Characteristic and-bremsstrahlung-x-rays

RT

1. Characteristic and Bremsstrahlung X-rays

2. Characteristic x-rays result when the interaction is sufficiently violent to ionize the target atom through removal of an inner shell electron and an outer electron fills the vacancy.

3. Only k-characteristic x-rays are useful in imaging

4. Bremsstrahlung is a G erman word that mean “slowed down radiation “. These are x-rays that results from braking of projectile electrons by the nucleus. Electrons are slowed and direction is changed by the nuclear force field.

5. - In diagnostic range, most x-rays are bremsstrahlung x-rays.

6. Approximately 99% of kinetic energy of projectile electrons is converted to heat Only one percent of the electrons produced in the cathode is converted to x-rays

7. The efficiency of x-ray production increases with increasing kVp At 60 kVp only 0.5% of electrons are converted to x-rays At 100 kVp only 1% is converted to x-rays At 20 MVp 70% is converted to x-rays

8. At 65 kVp , no useful characteristic x-rays are produced, therefore all x-rays produced are bremsstrahlung. At 100 kVp , 15% of the x-ray beam is characteristic and the other 95 % is bremmstrahlung .