High power millimeter wave sources for fusion program; ECH source development program strategy; and 1 MW, 140 GHz gyrotron experiment design philosophy are briefly outlined. This presentation is represented by viewgraphs only

George, T. V.

English

NASA Technical Reports Server

N90-21805
HIGH POWER MILLIMETER WAVE SOURCE DEVELOPMENT
T.V. George
U.S. Department of Energy
Washington, DC 20545
HIGH POWERMILLIMETER WAVE SOURCES
FOR FUSION PROGRAM
MOTIVATION:
A) FUSION APPLICATIONS
1. BULK HEATING
2. CONTROL OF MHD MODES
3. RADIAL TEMPERATURE PROFILE CONTROL
4. PRE-IONIZATION AND START-UP
5. CURRENT DRIVE
6. DIAGNOSTICS
B) ISOTOPE SEPARATION
C) POWER TRANSMISSION
D) MILITARY APPLICATIONS
PROGRAM
HIGH POWER MILLIMETER WAVE SOURCES
FOR FUSION PROGRAM
HISTORYOF INDUSTRIALDEVELOPMENTOF GYROTRONS:
INITIATED28 GHZ, 200 KW, CW GYROTRONDEVELOPMENTIN 1976
SUCCESSFULLYCOMPLETEDIN 1980
INITIATED60 GHZ, 200 KW, CW GYROTRONDEVELOPMENTIN 1980
SUCCESSFULLYCOMPLETEDIN 1984
• INITIATED140 GHZ, 100 KW, CW GYROTRONDEVELOPMENTIN 1984
SUCCESSFULLYCOMPLETEDIN 1986
• INITIATED140 GHZ, 1 HW, PULSEDICWGYROTRONDEVELOPMENTIN 1986
PROGRESSINGSATISFACTORILY
153
https://ntrs.nasa.gov/search.jsp?R=19900012489 2020-03-19T23:21:35+00:00Z
154
HIGH POWER MILLIMETER WAVE SOURCES
FOR FUSION PROGRAM
MAIN TECHNICAL OBJECTIVE: PLASMA HEATING
REOUIREMENTS:
CURRENT:
NEAR-TERM:
MID 90'S:
200 KW - 2 MW @ 60 GHZ, CW
6 MW @ 115 GHZ, CW
10-30 MW @ 280 GHZ, CW
ECH SOURCE DEVELOPMENT PROGRAM STRATEGY
DEVELOP 140 GHZ, 1 MW, PULSED GYROTRON IN A COST-
EFFECTIVE WAY USING
- VARIAN'S PAST EXPERIENCE
- ONGOING WHISPERING GALLERY EXPERIMENTS AT MIT
IN PARALLEL
- ESTABLISH DATA BASE FOR 280 GHZ, WHISPERING
GALLERY MODE AT MIT
- ENGINEERING FEASIBILITY TESTS AND CONCEPTUAL
DESIGNS AT VARIAN
- EVALUATE NEW CONCEPTS WHICH COULD BETTER MEET
THE FUSION NEEDS
SHALL PERIODIC FEM
CARM
OUASI-OPTICAL GYROTRON
SDIO SUPPORTED PULSED FEL
TRW'S CW FEL
SCIENCE RESEARCH LAB'S PULSED FEL
RUSSIAN 2.1 MW COAXIAL CAVITY GYROTRON
155
OFFICE OF FUSION ENERGYCURRENTDEVELOPHENT ACTIVITIES
BUDGET
TASK
140 GHZ GYR.
140/280 GHZ
O-O GYR.
SHALL PER. FEL
TRANSH. SYSTEN
LI.NIJFEL-DRIVER
HISC, .... =,
]N_TITUTION P.I. 1987 1988 1989
VARIAN aORY/FELCH 1000 1500 2000
NIT TENKIN 400 450 ?
NRL HANHEIHER 205 250 ?
U, Hi) GRANATSTEIN 250 250 ?
U. WISC. VERNON 100 100 ?
LI.NL CAPLAN 0 1100 ?
