Phenomenon of X-ray production and basic design of X-ray tube

1. X-ray Production And
Construction

2. CONTENT
INTRODUCTION
HISTORY OF DISCOVERY OF X-RAY
PROPERTIES OF X-RAY
PRODUCTION OF X-RAY
TYPES OF X-RAYS
X-RAY TUBE DESIGN AND CONSTRUCTION
CONCLUSION

3. INTRODUCTION
X-RAYS ARE FORM OF HIGH ENERGY ELECTROMAGNETIC
RADIATION AND PART OF ELECTROMAGNETIC SPECTRUM
WITH WAVELENGTH SHORTER THAN VISIBLE LIGHT . MOST
OF X-RAYS HAVE A WAVELENGTH RANGING FROM 0.03 TO 3
NANOMETER .

4. HISTORY OF DISCOVERY OF X-RAY
X-RAYS WERE DISCOVERED BY GERMAN PHYSICIST WILHELM
CONRAD ROENTGEN , ON 8th NOV 1895 . WHEN HE WAS
INVESTIGATING THE CONDUCTION OF ELECTRICITY
THROUGH GASES AT LOW PRESSURE IN GLASS TUBES .

5. PROPERTIES OF X-RAYS
• X-RAYS ARE ELECTROMAGNETIC RADIATION OF SHORTER
WAVELENGTH .
• THEY TRAVEL IN STRAIGHT LINE WITH A VELOCITY OF
LIGHT .
• X-RAYS PRODUCE CHEMICAL CHANGES IN SUBSTANCES
THROUGH WHICH THEY PASS .
• X-RAYS PENETRATE THROUGH SUBSTANCES THAT ARE
OPAQUE TO VISIBLE LIGHT .

6. PRODUCTION OF X-RAY
WHEN THE FAST MOVING ELECTRONS STOPPED BY THE
TARGET (ANODE) THE KINETIC ENERGY OF THE
ELECTRONS WILL BE CONVERTED INTO X-RAYS .
BASED ON THEIR WAY OF PRODUCTION , X-RAYS ARE OF
TWO TYPES :
(a)BREMSSTRAHLUNG RADIATION .
(b)CHARACTERISTIC X-RAYS .

7. BREMSSTRAHLUNG X-RAYS
THE BREMSSTRAHLUNG IS A GERMAN WORD MEANING
BREAKING RADIATION . THE ELECTRON WHILE PASSING
NEAR THE NUCLEUS MAY SUFFER A SUDDEN DEFLECTION
AND ACCELERATION BY THE ACTION OF COULOMB FORCES
OF ATTRACTION . AS A RESULT , THE ELECTRONS MAY LOSE
THEIR KINETIC ENERGY , IN THE FORM OF
BREMSSTRAHLUNG X-RAYS .

8. PROCESS OF PRODUCTION OF BREMSSTRAHLUNG X-RAYS

9. CHARACTERISTIC X-RAYS
ELECTRON INCIDENT ON A TARGET MAY PRODUCE CHARACTERISTIC
X-RAYS. AN ELECTRON WITH KINETIC ENEGY E0 MAY INTERACT WITH
THE ATOMS OF THE TARGET, BY EJECTING AN ORBITAL ELECTRON
FROM THE K SHELL. NOW, THERE IS VACANCY IN THE K SHELL AND
THE ATOM IS SAID TO BE IONIZED. THE OUTER ORBITAL ELECTRONS
(FROM M OR L SHELL) WILL FELL DOWN TO FILL THE VACANCY IN THE
K SHELL. IN DOING SO, THE DIFFERENCE IN BINDING ENERGY OF
THE TWO SHELLS IS IRRADIATED IN THE FORM OF X-RAY PHOTONS
WHICH ARE KNOWN AS CHARACTERISTIC X-RAYS.

10. PROCESS OF PRODUCTION OF CHARACTERISTIC X-RAYS

11. X-RAY TUBE DESIGN & CONSTRUCTION
X-RAY TUBE – IT IS ELECTRICAL DEVICE WHICH CONTAINS ALL
THE ESSENTIAL COMPONANTS REQUIRED FOR PRODUCTION OF
X-RAYS, WITH IN AN EVACUATED GLASS/METALLIC ENVELOPE.

