This document discusses different types of x-ray tubes, including their components and advancements. It begins with early Crookes tubes that had unreliable anodes made of aluminum. It then describes Coolidge tubes, which had improved thermionic emission and evacuated glass envelopes, allowing for more stable x-ray production. More advanced rotating anode x-ray tubes are discussed next, featuring molybdenum anode stems and dual tungsten-thorium filaments, providing larger output. The document also briefly covers stationary anode, grid controlled, and modern metal ceramic x-ray tubes which offer longer life and reduced off-focus radiation.

1. BRAINWARE
UNIVERSITY
Name- Anwesa Sardar
Student code- BWU/BRI/20/012
Semester- 3rd
Subject Name- Contrast and special radiography
procedures
Subject code- BMRIT 304
Topic name- X-ray tubes their types and advancements

2. CONTENTS
Introduction
Crookes tube and Coolidge Tube
Stationary anode X-ray tube and Rotating anode X-ray tube
Grid controlled X-ray tube and metal ceramic X-ray tube

3. INTRODUCTION
X-ray tube is a tube which is air evacuated and produce X- rays.
It mainly produce and attract electrons.
It’s basic principle is High voltage across anode and cathode, emitted electrons and interact
and produce X-rays.
Types: According to cathode: a) Cold cathode tubes(Crookes tube)
b)Hot cathode tubes (all other types)
According to anode: a) Stationary anode X-ray tube
b) Rotating anode X-ray tube
c)Grid controlled X-ray tube
d)Metal ceramic X-ray tube

4. CROOKES TUBE: Invented by William Crookes;
Used till 1920.
 Operation: High speed electron strike anode;
100 kv DC voltage between across cathode and
anode.
 Anode and cathode made up of Al.
 Disadvantages: 1.Unreliable
2. Over-heating problem
COOLIDGE TUBE: Improved by William
Coolidge;
 Characteristics: 1.High vacuum
2. Thermionic emission
 Tube envelope: 1.Made of Borosilicate(Pyrex)
2.Internal pressure 10^-8
mmHg
 Anode and cathode made up of Tungsten.
 Operation : X-ray produced by Bremsstrahlung
and characteristics method
 Advantages: Stability

5. ROTATING ANODE X-RAY TUBE: This is an
improvement of Coolidge Tube.
 Highly evacuated; Internal pressure 10^-8 mmHg
 Anode stem- Molybdenum; high melting point (2620°C)
 Rotor- copper and iron (Rotates 3000-9000 rpm)
 Focusing cup- effectiveness depend upon Shape, size etc.
 Filament – Dual; 90%tungsten & 10% thorium
 Advantage: Larger in size.
STATIONARY ANODE X-RAY TUBE: Anode and
cathode are kept in a evacuated glass envelope.
 The cathode consist of a tungsten filament; when it
hitted to white light, it emits electron.
 The anode is made up of copper block.
 Anode angle is usually 15-20 degree.

6. GRID CONTROLLED X-RAY TUBE: It has three
electrodes – Anode, cathode and focusing cup.
 The grid is electrically negative
 Since the cup and filament are close together, the
voltage necessary to cut off the tube current is not very
large.
METAL CERAMIC X-RAY TUBE: It is a high performance X
ray tube introduced by Philips Medical System.
 Tube has a metal casing and ceramic insulators.
 Aluminum oxide is a commonly used ceramic insulator.
 Three ceramic insulator are used.
Advantages: 1.Longer tube life
2.Lesser off-focus radiation.