TOTAL (APPROXINATELY) 2000 3900 4100
1 MW, 140 GHz GYROTRON EXPERIMENT
DESIGN PHILOSOPHY
• DEMONSTRATE 1 MW AT 140 GHz FOR SHORT PULSES WITHIN A SHORT
TIME PERIOD WITH PROVIDED FUNDS
(NOT A TRUE DEVELOPMENT EFFORT WITH MULTIPLE EXPERIMENTS AND
PARALLEL DESIGN APPROACHES)
• DEMONSTRATE SEVERAL HUNDRED kW CW TO BEGIN BUILDING
TECHNOLOGY BASE FOR 1 MW CW
• BUILD UPON
-- CURRENT 140 GHz DEVELOPMENT WORK
-- 1 MW STUDY OF 1983
-- 1 MW EFFORT AT MIT
-- VARIAN IR & D OVER PAST 1-1/2 YEARS
156
OSCILLA TOR TECHNOLOG Y CONCERNS
• WINDOWS
• MODE COMPETITION IN LARGER CAVITIES
• CAVITY WALL COOLING
• OUTPUT COUPLING
• BEAM TUNNEL LOADING
ECff SOURCE DEVELOPMENTPROGRAMPLAN
(BASED ON CURRENT FUNDING)
- CONTINUE WITH THE 140 GHZ, 1 MW, GYROTRON DEVELOPMENT
AT VARIAN
- INITIATE 280 GHZ WHISPERING GALLERY STUDIES AT MIT
- ESTABLISH A CW, MEGAWATT TEST FACILITY BY 1990
- CONDUCT SINGLE PULSE FEL HEATING EXPERIMENT ON MTX
REEVALUATE DATA BASE AND INITIATE 280 GHZ, MEGAWATT
INDUSTRIAL SOURCE DEVELOPMENT IN FY 1990
157

QUASI-OPTICAL GYROTRON DEVELOPMENT
Wallace Mannheimer
Naval Research Laboratories
Washington, DC 20375
Quasi-Optical Gyrotron (NIIL)
Advantages=
Huch less of a problem with vall loading
Beam eolleetlon and radiation extraction aL differenL places;
Especially important if depressed eolleeLlon Is used
Diffieultles
Complicated magnet design
DOE Requirement=
Tube For ECIIII o£ CIT and subsequent reactors
P> 1HW
f = 300 Gllz (Or maybe as high as 600 Gllz)
n :_ 20:%
Cg (Or at least 3 second) relevant
159
PRECEDING PAGE BLANK NOT FILMED
OUASI-OPTICAL RESONATOR CONFIGURATION
rF
_0 -- w°
d
-\ /
5pher ical _-- D iFFr_cI" ion
M i rror ou_-put- coup I ', ng
MAGNET DEWAR
output \ I
WINDOW/J
MICROMETER /
\
B
f
\,
i '
I'
F
I
/
- "1
/ COLLECTOR
/
f _
ELECTRON GUN
MODIFIED
HELMHOLTZ
COIL
_W OUTPUT
INDOW
RESONATOR
160
NRL ©dASI-ORTICAL GYROTRON
Iq
E
ORIGINAL PAGE IS
OF POOR QUALITY
161 ORIGINAl.; PAGE
BLACK AND WHITE PHOTOGRAPH
ORIGINAL PAGE !S
OF POOR QUALITY
162 ORIGINAL" PAGE"
BLACK AND WHITE PHOTOGRAPH
Diagnostic Setup
Directionol
coupler
Detector J
I Oscilloscope ]
Funda+t]entol
Lood box _ w oveguide
_i plckup
cornputerSperryIT d-- --]lleteridFlerec°rderTransientl'q'11"
Waveguide
lee
Ir
__.i__[+++o++,+i
Heterodyjle Diagnostic
Ilarmonlc
Variable mixer
Ilttenultor
co.,-,o'_%1
t
Directional Dlrectlontd
coupler coupler
Variable
elltenuator
Frequency locked
¥[G tuned
oscillator
12-1B Gill
0 0
O--[,oo .,,. n.ndp.....t.r}--O
O--{ ,o m,...,,dp... ,,,,. ]-O
O--[ ,o .,,. _..d.... ',".. }-_D
fIF= +/" (fRF" n fLo)
n = Harmonic number
Bandpass filters centered at 160 MHz
40 dB
I Detector ;
163
Mognetic Field Profile
30,
o 20.
