Stimulated Electromagnetic Emissions - Ionosphere Modification Facilities

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Physics and Measurements of

Stimulated Electromagnetic Emissions

Paul A. Bernhardt, Stan Briczinski

Plasma Physics Division

Naval Research Laboratory

Washington, DC 20375

University of Maryland

8 November 2011



Studying the Ionosphere with Active Experiments

• Active Experiments with High Power Radio Waves

– Frequency Range (2.6 to 10 MHz) – Global Distribution of HF Facilities

• Physics of High Power Radio Waves

– Density, Temperature, Composition, and Irregularities

– Active Technique• Field Aligned Irregularity Glow with HF Excitation

• Stimulated Electromagnetic Emissions (SEE)

– Plasma Wave Generation and Propagation

• Research Inspired by Uppsala University

– Low Frequency

– OAM HF Beam Interactions

• Dissertation Defense



The Ionosphere Described by NRL SAMI3 in 2010

• Ref.: Huba, Krall, Joyce,

SAMI3, 2010• Plasma Density:

103 to 106 cm-3

• F-Layer Electron Temp.:500 to 3000 K

(0.05 to 0.3 eV)• F-Layer O+ Ion Temp.:

500 to 2000 K

• Magnetic Field Strength:B0 ≈ 28 10-6 T

• Plasma Pressure VersusMagnetic Pressure

β ≈ nkT/(B2 /2µ0) = 10-8

• Ion Collisions Versus IonGyro Orbits

Ωi ~ νi at 100 km Altitude



Past, Current and Future HF

Ionospheric Modification Facilities

Jicamarca

Arecibo

Conjugate



F-Region Ionosphere

Stimulated Electromagnetic Emissions,Radar Backscatter, Enhanced Plasma Waves and Artificial Aurora

HF Radar HAARP TransmitterHF Receiver HF Receiver UHF Radar Camera



Plasma Physics of Ionospheric Modification withHigh Power Radio Waves

High PowerElectromagnetic

Wave Beam

ElectronTemperature

Elevation

PlasmaIrregularityFormation

ElectrostaticWave

Generation

PlasmaPressure and

DensityChanges

EnhancedRadar

Scatter

ParametricDecay and

StrongTurbulence

VLF Ductsand

ConductivityModification

LowFrequency

Waves

VLFWaveguides

and VLFGeneration

ModeConversion

HighFrequency

Waves

ElectronAcceleration

ArtificialAurora

StimulatedElectro-

magnetic

Emissions

Plasma

Line

Ion Line



HF Antenna for ReceivingStimulated Electromagnetic Emissions from HAARP



Real Time Display of Stimulated ElectromagneticEmissions near HAARP with the MARK-IID Receiver



ES and EM Wave Generation

Optional ModeConversion

EMPumpWave

High

Power EM or ES

Wave

ParametricDecay

Optional ModeConversion

HighFrequencyEM or ES

Wave

Received

EM Wave

LowFrequencyES Wave

Loss

Loss

Loss

Possible Mode

Conversion ?

LowFrequency

EM Wave

DM

2DM

3DM

UM

BUM

Pump

In SituSource:Upper

HybridWaves

In SituSource:ElectronBernstein

Modes

4.10 4.15 4.20 4.25 4.30

-10

-20

-30

-40

-50

-60

Frequency (MHz)

R e l a

t i v e P o w e r ( d B )



HAARP HF Transmitter Array2.6 to 10 MHz, Up to 3.6 GW Effective Radiated Power



Heater Power Beam Angle Sweeping

IAIA & EIC

Norin et al., 2009 observed the IA emission lines f1 and f2 due to Simulated Brillouin Scatter; Bernhardt et al.,2009 observed IA lines f1 and 2010 observed IA line f1 and EIC lines f3 ;Bernhardt, P. A., C. A. Selcher, and S. Kowtha (2011), Electron and ion Bernstein waves excited in theionosphere by high power EM waves at the second harmonic of the electron cyclotron frequency,

Geophys. Res. Lett., 38, L19107, doi:10.1029/2011GL049390. The experiment conducted at HAARP in July, 2010 aims to look more thoroughly at a broaderrange of heater beam angle effects on IA and EIC waves generated by MSBS (Fu, Scales,Bernhardt 2011).

I: Vertical beam (0o,0o)II: Zenith beam (14o ,202o)

Vertical

11



Generalized MSBS matching conditions

0

2 2 1/ 2

0

2 2

0

For O mode reflected at

1For X mode reflected at [ ( 4 ) ]

2

The upper hybrid resonance is

p

ce ce pe

UH ce pe

ω ω

ω ω

ω ω ω

=

= ±Ω + Ω +

= = Ω +

-f4 -f3 -f2 -f1

Reflection

Upper hybrid

[Bernhardt , 2009 ]

f1- IA at reflection region;f2- IA at upper hybrid;f3- EIC at reflection region;

f4- EIC at upper hybrid; 12

S S



- 1 8 0 H z

- 1 2 0 H z

1 2 0 H z

1 8 0 H z

Stimulated Brillouin Scatter withIon Acoustic Wave Generation is Simple

EM1

IA1

EM2

SBS-1

B

P u m p

S B S - 1

f I A 1

θ = 0



B

Brillouin Scattering of the 4.5 MHzHAARP Vertical Beam

in the Ionosphere



SBS with EIC Generation Yields Ion Mass

O f f s e t F r e q u

e n c y ( H z )

