Accelerators, electric

In time-of-flight (TOF) mass spectrometers, a pulse of ions is accelerated electrically at zero time. Having attained a maximum velocity, the ions drift along the flight tube of the analyzer. The times of arrival of ions at a detector are noted. 

Figure 7 is a graphic description of the kinetic energy required by a deuteron to produce D-D, D-T, and D-helium-3 nuclear reactions. The bottom of the chart depicts the required deuteron kinetic energy level in thousands of electron volts. The x-axis coordinate is labeled from 10° to 103 kilo-electronvolts. The y axis is labeled in terms of the nuclear reaction cross section. Three types of nuclear reaction curves are depicted. Note that each curve rises to a maximum and then decreases in value. The D-D curve is shown with its maximum value at about 1000 keV. Considering the use of a typical ion accelerator, electric potentials ranging from about 10 to 106 keV are used. 

Instrumented punches and dies, which enable online measurement of forces on the punch and relative displacement or acceleration, electrical resistance, and acoustic release as well as measurement of die wall forces, are special tools used exclusively in research they are discussed in a separate chapter. 

Probe measurements indicate the existence of an accelerating electric field for electrons near the collector which leads to the formation of the ball. 

In 1888, Heinrich Hertz detected radio waves produced by accelerated electric charges in a spark, as predicted by Maxwell s equations. This convinced physicists that light is indeed an electromagnetic wave. 

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