Trt_r'lv+_r[,,, ,i ,, ,, i,,,, i_,, ,i,,,, I .... I,,,TI,,,,I .... i, ,, ,t, ,, ,l_rl_nT
S0
40.
10. /
O. -- ........ :=:"--:J" 3 "-''''''''-'e_"
-10. ____I+u.LLLLL_Jj,, ,I+L_.LJ._.+J.+ I • _, l,, *, I ,, =, I, +,, I, *,, h,,, I,,, ,I =,,, I+LL_
....... _ o = += + _ _ == =o, P=
i i _ i
1: r=
2: r-
z (_)
0.000
0 714
c
v
o¢:
TEM 0,0
SO , -- , , ,
Rc = 160 cm
d=8cm
3, = 0.26 cm
20
_5
,o Mirror edge
.05
.00
r/rmo=
Lois O R Tqanlmilted _ ol lolll
Dilfr¢cllon S.6621+04 3.41_1-01 8.22
Slo[(1) S,0i91403 3,814¢+00 91.78
letol 4,6S31403 4,1S_l+OO
164
frame
xlO -z
0.20
0,15
LU0.10
OCO--O.IIZE+OI BOC= O.
J
0,05- /
0,00
-0.60
x]O-Z
o:lfUJ O.
°'
o. l f
-0.60
0.3C
0.2C -
Ld
O.IC -
0.0C
- _.GO
]0:08:05
203/Z4/88
T= EFF=.000
I -a__ r
-0.13 0.33
(W-WO)/WO
T= 1, EFF=.O00
-- LLJ
I
0,80
xlO -l
-O.t3 0.33
(W-WO)/WO
T= O. EFF=.058
1
-0.13 0.33
(W-WO)/WO
I
0,80
xlO-t
OW=0.600E-OZ IB= 0.999E+01
0.3[
0.2C
0,1[--
0.0[
-0.60
0.25
T= IO. EFF=.075
1
-0.13 0.33
(W-WO)/WO
T= 50. EFF=,170
x10-t
I l
0.80
0,20--
0,1_--
0, ]()---
o,oS-
0,001
-0.60
0.2_
0 .ZC--
0.]_--
0.]C-
O .0_--
0.0C
-0
-0.13
(W-WO)/WO
T= GO. EFF=.]28
0.33 0.80
xlO-I
/I
.60 -0.13 0.33 0.80
(W-WO)/WO x10-i
SC KR = 0.000
165
Mode Spectrum for QOG at 75 kV, 14 Amp and 47 kG
G)
"10
.._=
Q.
E
<
G)
>
.m
G)
n-
100
8O
60
4O
2O
0 I ! * I I L !
115 117 119 121 123 125
Frequency (Ghz)
10
2
¢L
E
G)
.>
n-
Mode Spectrum for 75 kV, 14 Amp and 47 kG
100
8O
GO
4O
20
0
-0.02 0.00 0.02 0.04 0.06 0.08 O. 10
Detuning
g Flat
• Spiky
166
Operalion at 75 kV and 20 cm Separation
v
O
D.