Radio Beam Angel with B (θ)

B θ

f E I C - 1

f I A - 1

111.1 Azimuth 16.3 Zenithmi = e B/fEIC = m[O+]

fEIC-1

fIA-1

- 1 8 0 H z

- 1 2 0 H z

1 2 0 H z

1 8 0 H z

Set II : Experimental Results for 4 1 MHz O mode



Set II : Experimental Results for 4.1 MHz, O-modeFull Power, UT 04:15:00-04:60:00,07/22/2010

(Haiyang Fu, Virginia Tech)

•The IA lines f1=10~12 Hz is stronger close to the magnetic zenith•The IA lines f2=24~26 Hz appears for ZA=28o, AZ=202o

•The EIC lines f3=50~52 appears for ZA=28o

, AZ=202o

•The newly observed f4=70~72 appears for ZA=28o, AZ=202o

f1=10~12 Hz;f2=24~26 Hz;

f3=50~52 Hz;f4=70~72 Hz; 16



Stimulated Ion Bernstein (SIB) Generation by Tuning

to the Second Electron Gyro Frequency

EM0 EB0

FAI

IB1

EB1

EM1

FAI

SIB1

IB2

EB2

EM2

FAI

SIB2

IB3

EB3

EM3

FAI

SIB3



Stimulated Ion Bernstein Waves with f0 = 2 fce

• HF Tuned to 2nd

Electron Cyclotron Harmonic• Ion Cyclotron Frequency = 55 Hz

• Dropout of Ion Cyclotron Mode

• Constant Amplitudes for Ion Bernstein Modes

• Observed at All Pointing Angles

• Search for Narrowband Ground ELF Signal



Direct ULF Generation

• Process – HAARP 3.6 MW HF transmitter

– High Gain Phased Array Antenna

12 x 15 Dipoles Each Excited by 20 kW

Phased to Tilt HF Beam Greater than 20 Degrees from B

– Frequency Tuned Away from Gyro Harmonic (4.2 MHz)

Decay of Pump WaveElectrostatic Ion Cyclotron Wave

Downshifted EM Wave

Coupling of EIC wave to ULF EM Mode on Field AlignedIrregularities

– Detection with Ground Receivers

UFL Receiver Tuned to About 48 Hz

HF Receiver Tuned to 4.2 MHz with 250 kHz BW

• Results – EIC Mode Second Strongest Produced

– Strong Dependence of HF Beam Orientation



F-Region Ionosphere

Stimulated ULF and HF Electromagnetic Emissions with HAARP

HAARP TransmitterULF ReceiverHF Receiver



HAARP Array Generates a Hollow Beam

AntennaGain (dB)



22

Artificial Ionospheric LayersCreated by the HAARP Transmitter

HF Twisted Beam

Layer 1Layer 2

Frequency (MHz)

A l t i t u d e ( k m )

• Objectives

– Form Stable Plasma Layer

– Open Artificial Propagation Path

• Progress

– Demonstrated Twisted Beam

– Formed Layer Lasting 5 Minutes

– 4th Harmonic Resonance

– Cyclotron Resonance Theory

SEE Near the 4th Gyro Harmonic and Artificial Layers



23

SEE Near the 4th Gyro Harmonic and Artificial Layers

25 March 2011 00:53:00 UT

25 March 2011 00:51:30 UT

Layer Produced for 4.5 Minutes



0 3 : 3 2 : 0 0

-1 0 1 2 3 4 Seconds

3.2 MHz

+50 kHz

-50 kHz

-100 kHz

26 August 2011 SEE 03:32 UT



27August

2011SEE00:04

UT

0 1 2 3 4 5 6 Seconds

6.1 MHz

+100 kHz

+200 kHz

+300 kHz

-300 kHz

-200 kHz

-100 kHz

0 0 : 0 4 : 0 0

HF SEE R i U C l i



HF SEE Receiver Use Conclusions

• Simple New Experiments for HAARP

• 4th

Gyro Harmonic Heating with Twisted Beam – Broad Upshifted Maximum and Ion Bernstein Waves in SEE Obtained

with the Mark II-D Receivers

– Long Lasting Artificial Plasma Layers at Fixed Altitude

• Coordinated Receiver Observations

– HF SEE Modes Measured with the Mark II-D Receivers – ULF Ground Modes

• Acknowledgments

– NRL Support by Geoff San Antonio and Serafin Rodriquez

– MIT Lincoln Support by Scott Coutts and Matthew Morris

• Future Work – Plasma Science Instruments in Space – HF Receiver

– Langmuir Probe

– Magnetometer

Stimulated Electromagnetic Emissions - Ionosphere Modification Facilities

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