t i c s

and overshadow the effect of fluorine. An elaborate t e s t vehicle was

used to study the effect of specially purified C s F p e l l e t s . These and

other r e s u l t s showed that even where t h e r e is significant fluoride

coverage, the emitter work function is not i n c r e a s e d as much as in the

p r e s e n c e of oxygen. The i n c r e a s e in work function produced by fluoride

is 0. 3 eV, while that produced by oxygen is 0.7 eV. The conclusion is

that, in the previous studies, water vapor contamination had been

responsible for the initial improvement and the later deterioration of

p e r f o r m a n c e .

7

B. Converter Performance with Cesium plus Cesium Oxides

Cesium oxides w e r e formed on the collector and guard surfaces of a

variable-spacing converter. The additive p r e s s u r e was controlled by

the t e m p e r a t u r e of the collector and guard, and cesium p r e s s u r e was

controlled by the cesium r e s e r v o i r t e m p e r a t u r e . A definite oxygen

effect was observed when the collector and guard t e m p e r a t u r e s w e r e

r a i s e d in the range of 600 to 900°K. Oxygen produced a d e c r e a s e of

0. 3 volt in the cesiated work function of the e m i t t e r .

The performance improvement was equivalent to an i n c r e a s e in

spacing by a factor of four at the s a m e output. A 300-hour life t e s t

showed stable performance within ± 10%. .

Q

C. Converter P e r f o r m a n c e with Cesium Oxide Only

34

-t e m p e r a -t u r e range of cesium was from 560 -to 640°K. In

cesium-oxide-only data, the t e m p e r a t u r e range of cesium oxide was 670 to 700

K.

Therefore, the coldest component of the cesium-oxide-only converter is

about 100'K hotter than the coldest component of the cesium converter.

There is a possibility that the operating t e m p e r a t u r e of the cesium-oxide

r e s e r v o i r can be further increased. A higher t e m p e r a t u r e range would

make cesium-oxide-only converters m o r e attractive for most applications.

Figure 20 shows a comparison of the envelopes of the cesium-only and

the cesium-oxide-only families. The cesium-oxide envelope has a steeper

slope than the cesium envelope because the cesium p r e s s u r e s a r e lower

and electron scattering is l e s s .

A 400-hour life test showed stable performance within i l 0%.

ACKNOWLEDGMENT