120
100
8O
6O
4O
20
0
0
J
t
m i ! J • o • ! m
5 10 15
Power 44 kG
Power 47 kG
Power 50 kG
Cotleclor Current (Amp)
Operation at 75 kV and 20 cm Separation
>,,
t'-
(}
_E
tU
14
12
10
o
0
i i , ! , I A
5 10 15
Elf. 44 kG
•-_ Elf. 47 kG
-¢P Elf. 50 kG
Collector Current (Amp)
]57
]20 , , • ,- ,
N
I
L9
v
(.]
f-
D
O-
L
Li_
]15
110
105 i
45
|
50
A 1 i I e I i
55 60 65
El_ctron Energy (k_V)
I
70 75
23O
25 cm Mirror Smporotion
225
220
215 i i i i i i , ,
168
FUTURE PLANS
• INSTALL 80 KEV, 35A VUW8144 (MIT) ELECTRON GUN
• MODE CONTROL BY MODE LOCKING AND BY STRUCTURED
MIRRORS
• HARMONIC OPERATION
• ACHIEVE P = I MW WITH USE OF A 6 MW SHEET BEAM
ELECTRON GUN
PHASE LOCKED 85 GHz GYROTRON
\, / \_
PREBUNCH OUTPUT
CAVITY CAVITY
ISSUES
• STABILIZE PREBUNCHING CAVITY
• ISOLATE CAVITIES
• MAXIMIZE LOCKING BANDWIDTH
I00 KW
169
CARM Dispersion Relation
\
-\
\
\ \
r ...... T
- _}() I _
0
/
Wave Numher (era-')
i i
15 30
DOWNSTREAM REFLECTOR UPSTREAM REFLECTOR
"g a2
L2
AXIAL POSITION
170
Bragg Cavity Modes
o
g
o
6
c_
o
Oo
o
g3
rEs,!
o
o
g
o.
o
070
i 7
98.0 99.N
R= 0.7790 lO = 3.55
II = 5.00 at= 0.0150 kl = 37.200
12= 3.00a2 = 0.0135 k3= 37.200
TE 6,1
lOO.O l _11.0 r102.9 I NI3.0
frequency
TE 7,1
IN4.0 IN 5D 106f) 107 0
t-
Z
Ul
0
n
w
0
0
Z
--l
0.
'7
0
0
0.5
0.0,
0.2
80
TM MODES
TE,,
//
7
/
TEo, _ TE,z
TEo= TE.=
1OO
FREQUENCY (GHz)
120
171
F-
ro
F-
,.4
LL
uJ
¢}
I"Q
0
0
0
90.0 95.0
UPSTREAM REFLECTOR
NSTREAM R EFLECTO__
! ! !
100.0 105.0 110.0
FREQUENCY (GHz)
PRELIMINARY DESIGN PARAMETERS OF 250 GHz LONG PULSE CARM EXPERIMENT
Electron Beam
Gun type
Beam cross sectlon
Beam dlameter
Beam voltage
Beam current
Pulse width
Veloclty pitch ratlo
Pitch angle spread llmlt
Energy spread llmlt
temperature-llmlted MIG
annular
1.1 cm
SO0 kV
100 amp max
1 psec
0.71
2 percent
7 percent
Resonator
Cavfty type
Reflector type
Output reflectlvlty
Operatlng mode
Nave group veloclty
Cavlty length
Cavlty dlameter
Ohmlc heating
circular wave guide
Bragg reflector
92 percent
TEl4 (volume mode)
0.97c
~ 10 cm
1.8 cm
3 kN/cm 2
Magnet type
Cavlty magnetic fteld
superconductlng
~ 55 kG
Predlcted efficiency
Predicted output power
20 to 40 percent
I0 MH
172
BEAM APERATURE
ANOD ,i
": -_ 600KV 6Ka 55nse¢ FEBETRON
COPPER SULFATE
• ,'izTii_,J,-_i_
CANM DIODE ....................... t
