Question

1. (a) With the aid of a labeled sketch, describe an apparatus for the generation of x-rays.

(b) With the aid of labeled sketches, describe the three primary physical mechanisms for the absorption of x-rays in solids.

(c) Make a sketch of a typical x-ray spectrum generated by a hospital apparatus, labeling three primary features of the spectrum.

(d) For an x-ray apparatus containing a molybdenum target of atomic number, z = 42:

(i) What is the wavelength for the shortest characteristic x-ray emission? You may use the relationship for the energy of a quantum state, ???? = ?13.6???? (?? ? 1) 2 ?? 2 ? where z is the atomic number of an element, n is the quantum state number where n = 1 represents the ground state.

(ii) Where the accelerating potential is 60 keV, what is the minimum wavelength of emission?

(iii) If the accelerating potential is increased, explain whether the wavelengths of the K? and K? lines increase, decrease, or remain the same?

Answer 1

1 )

the generation of x-rays

here the following sketch explains the generation of x-rays  

x rays are nothing but the accelerated electrons are having kinetic energy is called as x-rays.

2 )

three major parts involve in the absorption of x - rays

i ) pair production

ii ) scattering

iii ) photo electric effect

c )

a typical x-ray spectrum generated by a hospital apparatus

they are dense matter,

types can be used is hard and soft x ray so f 1 to 100 A^o

d )

i )

E_n = -13.6 x 42² / 1

E_n = - 23990.4 eV

E = h

= h C / E

= 6.627 x 10^-34 x 3 x 10⁸ / 23990.4 x 1.6 x 10^-19

= 5.179 x 10^-11 m

= 51.79 x 10^-10 m

= 51.79 A^o

ii )

= h C / eV

= 6.627 x 10^-34 x 3 x 10⁸ / 1.6 x 10^-19 x 60 x 10³

= 2.07 x 10^-11 m

= 20.77x 10^-10 m

= 20.7 A^o

iii)

accelerated PE increased

if K and K are decreases

from = h C / eV

wavelength is decreases.