Fast digitizing oscilloscopes, pulse

The measurement system employed to observe PCA signals is shown in Fig. 2. The N2 laser with a pulse width of Ins and a spot size of 3x5 mm irradiated the surface of the silicon wafer sample to generate excess carriers. The sample placed apart om the aperture of the WG-10 waveguide by several millimeter was irradiated by the mm-wave of 100 GHz. PCA signals as photoconductivity variation detected with the diode from the reflected mm-wave were observed directly using the fast digitalizing oscilloscope (Lecroy, 6120) with 5G-sampling and 350 MHz -bandwidth. 

The excitation source used for PA experiments discussed here was a Nd YAG and dye laser combination, producing 12 nsec pulses at 2.2eV. The change in sample transmission, AT was obtained either by integrating the detector signal with a lock-in amplifier or, for time-resolved measurements, by using a fast digital oscilloscope [14]. 

Multichannel Scalers ( Multiscalers ) are the photon-counting equivalent of a digital oscilloscope or a transient recorder. They record the input pulses directly into a large number of consecutive channels of a fast memory. The technical principles behind multiscalers are described below. 

The time-resolved PL requires additional instrumentation for capturing the evolution of intensity, such as a fast CCD or a streak camera for detecting very fast transients. However, a simple digital oscilloscope in combination with a pulsed laser may be very useful for measuring the defect-related PL decays in ZnO, which by their very nature are slow and are typically in the range from a few nanoseconds to milliseconds. 

The transducer in a lOF mass spectrometer is usually an electron multiplier whose output is displayed on the vertical deflection plates of an oscilloscope and I he horizontal sweep is synchronized with the acceler ator pulses an essentially instantaneous display of the mass spectrum appears on the oscilloscope screen. Be cause typical flight times are in the micro.second range digital data acquisition requires extremely fast elec... 

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