INSULATOR
OU'  TW,  OWII[ 
ELECTRON GUN TRIM COIL
MAIN SOLENOID
173
ORIGINAL PAGE IS
OF POOR QUALITY
ORIGINAL PAGE
BLACK AND WHITE PHOtOGRAPI't
35-GHz FEL AMPLIFIER
THEORETICAL GROWTH
CURVES
3
i2
Z
0
20
I =600A
), = 2.75
Br = 1.04 kG on axis
B z -- 11.0 kG ;_v = 3 cm
I L t I (
3O 4O 50 60 70
FREQUENCY (GHz)
]74
RANSITION
DIODE
x/-1 •
lr
I OIL _,
VAC -
CATHODE
// S wIGGLER
,/
/
COIL ANECHOICCHAMBER
/
_- MICROWAVE
HORN
WINDOW
,, MICROWAVE
DETECTORS
/
ZANODE
AGNET COIL
NITRON
N.R.L. F.E.L. EXPERIMENT
107
106
105
104i
35 GHz FEL AMPLIFIER
Pout vs Pin
L=54cm
t//
/
t"
i
l I d i I;11[
10
,/r
///"
//_//
/
/
//][/
/
/
/ Pout = 2700 Pin
/
/
I i I I IIIl_ I I I I tllll I I I J l I Jl
102 103 104
Pin (W)
175
m
-o
z
<_(.9
n-
uJ
o
n
6O
35 GHz FEL AMPLIFIER
GAIN vs LENGTH
5O
40
30
20
10
Pin = 40 W
1.2 dB/cm-_z j-
//_ti i
//_ 11
_/ii//
///t
/t /
40 50 60 70
TOTAL SYSTEM LENGTH (cm)
E
rn
"O
Z
(3
35 GHz FEL AMPLIFIER
GROWTH RATE vs AXIAL FIELD
o
lO
B r = 1.16 kG
y = 2,75
L1 = 54.15 cm
, ,
11 12 13 14
T
'1
15
AXIAL MAGNETIC FIELD (kG)
176
VEBA MILLIMETER-WAVE FEL
AMPLIFIER CONFIGURATION
MAGNETRON
TO
POLYETHYLENE SCREEN
INPUT WIGGLER WINDOW ='_"1 ('_ ROOM
ooo,,, R co,, / iiii
_ / / ;111K, BAND
• _ -- / J"_/ :IIIwAvEGU,DE
JBB • • II • NDARD
.I / ANECHOIC - _J- n_lR,
/ MICROWAVE CHAMBER J _ ....AXIAL FIELD COILS HORN _ ORN
MICROWAVE-PRODUCED ATMOSPHERIC PRESSURE
AIR BREAKDOWN
FOCUSED
MICROWAVES
FROM
FREE-ELECTRON
LASER
f = 75 GHzp = 75 MW
STANDING
WAVE
PATTERN
t
METAL
I TARGET
I
!
FOCAL
PATTERN
\
\
\
177

RECTIFYING DEVICES FOR ENERGY CONVERSION: TUNGSTEN SILICIDE
SCHOTTKY BARRIER DIODES AT 10 6 MICRONS*
Howard E. Jackson and Joseph T. Boyd
University of Cincinnati
Cincinnati, Ohio 45204
AN OUTLINE
HOTIVATION
BRIEFLY REVIEW THE PHYSICAL PROCESS
COMMENTS ON DESIGN
CHARACTERIZATION - INCLUDING
- A BRIEF ASIDE ON WSI2 CHARACTERIZATION
- DEVICE RESPONSE IN THE FAR-INFRARED
CURRENT STATUS
RECOMMENDATIONS FOR FUTURE EFFORTS
OBJECTIVE
HAXIMUM IRRADIATION FROM THE EARTH IS
IN THE 8 - 14 MICRON RANGE,
THIS CORRESPONDS TO A PHOTON ENERGY
RANGE FROM .155 EV TO ,0866 EV.
USE:
POWERING SATELLITES.
ADVANTAGE:
No TRACKING MECHANISM REQUIRED.
ABLE TO GENERATE POWER AT ALL TIMES AND
POSITIONS OF ORBIT.
Work supported by NASA Lewis Research Center grant
NAG3-583.
