Radio-quiet neutron star Radio-quiet neutron star A radio-quiet neutron star is a neutron star that does not seem to emit radio emissions, but is still visible to Earth through electromagnetic radiation at other parts of the spectrum, particularly x-rays and gamma rays. Most detected neutron stars are pulsars, and emit radio-frequency electromagnetic radiation. About 700 radio pulsars are listed in the Princeton catalog, and all but one emit radio waves at the 400 MHz and 1400 MHz frequencies. That exception is Geminga, which is radio quiet at frequencies above 100 MHz, but is a strong emitter of X-rays and gamma rays. In all,
Plasma diagnostics modification of the laser-induced fluorescence technique. In this approach the upper level is excited by absorbing two photons and registering the resulting emission from the excited state. The advantage of this approach is that the registered light from the fluorescence is with a different wavelength from the exciting laser beam, which leads to improved signal to noise ratio. The optical diagnostics above measure line radiation from atoms. Alternatively, the effects of free charges on electromagnetic radiation can be used as a diagnostic. In magnetized plasmas, electrons will gyrate around magnetic field lines and emit cyclotron radiation. The frequency of the