X-RAY SPECTRA

TOPIC:X-RAY SPECTRA
SUBJECT:#Atomic_and_Nuclear_Physics
#xray #typesofxray #xrayspectra

1. X-Ray spectra Atomic And M olecular Physics Presented by :NUMAN USAMA KHAN

2. X-Ray: X-rays are a very energetic form of electromagnetic radiation that can be used to take images of the human body . X-rays are roughly classified into soft X-rays and hard X-rays.  Soft X-rays have (short wavelengths of about 10 nanometers). Hard X-rays have (wavelengths of about 100 picometer ).

3. History of X-rays: X-rays were discovered in 1895 by Wilhelm Conrad Röentgen . For this discovery, Röentgen was awarded the very first  Nobel Prize in physics in 1901.

4. X-Ray spectra: X-ray output plotted on graph called spectra. X ray spectra are continuous. K-line and L-line are called characteristics.

5. C ontinuous and characteristic X-ray spectra: The spectrum from an X-ray tube contains two distinct parts. Continuous X-ray spectra. Characteristic X-ray spectra.

6. Continuous X-ray spectra: It consists of radiations of all possible wavelengths, from a certain lower limit to higher values continuously, as in the case of visible light.

7. Continuous X-ray spectra: Initial energy = Final energy = Change in energy =  h ν = hc / λ =    =  

8. Continuous X-ray spectra: eV = h ν max   = hc / λ min λ min  = hc / eV Putting the values of Planck's constant, speed of light and the charge of the electron. λ min   = 12400/V A

9. Continuous X-ray spectra:

10.  Characteristic X-ray spectra: It consists of definite, well defined wavelengths superimposed on the continuous spectrum. These spectral lines generally occur in the form of small groups and are characteristic of the material of the target .

11. Characteristic X-ray spectra: In this case fast moving electron knock out the tightly bound electrons even from the inner most shells (like K, L shells) of the atom . when the fast moving electrons knock off one electron from K-Shell and the vacancy is filled by the nearby electron from the L shell. During this transition, the energy difference is radiated in the form of X-rays of very small wave length. This corresponds to K α   line of the series . The frequency ν 1  of this line is given by the relation (E K  - E L ) = hν 1 If electron from M shell jumps to the K shell, it gives out K β  line and so on.

12. Characteristic X-ray spectra: If an electron jumps from the M-Shell to the vacant state in L-Shell, it contributes L α  line If the vacancy in L-Shell is filled up by an electron of N shell, it contributes L β line and so on. The frequency of radiation depends upon the target material. The X-ray spectra consists of sharp lines and is the characteristic of target material. Hence this spectra is known as characteristic spectra.

13. Characteristic X-ray spectra: When we draw K α   line, K β   line and L α  line . We get the following curve.

14. Continuous and characteristic X-ray spectra :