PRECEDING PAGE BLANK NOT FILMED
179
ENERGY BANDGAPS OF SEMICONDUCTORS
SILICON (SI)
GERMANIUM (GE)
GALLIUM ARSENIDE (GAAS)
GALLIUM PHOSPHIDE (GAP)
INDIUM ARSENIDE (INAs)
INDIUM PHOSPHIDE (INP)
INDIUM ANTIMONIDE (INSB)
CADMIUM SULPHIDE (CDS)
LEAD SULPHIDE (PBS)
LEAD SELENIDE (PBSE)
1.12 EV
0.7 EV
1.4 EV
2.3 EV
0.4 EV
1.3 EV
0.2 EV
2.6 EV
0.4 EV
0.3 EV
MERCURY CADMIUM
TELLURIDE (HGI=xCDxTE)
x=0 -0.142 EV
x=l 1.49 EV
PLASMON-ASSISTED INELASTIC ELECTRON TUNNELING
PHOTON _ (JUNCTION) PLASMON
_ ___ ENERGETIC E- _-_
--_ TUNNELING ACROSS A BARRIER
180
EXTRACTING POWER FROM
SURFACE PLASMA OSCILLATIONS
PHRSE MATCHING
SUNLIGHT TO PLASMONS
BROADBAND
ENERGY
TRANSPORT
TUNNEL
GUNCTION
RRRRY
SEMICONDUCTOR
METRL
d. A_,,/,-.-,.'- ("_s4
COMMENTS ON DESIGN
MAXIMIZE COUPLING OF EM WAVES TO SP0
(I) THIN METAL FILM
(II) HIGH PLASMA OSCILLATION
FREOUENCY
(III) LOW RESISTIVITY METAL
(IV) LOW REFLECTIVITY METAL
MAXIMIZE TUNNELING CURRENT
(I) HIGH DOPING CONCENTRATION
(II) LOW EFFECTIVE BARRIER
(III) LOW TEMPERATURE OPERATION
MAXIMIZE RESPONSE TIME
(I) LOW RESISTANCE & CAPACITANCE
(iI) HIGH ELECTRON MOBILITY
CURRENT
181
(I) TUNGSTEN SILICIDE THICKNESS
OF 200 TO 300 ANGSTROMS.
(II) CONTACT METAL (AL) THICKNESS
OF 1 uM.
(III) THE DIFFUSED N-TYPE LAYER
FORMING THE ACTIVE DEVICE
WAS i uM DEEP.
(IV) THE P-TYPE GUARD RING FOR THE
GUARD RING SCHOTTKY DIODE
WAS 1,5 uM DEEP.
(V) THE DOPING CONCENTRATION OF
THE N-TYPE LAYER WAS CLOSED
TO THE SOLID SOLUBILITY
LIMIT FOR PHOSPHOROUS IN
SILICON I X 1020 CM-3.
(VI) THE SUBSTRATE WAS HIGH
RESISTIVITY P-TYPE <100>
SILICON.
_ql Contact
to si I icide
guard r
p-type si I icon <100>
(a) CROSS SECTION
Thin metal/
silicide
Rl Contact
to n-1 ayer
/
/
II
.k
:°
I
(b) TOP VIEW
OPTICAL DETECTOR STRUCTURE
182
DEVICECHARACTERIZATION
- I - V MEASUREMENTS - OPTICAL RESPONSE
- C - V MEASUREMENTS - VISIBLE
- SHEET RESISTANCE MEASUREMENTS
- INCLUDING RTA OF WSI2
- FAR-INFRARED
,¢
e-
v
h-
Z
uJ
n-
rr
O
O
u_
u3
c_
O
0
I-V CHARACTE RISTICS
FORWARD BIAS (298K)
REVERSE BIAS (298K)
•1 -2 .3 .4 .5
BIAS VOLTAGE (VOLTS)
o
c,,
Z
LU
rr
nr
0
0
I-V CHARACTE RISTICS
FORWARD BIAS (78K)
REVERSE BIAS (78K)
0 •1 .2 .3 .4 .5
BIAS VOLTAGE (VOLTS)
183
UTILITYOF THE SILICIDEAS
A GATE AND INTERCONNECT MATERIAL
FOR VLSI
• GOOD ADHESION PROPERTIES
° HIGH TEMPERATURE STABILITY
• LOW RESISTIVITY
SUITABLE FOR GROWING AN
INSULATING LAYER BY OXIDATION
SAMPLE PREPARATION
DEPOSITION OF TUNGSTEN
Magnetron Sputtered at a base pressure
of 10-7 Torr.
