Millimeter wave technology

for Advanced Energy

Conversion

Dec.22th 2014

Yasuhisa ODA

Japan Atomic Energy Agency

Today’s topic

• Introduction of millimeter wave

• High power millimeter wave generator – High power 170GHz gyrotron development in JAEA

• Activity for ITER EC system

– TL, Launcher, Control system

• Application of high power MMW

• Microwave Rocket

Introduction of Millimeter wave

Electromagnetic Waves

• Millimeter wave (MMW)

– Character of radio wave and light

– High power generation by vacuum tube

– Quasi-Optical Beam

Radio waves Light X Ray MF/HF/VHF/UHF

(Com. / Broad Cast) Microwave

FIR

THz wave

Visible Light IR UV

Millimeter wave

3GHz 30GHz 300GHz 30MHz 300MHz 3THz ・・・・

10m 1m 10cm 1cm 1mm 0.1mm

High power millimeter wave generators

• Gyrotron – Oscillator tube

– Kinetic energy of electron beam is converted to electromagnetic wave through cyclotron resonance MEASER (CRM) effect

– The useful oscillator for high power millimeter wave

• Gyro-Klystron – Amplifier tube

– CRM effect

• Free Electron Laser (FEL) – Particle acceleration device

– Wide frequency range oscillator • Microwave ~ X-ray

– Periodic changing of B-field

– Ultra high power : >10MW

High power millimeter wave generator

High power 170GHz gyrotron

development at JAEA

History of gyrotron development

• 1958

– Discover of oscillation principle

(Cyclotron Resonance MEASER /

CRM) by Twiss

• 1964

– First gyrotron development in IAP

USSR

• 1976

– First experiment of electron

cyclotron resonance heating at

TM-3 / USSR

Introduction: Key components of

high power Gyrotrons

2/14

Main

Magnet

Gun

Magnet

SCM

e -

Cavity

25 kV DC break

converter

RF beam

MIG

Output diamond window

Electron beam

RF power profile

TE31,8 mode

Resonator Cavity

Diamond

Window

0

2p 20

225

21.5

0

r (m

m)

Internal mode converter

Inner surface of

dimpled wall mode converter

Electron gun (Cathode)

Anode

Body

Pitch factor a(=Vprep. / Vpararell.)

Magnetic field

e- beam

Electron Gun (Magnetron Injection Gun)

Activity for ITER EC system

JAEA tries to support the

integration of ITER EC system

TL, Launcher, and Control System

ITER EC H&CD system

Schematics of ITER’s

ECH/ECCD gyrotron,

transmission line, and

launchers.

JAEA 170GHz

1MW Gyrotron

EQ-Launcher with quasi

optical design

ITER EC H&CD major components

3 upper port launcher (8MW each)

1 equatorial port launcher (24MW)

24MW gyrotrons (8 tubes for each country)

RF transmission lines (125m - 24sets)

12 sets of main HVPS (HVPS for 2GYs)

JAEA EC system test facility

Gyrotron test stand

TL test stand

EL mock

up

Long range TL

Upper straight section (6 m)

Lower straight section (18m)

WG valve I

WG-SW-I

WG-SW-II

To EL mock up

Short range TL

Gyrotron

CCR dummy I

CCR dummy II

Vertical WG sections

WG valve II

MOU

JAEA ITER relevant TL test stand

General Atomics WG switch

WG size: 63.5 mm

Furukawa WG switch

WG size: 63.5 mm

40m length of 63.5 mm corrugated waveguides system with

5 miter bends, a polarizer, 2 waveguide switches, 2 dummy loads

TL transmission efficiency (170 GHz)

Upper straight section (6 m)

Lower straight section (18m)

WG valve I

WG-SW-I

WG-SW-II

To EL mock up

Gyrotron

Dummy load 1

Dummy load 2

WG valve II

PDL(longTL) = 390 kW

PDL(shortTL) = 411 kW

PMOUout = 416 kW

hDL(shortTL) = PDL(shortTL)/ Pwin

= 95.6 %

hDL (longTL) = PDL(longTL)/ Pwin

= 90.7 %

LP01 94.4 %

LP02 1.3 %

LP11odd 0.5 %

LP11even 0.1 %

LP01 94.4 %

LP02 0.3 %

LP11odd 1.5 %

LP11even 0.2 %

LP01 93.1 %

LP02 1.1 %

LP11odd 0.6 %

LP11even 1.3 %

RF beam profile at Long TL end RF beam profile at Middle of TL

RF beam profile at MOU output

0 4 8 12 16 20 24

Oscillation Time [s]

