Under what condition Compton shift in wavelength is maximum? Elaborate your answer.

The Compton shift in wavelength is maximum when the scattering angle is 180 degrees. This is known as backscattering.

Let's break it down:

1. Compton scattering is the scattering of a photon by a charged particle, usually an electron. It results in a decrease in energy (increase in wavelength) of the photon, which is called the Compton shift.

2. The amount of energy lost by the photon (and thus the increase in wavelength) is directly related to the scattering angle (the angle at which the photon is deflected).

3. When the scattering angle is 0 degrees (i.e., the photon is not deflected at all), there is no Compton shift. The photon retains all its energy and its wavelength remains the same.

4. As the scattering angle increases, so does the Compton shift. The photon loses more and more energy, which translates into an increase in wavelength.

5. When the scattering angle is 180 degrees (i.e., the photon is deflected back in the direction it came from), the Compton shift is maximum. The photon loses the most energy, and its wavelength increases the most.

So, the condition under which the Compton shift in wavelength is maximum is when the scattering angle is 180 degrees.