C."
Film Thickness 20 nm.
Si
Uniformity 1 nm.
FORMATIONOF TUNGSTEN SILICIDE
Rapid Thermal Anneoling in
10% H2 ond 90% AF Atmosphere
WSi2
Time 90s/20s "_.
Thickness 50 nm.
Stoichiometry WSil.4 (RBS) Si
Tempereture 800C -
ANNEAL INGTEMP RATURE
i-.
1 l !
300 350 400 4SO 500 550
WAVELENGTH, NM
RESPONSIVITY OF TUNGSTEN DIODE
184
1300 C
BOO
]200 C
I]00 C
310 320 330 340
WAVENUMBERS (CM-I)
Raman spectra oF rapid thermal
annea[eol tungsten sltlclde
Properties of tungsten silicide
films rapid thermally annealed
at different temperatures
Materiol
W
WSI2
W_2
W_2
WSI2
RTA tmnp
C
--- 68.34
950 30.9
1000 24.5
Intensity
,f 332m_1
Rarnon
line
31.7
86.6
Peak
Podtml of
3321m-1
line
331.0
33?_O
FtMtM
(cm--1)
mm_
RaUo of
,kr_W
Peak
1100
1200
1300
20.7
24.2
314.6
93.3
105.7
128.6
334.1
333.7
334.0
8.7 1.0
7.6 1.19
6.4
6.1
1.31
1.21
1.255.9
185
HeNe LASER
T
CO2
LASER
ARGONLASER
BEAM
SPLITTER-,
/
CO2 ATTENUATOR-t
\
CHOPPER
o
\
\
PIIOTODETECTOR;"
ZnSe
WINDOW--.,
-\
\
DEWAR AT
LN2 TEMPERATURE
SETUP FOR DIODE TESTING
186
RESPONSE TO HeNe LFISER (6328
Measurement Temper_tur_ 78 " K
F_)
18 4
E
u
\
_18 -s
E
Z
k_
a2
tD
I
O
F-
O 10 -e
i
CL /
i i ' ''_I I I I..I ct,tJ , , , , ,,J,t J , , , ,_,,I _ , , J ,J_UJ
1 {_-6 I {a-s I 0 -4 I {}-3 i _+..z
INCIDENT PONER DENSITY (Natts/cm^; _)
RESPONSE TO F]RGON LFISER (5
Mea_:urmment Temper aturm 78 ° K
18 -z
i45
_J
(
E
U
\
o 0__ol
E
C£
Z
L_
rY
rY
-q 10-4
U
I
0
b-
(D
I
m
i i I I i s J I I i i i i i i i i , '
I(;a -_ i0 "I
INCIDENT PONER DENSITY (Natts/cm^2)
I L i I I 1
187
tO °
H(-
IJ
L
$-
3
u
Voltage (V)
dI
dV
i •
Volt_9_ (V)
d21
dV2
Voltag_ (V)
THEORETICAL RESPONSIVITY CURVES
Second Harmonic Response
OQ
OD
i
0
x
v 0
¢q
"o
i
.114
_05 -10
BIAS VOLTAGE (VOLTS/
,15
0
0
o o .,
X
_>
2o
_o
£
0
0 1 2
INCIDENT POWER (pW)
4
188
SUMMARY FUTURE EFFORTS
* DESIGNED AND FABRICATED A
TUNGSTEN SILICIDE SCHOTTKY
BARRIER DIODE
* OPTICAL RESPONSE OF PRESENT
SMALL STRUCTURES
* A RTA SILICIDE PROCESS WAS
INVESTIGATED
* ELECTRICAL CHARACTERIZATION WAS
CARRIED OUT
** DEMONSTRATED RESPONSE TO OPTICAL
RADIATION AT A WAVELENGTH OF
10.6 MICRONS
* FUTURE DIRECTIONS IDENTIFIED.
