Homework SourseThe smallest dimension that can be resolved by an electron m
The smallest dimension that can be resolved by an electron microscope is equal to the de Broglie wavelength of its electrons. What accelerating voltage would be required for electrons to have the same resolving power as could be obtained using 100 keV gamma rays?
The smallest dimension that can be resolved by an electron microscope is equal to the de Broglie wavelength of its electrons. What accelerating voltage would be required for electrons to have the same resolving power as could be obtained using 100 keV gamma rays?
Solution
The voltage required to accelerate an electron to the same energy as the 100 keV gamma ray is the accelerating voltage, and the energy of the particle gives the resolving power. The higher the energy, the greater is the resolving power.
Also, an electron volt (1 eV), by definition, is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electrostatic potential difference of one volt.
So for an electron to gain energy equal to 100 keV, we need 100 kV.
So the accelerating voltage is 105 volts.
