X-Ray Fluorescence Analytical Techniques - CNSTN : Centre ...

I. (The Photon Concept)
EXERCICES
An FM radio station of frequency 107.7 MHz puts out a signal of 50,00 W. How many
photons per second are emitted?
II. (X-Ray Production)
III.
IV.
18 kV accelerating voltage is applied across an X-ray tube. Calculate:
i. The velocity of the fastest electron striking the target,
ii. The minimum wavelength in the continuous spectrum of X-rays produced.
Mass of electron = 9 x 10 -31 kg;
Charge on electron = 1.6 x 10 -19 C;
h = 6.6 x 10 -34 Js;
c = 3 x 10 8 m/s.
An X-ray tube is operated with an anode potential of 10 kV and an anode current of 15
mA. Calculate
i. The number of electrons hitting the anode per second,
ii. The rate of production of heat at the anode stating any assumptions made and
iii. The frequency of the emitted X-ray photon of maximum energy.
e = 1.6 x 10 -19 C h = 6.6 x 10 -34 J.s
(a) What is the threshold frequency for the photoelectric effect on lithium (We = 2.9
eV)?
(b) What is the stopping potential if the wavelength of the incident light is 400 nm?
V. (The Photoelectric Effect)
A television tube operates at 20,000 V. What is λmin for the continuous x-ray spectrum
produced when the electrons hit the phosphor?
VI. (The Compton Effect)