scholarly journals The Peoples Republic of China High-Frequency Gravitational Wave Research Program

2009 ◽  
Author(s):  
Robert M. L. Baker ◽  
Glen A. Robertson
Keyword(s):  
Gravitational Wave ◽  
Research Program ◽  
High Frequency ◽  
Republic Of China ◽  
Wave Research

scholarly journals Gravitational wave detectors with broadband high frequency sensitivity

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael A. Page ◽  
Maxim Goryachev ◽  
Haixing Miao ◽  
Yanbei Chen ◽  
Yiqiu Ma ◽  
...  
Keyword(s):  
Gravitational Wave ◽  
White Light ◽  
High Frequency ◽  
Phononic Crystal ◽  
Optical Power ◽  
Light Signal ◽  
Acoustic Cavity ◽  
Silicon Nitride Membrane ◽  
Gravitational Wave Detectors ◽  
Crystal Quartz

AbstractGravitational waves from the neutron star coalescence GW170817 were observed from the inspiral, but not the high frequency postmerger nuclear matter motion. Optomechanical white light signal recycling has been proposed for achieving broadband sensitivity in gravitational wave detectors, but has been reliant on development of suitable ultra-low loss mechanical components. Here we show demonstrated optomechanical resonators that meet loss requirements for a white light signal recycling interferometer with strain sensitivity below 10−24 Hz−1/2 at a few kHz. Experimental data for two resonators are combined with analytic models of interferometers similar to LIGO to demonstrate enhancement across a broader band of frequencies versus dual-recycled Fabry-Perot Michelson detectors. Candidate resonators are a silicon nitride membrane acoustically isolated by a phononic crystal, and a single-crystal quartz acoustic cavity. Optical power requirements favour the membrane resonator, while thermal noise performance favours the quartz resonator. Both could be implemented as add-on components to existing detectors.

scholarly journals HF-induced airglow at magnetic zenith: theoretical considerations

2005 ◽  
Vol 23 (1) ◽  
pp. 47-53 ◽  
Author(s):  
E. V. Mishin ◽  
W. J. Burke ◽  
T. Pedersen
Keyword(s):  
Research Program ◽  
Acoustic Waves ◽  
High Frequency ◽  
Theoretical Framework ◽  
Green Line ◽  
Ion Acoustic Waves ◽  
Heating Facility ◽  
Ion Acoustic ◽  
Theoretical Considerations ◽  
Magnetic Zenith

Abstract. Observations of airglow at 630nm (red line) and 557.7nm (green line) during HF modification experiments at the High Frequency Active Auroral Research Program (HAARP) heating facility are analyzed. We propose a theoretical framework for understanding the generation of Langmuir and ion acoustic waves during magnetic zenith injections. We show that observations of HF-induced airglow in an underdense ionosphere as well as a decrease in the height of the emitting volume are consistent with this scenario.

On the conversion of electric oscillations into continuous currents by means of a vacuum valve.

1905 ◽  
Vol 74 (497-506) ◽  
pp. 476-487 ◽  
Author(s):  
John Ambrose Fleming
Keyword(s):  
High Frequency ◽  
Quantitative Research ◽  
Alternating Current ◽  
Heating Effect ◽  
Very High Frequency ◽  
Magnetizing Force ◽  
Wave Research ◽  
Very High ◽  
Electric Waves ◽  
Electric Oscillation

An electric oscillation being an alternating current of very high frequency, cannot directly affect an ordinary movable coil or movable needle galvanometer. Appliances generally used for detecting electric waves or electric oscillations are, therefore, in fact, alternating current instruments, and must depend for their action upon some property which is independent of the direction of the current, such as the heating effect or magnetizing force. The coherer used in Hertzian wave research is not metrical, since the action is merely catastrophic or accidental, and bears no very definite relation to the energy of the oscillation which starts it. Even the demagnetising action of electric oscillations, though more definite in operation than the contact action at loose joints, is far from being all that is required for quantitative research.

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