Radio-frequency oscillator

The NMR-spectrum can be scanned either by changing the frequency of the radio-frequency oscillator or by changing the spacing of the energy levels while making a small change in the applied magnetic field. 

Fig. 3. Principle of linear accelerator (linac). Partially accelerated electrons from a source, such as a Cockcroft-Walton generator, arc further accelerated by stages as rhe electrons pass through radio-frequency cavities, powered by if oscillators. Each paiticle receives a small push as it passes from one cavity to the next until the final desired accelerated beam is produced Tile machine must be carefully synchronized CSG = Cockcroft-Walton generator, RFO = radio-frequency oscillator RFC = radio-frequency cavity...

For a spin whose chemical shift is exactly at the center of the spectral window, we call the pulse an on-resonance pulse because the pulse (or carrier ) frequency is exactly equal to the resonant frequency (precession frequency or Larmor frequency vG) of the spin. During the pulse, we can use the vector model to show the B field (the pulse) as stationary in the rotating frame of reference, because the x and y axes are rotating about the z axis at exactly the frequency of the pulse. The position of the B field in the x -y plane depends on the phase of the pulse, which is just the place in the sine function (0-360°) where the radio frequency oscillation starts at the beginning of the pulse. This can be controlled by the spectrometer and is written into the pulse sequence by the user ... 

The measurement is conducted by frequency modulating a diode laser by superimposing a radio frequency oscillation, Q, onto the diode injection current. The spectral output of a frequency modulated diode laser, shown at the top of Fig. 3, consists of a carrier frequency, a>c and side band frequencies, cOc H. When the laser is scanned through the wavelength of oxygen absorbance, the amount of light absorption, which is proportional to the gas concentration, is written into the side band frequencies by recording the difference in absorption between the two sidebands. 

Capacitive proximity switches sense distance to objects by detecting changes in the capacitance around it. A radio-frequency oscillator is connected to a metal plate or... 

EPR multiline signals were measured at 4.2-6.0 K with Varian E109 spectrometer equipped with an Oxford cryostat or a pair of finger type double dewars by 100 kHz magnetic field modulation. A cylindrical TE., mode cavity with ENDOR coils was used. ENDOR spectra were taken by iO KHz frequency modulation of radio frequency oscillation. Details are given in [3]. 

In the Dynamitron, a radio-frequency oscillator is capacity-coupled to a number of rectifier circuits that are wired in series. The fundamental... 

Radio Frequency Oscillation of a radio wave in the range of 3 kilohertz (3,000 cycles p>er second) to 300 gigahertz (300,000,000,000 cycles per second). 

The ideal radiator would be truly massless and employ no moving parts. Such a device was produced for a short time and was known as the ionophone. The operation depended on a small quartz tube, open at one end with the other connected to a Kanthal electrode. The electrode is connected to a radio frequency oscillator of high-voltage output causing ionic discharge to occur in the air within the quartz tube. See Fig. 3.66 (Borwick, 1994, 37). 

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