X - RAX

 X-Ray

X –rays was discovered by William Roentgen in 1895. It is the inverse of photo electric effect.

X – rays is a stream of particles that is emitted when fast accelerating or moving electrons collide with a tungsten target.

PRODUCTION OF X – RAYS

X-rays are produced when electrons produced by thermionic emission are accelerated through high voltage and are focus onto a tungsten target. The accelerated electrons strike the tungsten target, transform into heat and emit radiation called x-rays.        
                                                                                         

Diagram of x—ray tube

Function of parts of x-ray tube

1. Filament / cathode: it produces electron by thermionic emission.
2. Focusing cathode: it helps to focus the electron onto the tungsten target of high melting point.
3. Cooling fins: it helps to cool the copper anode and minimise the temperature of the tube.
4. High voltage:  it helps to accelerate the electrons onto the tungsten target.
5. Copper anode:

ENERGY TRANSFORMATION DURING X-RAY PRODUCTION

During x-ray production, energy transformation takes place. The energy transformation that takes place is explained thus:

Electrical energy is transformed into heat / thermal energy of the thermionic electron and the thermal energy is converted into kinetic / mechanical energy of the accelerated electron and electromagnetic radiation.

Types of x-rays

X-rays are classified into two types based on their wavelengths and power of penetration:

1. Hard x-rays: These types of x-rays have high penetrating power and short wavelengths. It is produced by increasing the potential difference between the cathode and the anode of the tube. At high voltage, the electrons accelerate faster with more kinetic energy and collide with the tungsten target with high energy to produce hard x-ray.
2. Soft x-ray: These types of x-rays have lower penetrating power and long wavelengths. It is produced by lowering the potential difference between the cathode and the anode. At low voltage, the thermionic electrons move slowly with lower kinetic energy and collide with the tungsten target with little energy which produces soft x-rays.

HARDNESS OF X-RAYS

The hardness of x-rays is a measure of the strength or the penetrating power of the x-ray.

INTENSITY OF X-RAY

Intensity of x-ray is the energy radiated per unit time per unit area by the x-ray. The intensity of x-ray is determined by the current of the hot filament which also depends on the temperature of the filament.

DIFFERENCES BETWEEN HARD X-RAYS AND SOFT X-RAYS

Hard x – rays                                                      soft x – rays

1. It is produced by high target voltage       It is produced by low target voltage.
2. They have short wavelength                      they have long wavelength.
3. They have high penetrating power          they have low penetrating power.
4. They are produced by high voltage          they are produced by low voltage.

PROPERTIES OF X-RAYS

X-rays have the following properties or characteristics:

1. X – Rays are electromagnetic in nature.
2. X-rays are undeflected by either magnetic or electric field.
3. X – Rays have short wavelengths.
4. X – Rays have high penetrating power.
5. X – Rays are neutral particles.
6. X – Rays poses energy.
7. X – Rays affect photographic plates and paper. It makes them to fog.
8. X – Rays causes ionization of gas atoms.
9. X- Rays undergo reflection, refraction and diffraction.
10. X – Rays causes glass and other materials to fluorescent or give out their own light.

Applications or uses of x – rays

1. X – rays are used to detect alteration to art work.
2. X – rays are used to detect hidden weapons.
3. X – rays are used to detect hidden cracks in materials.
4. X – rays are used in crystallography. To study the internal structure of crystal.
5. X – rays are used in medicine to study nature of fracture, in the diagnose and treatment of cancer, ulcer.
6. X – Rays are used in agriculture to kill germs.
7. X – Rays are used in radiotherapy.
8. X – Rays are used to detect fault in welding work.

DANGER OR HAZARDS OF OVER – EXPOSURE TO X – RAYS

It is dangerous to over - expose oneself to x –rays. The following are the dangers associated with the overexposure:

1. It causes skin bun (ii) it cause cataracts (iii) cancer of the blood called leukemia. (iv) Tissue damage. (v) Change in genetic structure called mutation.

PRECAUTION TO BE TAKEN WHEN USING X – RAYS

The following precautions need be taken when handling x – rays:

1. Wear lab coat when handling x – rays gadget.
2. Go for regular and periodic medical checkup.
3. Use Gm counter as to know the quantity of x – rays you dealing with.