* FABRICATION AND CHARACTERIZATION
OF SUB-MICRON STRUCTURES
* DEVELOP ELECTRODE/ANTENNA
STRUCTURES
* OPTICAL RESPONSE AND OUANTUM
EFFICIENCY OF ARRAYS OF
SUB-MICRON STRUCTURES.
189

CONCLUSIONS
J.L. Christian, Jr.
NASA Lewis Research Center
Cleveland, Ohio 44135
The free-space power transmission concept has been demonstrated. Several
prototype systems and components have been developed and successfully tested
at 2.45 GHz. Extensive studies have determined the applicability of this con-
cept to missions such as the SPS, the Canadian SHARP, and the CO-OPS Program.
The applicability or practicality of this concept could only be determined
by its competitiveness over more conventiona] techniques of power generation
in space (solar and nuclear). In most NASA and DOD scenarios, the separation
distance between the transmitter and receiver ranges from a few tens to several
thousand kilometers. Because of mass constraints, antenna sizes shou]d be
kept to a minimum, forcing the system to operate at higher frequencies and,
consequently, to attain a high-power interception efficiency. To remain com-
petitive, this kind of system should operate at frequencies above 100 GHz.
No system above 2.45 GHz has been developed. A prototype system operat-
Ing at 35 GHz seems to be the next logica] step, since technology is a]ready
avallable at that frequency. Technology at I00 GHz and above seem to be feasi-
ble, but not available in the immedlate future. Development of antenna, RF-
power-generation, and rectenna technology Is necessary for working systems at
these frequencies.
A substantlal effort in these areas is being sponsored by the Government,
the mllitary, academ|a, and industry. Although this effort is not directed
toward the development of a free-space power transmission system, the outcome
of these programs is app]Icable to beam power technology. A combined effort
of all the parties involved should contribute to an early and cost-effective
deve]opment of such technology.
PRECEDING PAGE BLANK NOT FILMED
191
Report Documentation PageNational Aeronautics and
Space Administration
1. Report No 2. Government Accession No. 3. Recipient's Catalog No.
NASA CP-10016
4. Title and Subtitle
Free-Space Power Transmission
7. Author(s)
9. Performing Organization Name and Address
National Aeronautics and Space Administration
Lewis Research Center
Cleveland, Ohio 44135-3191
12. Sponsoring Agency Name and Address
National Aeronautics and Space Administration
Washington, D.C. 20546-0001
5. Report Date
November 1989
6. Performing Organization Code
8. Performing Organization Report No.
E-4161
10. Work Unit No.
11. Contract or Grant No.
13. Type of Report and Period Covered
Conference Publication
14. Sponsoring Agency Code
15. Supplementary Notes
16. Abstract
NASA Lewis Research Center organized a workshop on technology availability for free-space power transmission
(beam power). This document contains a collection of viewgraph presentations that describes the effort by
academia, industry and our national laboratories in the area of high-frequency, high-power technology applicable
to free-space power transmission systems. The areas covered were rectenna technology, high-frequency, high-
power generation (gyrotrons, solar pumped lasers, and free electron lasers), and antenna technology. This work-
shop took place on March 29-30, 1988, at NASA Lewis Research Center.
17. Key Words (Suggested by Author(s))
Rectenna; Gyrotron; Free electron laser; Inflatable
antenna; Solar pumped laser
18. Distribution Statement
Unclassified - Unlimited
Subject Category 20
19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No of pages
Unclassified Unclassified 192
NASAFORM1626oct 66 *For sale by the National Technical Information Service, Springfield, Virginia 22161
_U,S GOVERNMENT PRINTING OFFICE:] 9 9 o -7 t_8 - 1 5 _/ 0 0 2 ] I.
22. Price*
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