Chapter 28, Problem 1CQ

To determine

The effect of the angle for a particular order or constructive interference from a crystal, when the photon energy of an x-ray beam is increasing.

Answer to Problem 1CQ

When the photon energy of the x ray beam is increasing then the angle for the particular order will decreases.

Explanation of Solution

Given info: The photon energy of an x-ray beam is increasing.

Explanation:

Write the expression for the Bragg condition.

$n\lambda =2d\sin {\theta }_m$

Here,

$\lambda$ is the wavelength

$d$ is the spacing between the planes

${\theta }_m$ is the angle of incidence

Write the expression for the energy of the x ray crystal.

$E=h\frac{c}{\lambda }$

Here,

$E$ is the energy

$h$ is the planks constant

$\lambda$ is the wavelength

$c$ is the velocity of light

When the energy of the photon increase, the wavelength of the photon will decrease.

From the Bragg condition, the wavelength of the photon is related to the angle of incidence ${\theta }_m$.

Therefore, the angle for a particular order or constructive interference from the crystal decreases, when the photon energy of an x-ray beam increases.

Conclusion:

Therefore, the angle for a particular order or constructive interference from the crystal decreases, when the photon energy of an x-ray beam increases.