12. COMPONENTS OF X-RAY TUBE
COMPONENTS OF X-RAY TUBE – THE X-RAY TUBE IS CONSISTS
OF FOLLOWING ELEMENTS :-
CATHODE
ANODE
FOCUSING-CUP
GLASS HOUSING

13. CATHODE
 CATHODE IS -VE TERMINAL OF AN X-RAY TUBE.
 IT IS CONSIST OF A FILAMENT (SOURCE OF e-), CONNECTIVE WIRES ( FOR POWER SUPPLY) &
A METALLIC FOCUSING CUP.
 THE W74 FILAMENT IS 0.2 cm IN DAIMETER & 1cm OR LESS IN LENGTH.
 ELECTRONS ARE PRODUCED FROM CATHODE BY “THERMOIONIC EMISSION”.
 SUPPLY OF CURRENT TO THE FILAMENT ∝ PRODUCTION OF ELECTRONS FROM FILAMENT
FILAMENT &
FOCUSING CUP

14. ANODE
 ANODE IS THE +VE TERMINAL AND SERVES AS TARGET FOR THE ELECTRONS EMMITED
FROM CATHODE
 ANODE SHOULD HAVE FOLLOWNG PROPERTIES :-
 HIGH ATOMIC NUMBER.
 HIGH MELTING POINT.
 HIGH SPECIFIC HEAT & THERMAL CONDUCTIVITY.
 LOW VAPOUR PRESSURE EVEN AT HIGH TEMPERATURE.
 CONVENIENT FOR MECHANICAL CONSTRUCTION.
TUNGSTEN IS THE METAL OF CHOICE FOR
ANODE BECAUSE OF IT’S HIGH ATOMIC
NUMBER (74) AND A HIGH MELTING POINT
ABOUT 3370ºC.
ANODE (ROTATING TYPE)

15. FOCUSING CUP
 THE FOCUSING CUP IS MADE UP OF MOLYBDENUM (MO).
 IT IS A METAL CUP IN WHICH THE CATHODE OF AN X-RAY TUBE IS
MOUNTED.
 THE CATHODE CUP CONTROLS THE WIDTH OF ELECTRON
DISTRIBUTION, DIRECT THE ELECTRONS TOWARDS THE TARGET.
FOCUSING CUP OF X-RAY
TUBE( WITH OTHER
COMPONENTS)

16. GLASS HOUSING
 THE ANODE & THE CATHODE ARE ENCLOSED IN A BOROSILICATE GLASS
ENVELOPE CONTAINING A VACUUM, BECAUSE GAS IN THE TUBE WILL PROVIDE
RESISTANCE TO THE ELECTRONS.
 FUNCTIONS OF GLASS HOUSING:-
 IT PROVIDES AN ATTACHMENT SURFACE FOR THE COLLIMATORS
 IT CONTAINS COOLING OIL FOR HEAT DISSIPATION
 IT SHIELDS AGAINST THE STRONG X-RAYS (INHERENT FILTERATION).
 IN ROATATING ANODE TYPE TUBE, IT CONTAINS ANODE ROTATION POWER
SOURCE.
GLASS HOUSING

17. CONCLUSION
THE QUALITY OF X-RAYS AND THE BASIC TUBE DESIGN AND
CONSTRUCTION ARE DEPENDS ON OUR NEEDS SUCH AS THE
QUALITY IMAGING, WORKLOAD AND DURABILIYY OF THE
INSTRUMENTS BEING USED. ALTHOUGH THE BASIC METHOD OF
PRODUCTION OF X-RAYS IS STIL SAME BUT SOME ADVANCEMENTS
AND MODIFICATION IN PRODUCTION OF X-RAYS AND INSTRUMENT
DESIGN HAS CAME INTO EXISTANCE FOR BETTER PERFORMANCE OF
THE X-RAY TUBE AND TO IMPROVE THE OF QUALITY IMAGES TO
BRING PRECESION IN RADIODAIGNOSIS.

18. THANK-YOU