Physics and Measurements of Stimulated Electromagnetic Emissions Paul A. Bernhardt, Stan Briczinski Plasma Physics Division Naval Research Laboratory Washington, DC 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: 10 3 to 10 6 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: B 0 ≈ T Plasma Pressure Versus Magnetic Pressure  ≈ nkT/(B 2 /2  0 ) = Ion Collisions Versus Ion Gyro Orbits  i ~ i 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 Transmitter HF Receiver UHF Radar Camera

Plasma Physics of Ionospheric Modification with High Power Radio Waves High Power Electromagnetic Wave Beam Electron Temperature Elevation Plasma Irregularity Formation Electrostatic Wave Generation Plasma Pressure and Density Changes Enhanced Radar Scatter Parametric Decay and Strong Turbulence VLF Ducts and Conductivity Modification Low Frequency Waves VLF Waveguides and VLF Generation Mode Conversion High Frequency Waves Electron Acceleration Artificial Aurora Stimulated Electro- magnetic Emissions Plasma Line Ion Line

HF Antenna for Receiving Stimulated Electromagnetic Emissions from HAARP

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

ES and EM Wave Generation Optional Mode Conversion EM Pump Wave High Power EM or ES Wave Parametric Decay Optional Mode Conversion High Frequency EM or ES Wave Received EM Wave Low Frequency ES Wave Loss Possible Mode Conversion ? Low Frequency EM Wave DM 2D M 3D M UM BU M Pump In Situ Source: Upper Hybrid Waves In Situ Source: Electron Bernstein Modes Frequency (MHz) Relative Power (dB)

HAARP HF Transmitter Array 2.6 to 10 MHz, Up to 3.6 GW Effective Radiated Power

Heater Power Beam Angle Sweeping IA IA & EIC  Norin et al., 2009 observed the IA emission lines f 1 and f 2 due to Simulated Brillouin Scatter;  Bernhardt et al.,2009 observed IA lines f 1 and 2010 observed IA line f 1 and EIC lines f 3 ;  Bernhardt, P. A., C. A. Selcher, and S. Kowtha (2011), Electron and ion Bernstein waves excited in the ionosphere by high power EM waves at the second harmonic of the electron cyclotron frequency, Geophys. Res. Lett., 38, L19107, doi: /2011GL  The experiment conducted at HAARP in July, 2010 aims to look more thoroughly at a broader range of heater beam angle effects on IA and EIC waves generated by MSBS (Fu, Scales, Bernhardt 2011). I: Vertical beam (0 o,0 o ) II: Zenith beam (14 o,202 o ) (28 o, 202 o ) (28 o, 22 o ) Vertical Magnetic Zenith 11

Generalized MSBS matching conditions -f 4 -f 3 -f 2 -f 1 Reflection Upper hybrid [Bernhardt, 2009 ] f 1 - IA at reflection region; f 2 - IA at upper hybrid; f 3 - EIC at reflection region; f 4 - EIC at upper hybrid; 12

-180 Hz-120 Hz120 Hz180 Hz Stimulated Brillouin Scatter with Ion Acoustic Wave Generation is Simple EM1 IA1 EM2 SBS-1 B Pump SBS-1 f IA1  = 0

B Brillouin Scattering of the 4.5 MHz HAARP Vertical Beam in the Ionosphere

SBS with EIC Generation Yields Ion Mass Offset Frequency (Hz) Radio Beam Angel with B (  ) B  f EIC-1 f IA Azimuth 16.3 Zenith m i = e B/f EIC = m[O + ] f EIC-1 f IA Hz-120 Hz120 Hz180 Hz

Set II : Experimental Results for 4.1 MHz, O-mode Full Power, UT 04:15:00-04:60:00,07/22/2010 (Haiyang Fu, Virginia Tech) The IA lines f 1 =10~12 Hz is stronger close to the magnetic zenith The IA lines f 2 =24~26 Hz appears for ZA=28 o, AZ=202 o The EIC lines f 3 =50~52 appears for ZA=28 o, AZ=202 o The newly observed f 4 =70~72 appears for ZA=28 o, AZ=202 o f 1 =10~12 Hz; f 2 =24~26 Hz; f 3 =50~52 Hz; f 4 =70~72 Hz; 16

Stimulated Ion Bernstein (SIB) Generation by Tuning to the Second Electron Gyro Frequency EM 0 EB 0 FAI IB 1 EB 1 EM 1 FAI SIB1 IB 2 EB 2 EM 2 FAI SIB2 IB 3 EB 3 EM 3 FAI SIB3

Stimulated Ion Bernstein Waves with f 0 = 2 f ce HF Tuned to 2 nd 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 Wave Electrostatic Ion Cyclotron Wave Downshifted EM Wave Coupling of EIC wave to ULF EM Mode on Field Aligned Irregularities –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 Transmitter ULF Receiver HF Receiver

HAARP Array Generates a Hollow Beam Antenna Gain (dB)

22 Artificial Ionospheric Layers Created by the HAARP Transmitter HF Twisted Beam Layer 1 Layer 2 Frequency (MHz) Altitude (km) Objectives –Form Stable Plasma Layer –Open Artificial Propagation Path Progress –Demonstrated Twisted Beam –Formed Layer Lasting 5 Minutes –4 th Harmonic Resonance –Cyclotron Resonance Theory

23 SEE Near the 4 th Gyro Harmonic and Artificial Layers 25 March :53:00 UT 25 March :51:30 UT Layer Produced for 4.5 Minutes

03:32: Seconds 3.2 MHz +50 kHz -50 kHz -100 kHz 26 August 2011 SEE 03:32 UT

27 August 2011 SEE 00:04 UT Seconds 6.1 MHz +100 kHz +200 kHz +300 kHz -300 kHz -200 kHz -100 kHz 00:04:00

HF SEE Receiver Use Conclusions Simple New Experiments for HAARP 4 th 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