DEFINITION, XRAY CONSTRUCTION, PRODUCTION, PROPERTIES, APPLICATION

1. X-RAYS
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2. INTRODUCTION
• X-RAY WHERE DISCOVERED BY RONTGEN IN 1895.
• IN THE ELECTROMAGNETIC SPECTRUM THE WAVES OF
WAVELENGTH BETWEEN 100 NM TO 0.01 PM (10 NM TO
0.01NM) .
• WHEN A SOLID TARGET (SOLID COPPER AND TUNGSTEN) IS
BOMBARDED WITH ELECTRONS WHOSE  KINETIC
ENERGIES ARE IN THE KILO ELECTRON VOLT RANGE
ELECTROMAGNETIC RADIATIONS CALLED X RAYS ARE
EMITTED. 17-09-2022
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3. X RAY PRODUCTION
E1
E2
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4. • THE COMMON DEVICE WHICH IS USED TO PRODUCE X-RAY IS CALLED AS
COOLIDGE TUBE
• COOLIDGE TUBE IS MADE UP BY GLASS BULB
• THE COOLIDGE TUBE IS CONNECTED WITH TWO ELECTRODES
• CATHODE IN THE FORM OF FILAMENT &
• ANODE IN THE FORM OF TARGET METAL
• CATHODE IS CONNECTED TO LOW TENSION BATTERY (L.T)
• TWO ELECTRO MAGNETIC FIELD PLATE E1 & E2 ARRANGED ON EITHER SIDE OF
CATHODE  CONTROLS THE ACCELERATION OF CATHODE RAYS EMITTED BY
FILAMENT
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5. • WHEN A VOLTAGE IS PRODUCED ACROSS THE ELECTRODES, THE
CATHODE RAYS ARE EMMITED AND THEY HIT THE TARGET  MADE UP
BY MOLYBDENUM/COPPER/TUNGSTEN
• THE TARGET METAL IS HELD AT AN ANGLE OF 45 DEGREE IN THE PATH
OF RAYS
• THUS X-RAYS ARE PRODUCED INVISIBLE
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6. • SHOWS IN GRAPH – IN MOLYBDENUM  35 KEV ELECTRONS  PRODUCED
WAVELENGTH IN SPECTRUM OF THE X-RAY  SO THIS GRAPH IS CALLED X-
RAYS SPECTRUM
• THE CONTINUOUS CURVE IN THE GRAPH IS CALLED CONTINUOUS X-RAY
SPECTRUM
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7. • CONSIDER AN ELECTRONS OF INITIAL KINETIC ENERGY K0 THAT COLLIDES WITH
ONE OF THE TARGET ATOMS
• THE ELECTRONS MAY LOSE AN AMOUNT OF ENERGY ∆K & PRODUCED X-RAYS
PHOTON
• THE SCATTERED ELECTRONS  ENERGY IS LESS THAN K0 MAY HAVE A SECOND
COLLISION WITH A TARGET ATOM  GENERATING A SECOND PHOTON
• IN THIS MANNER THEY GO ON LOSING ENERGY DURING MULTIPLE COLLISION &
EMITS X-RAYS OF DIFFERENT FREQUENCIES
• ALL THE PHOTONS GENERATED BY THESE COLLISIONS FORM PART OF THE
CONTINUOUS X-RAY SPECTRUM
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8. • IF ONE OR MORE ELECTRONS EXPERIENCES HEAD ON COLLISION
WITH AN ATOM OF THE ANODE  ITS TOTAL KINETIC ENERGY
COMPLETELY GETS CONVERTED INTO X-RAYS & HENCE X-RAYS OF
MAXIMUM FREQUENCY EMITTED
• THE MINIMUM POSSIBLE X-RAYS WAVELENGTH IS ACCORDING TO
PLANCK FORMULA : K = HF = H (C/Λ)
• Λ = HC/K (CUT OFF WAVELENGTH)
• Λ = WAVELENGTH, F = FREQUENCY , C = SPEED OF LIGHT
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9. PROPERTIES OF X-RAYS
• THEY ARE INVISIBLE TO HUMANS
• THEY ARE PROPAGATE IN STRAIGHT LINES IN FREE SPACE
• THEY ARE TRAVEL AT A SPEED OF LIGHT
• THEY AFFECT PHOTOGRAPHIC PLATE
• THEY STIMULATE FLUORESCENCE & PHOSPHORESCENCE IN SOME MATERIAL
• THEY ARE CAPABLE OF IONIZING GASES & CHANGING THE ELCTRICAL
PROPERTIES OF SOME LIQUIDS & SOLIDS
• IN SPECIAL CASES THEY ARE REFLECTED, DIFFRACTED, REFRACTED & POLARIZED
AS IS LIGHT
• THEY CONSIST OF TRANSVERSE ELECTROMAGNETIC VIBRATIONS AS DOES
LIGHT
• THEY HAVE ENERGIES BETWEEN 1 KEV & 50 MEV
• THEY CANNOT FOCUSED BY LENS
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10. APPLICATIONS OF X-RAY
• THE MAIN USE OF X-RAY IS IN MEDICINE  DOCTORS USE X-RAYS TO
DETECT CANCER, ULCERS, KIDNEY STONES, FRACTURES & OTHER
ABNORMALITIES. X-RAYS ARE HELPS DENTISTS TO DETECT DISEASES
OF THE TEETH
• OTHER USES ARE IN INDUSTRY, AT AIRPORTS TO CHECK CUSTOMERS &
LAGGAGE
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