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X-ray Technology

What is radiation?

X-ray system

  • Ionized radiation : Radiation causes ionization shooting orbital electron of atom outward

        Alpha particle, beta particle, neutron, electron, proton, gamma ray, X-ray etc.

 
  • Non-ionizing radiation : Radiation does not cause ionization

        Sunray, ultraviolet, infrared ray, visible ray etc.

 

What is X-ray?

  1. Nov. 5th 1895, W.C Roentgen found platinum cyanide barium painted paper is fluorescing from a distance during cathode ray experiment.
  2. He confirmed fluorescence mechanism is occurred by unknown ray while experiment with shielded cathode. He named it X-ray, announced thesis and awarded as the first Nobel Prize in Physics in 1901.
  3. At that time, it was utilized for Radiography simply penetrating surface.
  4. X-ray is now being widely used to diagnose characteristic and structure of material by diffraction, fluorescence and total reflection.
 
 

 

X-ray system

  • Electronic wave at 10-11~10-9m wavelength
  • Strong penetrating power into material surface
  • Utilized as non-destructive inspection such as medical equipment and
    industrial inspection system by using differentiation of penetrating power

 

Characteristic of X-ray

  1. Photograph action
  2. Fluorescence effect – make fluorescence when expose to ZnS, CdS, NaI etc.
  3. Ionization effect
  4. High rate penetration
  5. Same speed as light in vacuum
  6. Diffraction
  7. The refraction rate is almost 1.

 

Principle of X-ray Generation

Characteristic X-ray : Accelerated electron interacts with orbital electron and outside electron is transferred.
Electric wave is emitted as the difference of energy and the wave is called characteristic X-ray.

Continuous X-ray : Accelerated electron is decelerated buy the Coulomb Potential Energy around a nucleus, and emits radiation as much as decelerated difference. This is called bremsstrahlung ray or continuous X-ray.

 

X-ray System

X-ray system

X-ray Tube Generates X-ray
Table Moves sample in radiation equipment
Detector Converts transmission electron to visible light
CCD Camera Converts visible light from Detector to digital data
Controller Controls image and entire system of inspection system
Shield cabinet Shields radiation

 

Advantage of X-ray Inspection

X-ray system

X-ray system

  • No need Vacuum unlike SEM

  • Non-destructive inspection by using high penetrating power
    No need preprocessing(cutting, destroying) for inside inspection
  • Simple inspection process and easy to operate

 

See more for SEC X-ray

 

Types of X-ray Tube

Open Tube

Vacuum condition can be built from pump installed system
Higher magnification and resolution than Closed tube
Consumables(Target, Filament etc.) are replaceable and semi-permanent

Representative models are X-eye SF160FCT and X-eye 7000B.

Closed Tube

Vacuum condition sealed during manufacturing process
Unable to replace inside components
Change every set if broken

Representative models are X-eye 5100F and X-eye 5000N.

 

Types of X-ray Detector

X-ray system

  • X-ray system is converted to visible light when absorbed by Scintillator through Al
  • Input window (high transmission and low diffusion of X-ray system)
  • Visible light is converted to photoelectron image by Photocathode
  • Photoelectron is accelerated by DC voltage
  • Focused by Focusing Electrode
  • Convert photoelectron image to visible ray again
X-ray system

1) X-ray signal is converted to visible light by scintillator

2) Visible light is converted to electric signal by Photodiode

3) Signal saved in each pixel by transistor is sent to computer with high speed

 
 
X-ray system

1) X-ray signal is directly converted to electric signal by Photoconductor

2) Signal saved in each pixel by transistor is sent to computer with high speed

 

Image Intensifier

FPD

Remark

Principle

X-ray > Input phosphor (CsI) > Amplification > Output phosphor > Visible ray > Digital Camera Integration

X-ray > Input phosphor  (CsI)

> Visible ray > Camera Integration

–

Sensor

CCD Camera Integration

Cmos Sensor

Decide difference of color sense and quality

Resolution

11 Lp/mm

8 Lp/mm

Decide image definition

Frame rate

30 ~ 48 f/s

4 ~ 8 f/s

Decide scanning speed

Distortion rate

Approx. 3%

Approx. 0%

Decide image distortion

Installation place

Large space

Small space

Decide System construction

 

Focal spot size

X-ray system
  • Focal Spot

     – The point electron colliding to Target

  • Focal Spot Size

     – Diameter of Focal Spot decides resolution. Smaller Focal spot size, better resolution.
X-ray system X-ray system