Ic = 26 A

Vak = 37.5 kV

Vbk = -72.5 kV

Pwin = 430 kW

Body voltage

Beam current

Anode voltage

Cathode voltage

RF signal

RF

RF

shield

Waveguide Focus mirror

Closure plate

Waveguide

Miter bend

Actuator for

steering

Steering mirror

Full scale - 1/3 unit

RF

Mirrors, waveguide lines, cooling lines and etc… were fabricated. • Manufacturability check : Structure, Interface, Cooling line management

• High power test : Estimate stray RF, Diffraction effect, etc…

• RH compatibility study of the mirrors and the waveguide components

EL prototype (based on design)

Closure plate Steering mirror

High power experiment

Duct

edge

RF

RF

Waveguide – M1 M1 – M2

Front side

Power-pulse : 160kW-10sec, HE11 : 86%

It was observed that

• temperature of the wall around the mirrors and waveguide outlet was increased.

• the side wall temperature increased.

• stray RF went behind the mirrors.

IR

IR

RF

Beam

duct

Beam

duct

Qualitative measurement will be done.

Controller architecture for JAEA EC

system test facility

GY-TS (short pulse) TL-TS EL mock up MHVPS

Host Slow Controller

S7-300 PLC

Slow Controller

S7-300 PLC

Slow Controller

S7-300 PLC

Fast Controller

NI PXI system

Mini CODAC

HMI & etc.

EC Plant Controller

(Main Controller)

SDN

ProfiNet

PON

TCN

Fast Controller Slow Controller

Millimeter wave transmission

technology for high power

system

EC transmission line system for

ITER project

Maxwell equation for traveling

wave

HE j

0 E 0 H

EH j

xyz HjE

y

E

yz

x Hjx

EE

zxy

Hjy

E

x

E

xyz EjH

y

H

yz

x Ejx

HH

zxy

Ejy

H

x

H

0

z

yx Ey

E

x

E

0

z

yx Hy

H

x

H

( z

zyx eEEE zyxE ( z

zyx eHHH zyxH

Wave equation in

waveguide

x

H

y

Ej

kH zz

c

x 2

1

y

H

x

Ej

kH zz

c

y 2

1

y

Hj

x

E

kE zz

c

x 2

1

x

Hj

y

E

kE zz

c

y 2

1

02

2

2

2

2

zc

zz Hky

H

x

H02

2

2

2

2

zc

zz Eky

E

x

E

TE mode TM mode

TM mode and TE mode

Et Et Et

Ez

E Ht Ht Ht

Hz

H

TE mode TM mode TEM mode

Hybrid wave HE mode / EH mode

Wave equation in

waveguide

01

2

2

1

2

Hk

x

Hx

xkAxkAH xx sincos 211

02

2

2

2

2

Hk

y

Hy

ykBykBH yy sincos 212

Rectangular waveguide

( z

z eyxHH ,0( ( ( yHxHyxH 210 ,

( ( 2

2

1

2

2

2

1

2

1

11ck

x

H

yHx

H

xH

( 0

0

0

xx

xyH ( 0

0

0

yy

xyH

( 00

axx

xyH ( 00

byy

xyH

0,0 22 BA

b

nk

a

mk yx

pp ,

ykxkCHHH yx coscos210

Boundary conditions

a

b

x

y

z

Wave equation in

waveguide

01 2

2

2

zc

zz Hkr

H

rr

H

( ( z

cmcmz emrkBNrkAJH cos

Circular waveguide

0

ar

z

r

H ( rZ

cmcz emrkJAk

r

H

cos

( 0 akJ cm

ak

nm

c

,

0,0

BHrz

( z

cmz emrkAJH cos

Boundary conditions a

r

z

Mode profile in circular WG

TE01 TE11

TM01 TM11

lc=2.613a lc=1.640a

lc=1.640a lc=3.412a

Waveguide for High power

MMW

Rectangular waveguide

D-band Corrugated waveguide

D: 63.5mm,

Hybrid mode in corrugated WG

TE01

TM01

HE11

( z

rmzi emrkBJH cos1

( z

rmzi emrkAJE sin1

HE11 mode is…

Profile is consisted from TEM mode contents

→ Radiated beam propagates as TEM beam

E and H field gets nearly 0 at waveguide wall

→ Very small surface loss

Combinations of TE,TM,HE EH modes

＝

＝

＋

＋

TE mode

TM mode

HE21 mode

HE21 mode Linear polarized profiles

Linearly Polarized mode (LP modes)

LP01 pattern LP11 pattern

（HE21+TE01/TM02）

LP21 pattern

LP12 pattern LP02 pattern

More than 2 modes (TE/TM/HE/EM modes) have same propagation constants.

Those modes are coupled as combination mode which has linear polarization.

Application of high power millimeter

wave

A disk of FeO was radiated by short pulse RF from 170GHz gyrotron.

Fast Heating (Example: FeO）

W.G.

FeO disk

Mirror

RF Temp. Monitor

170GHz/0.2MW(~16kW/cm2) 2msec input : 400degree of increment

Collaboration with NIFS and JAEA（Iron making by microwave）

Beamed Energy Propulsion

• High payload ratio – Propulsive energy is

provided from the ground.

– Atmospheric air is utilized as propellant.

• Energy supply from ground – The beam station is used

for many launches.

Low Cost Launch System Illustration of BEP launch image.

Microwave Rocket

How can high power microwave

launch new “moon” into orbit?

Microwave Rocket Test in JAEA

φ100

L300

109g

（Al）

RF beam

Launcher

Thruster

RF beam Thrust

force

High pressure

Shock wave

Open end tube

Atmospheric plasma

using 170GHz high power beam

– The ionization front propagates towards in supersonic velocity.

RF

55sec

Photograph of plasma on the beam channel

Photographs by High

framing speed camera

18,000FPS

RF Condition

RF Power

P = 730kW

(S = 50kW/cm2)

RF Pulse duration

t = 0.5msec

570m/sec

450mm

Ignition

reflector

RF Power P=930kW, Pulse duration t=0.2msec,

RF

2D parabola

reflector

Microwave Shock Wave

driven by atmospheric breakdown

• Visualization of shock wave generated by millimeter wave plasma.

High speed movie by HPV-1 (Shimadzu co.ltd.)

Visualization of shock wave generated in 2D-reflector and ignition rod.

(Visualized by shadow graph method.)

mm-Wave

Ignition pin

Reflector

Microwave Supported Shock Wave Model

• Energy conversion model by combination of normal shock wave and isobaric heating.

• Analogy of slow combustion with shock wave.

( 11

21 2

1

1

2

Mp

p

( ( (

2

1

2

12

1

1

2

1

121

1

21

M

MM

T

T

Normal shock wave

Plasma

Energy absorption

Rarefaction wave

u1

p1, T1

u2

p2, T2

u3

p3, T3,

u4=0

p4, T4

Normal shock wave relation

Pressure

Temperature

32 pp

11

2

22

23

h

h

uc

ST

uc

STT

pp

1

2

3

1

3

1

4

2

11

CM

p

p

p

p

3

13

3a

uuM C

Plasma region (Heat addition)

Rarefaction wave relation

Energy input hq

Shadow graph view of 1D Microwave

shock wave propagation in a tube

#1 (t = 325 s) #2 (t = 350 s) #3 (t = 375 s)

#1 (t = 467 s) #4 (t = 553 s) #7 (t = 600 s)

Case 1: I=95 kW/cm2, Camera frame rate 80kFPS, (Ushock = 480 m/s, Uioniz = 453 m/s)

Case 2: I=41 kW/cm2, Camera frame rate 15kFPS, (Ushock = 401 m/s, Uioniz = 175 m/s)

Shock wave

Shock wave

Ionization

front

Ionization

front

Summary

• High power millimeter wave generator – Achievement of three frequency gyrotron

• Activity for ITER EC System – RF power transmission in corrugated waveguide

– Full scale launcher mockup

– Control system

• Application of high power MMW – Material production, High resolution radar

– Material heating, Space propulsion

• Microwave Rocket – Thrust generation and atmospheric plasma research