Radiographic(x-rays & gamma rays)

Presented by: Mohanad faek noori

1.1 Introduction1. This module presents information on the NDT method of radiographic inspection

or radiography.2. Radiography uses penetrating radiation that is directed towards a component. 3. The component stops some of the radiation. The amount that is stopped or

absorbed is affected by material density and thickness differences. 4. These differences in “absorption” can be recorded on film, or electronically. 5. Detection of internal defects such as porosity, voids and inclusions

Fig (1)

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1.2 Electromagnetic RadiationThe radiation used in Radiography testing is a higher energy (shorter wavelength) version of the electromagnetic waves that we see every day. Visible light is in the same family as x-rays and gamma rays.

Fig (2)

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1.3 Technology development

The essential difference between X-Rays and Gamma Rays and other electromagnetic radiations such as light, Ultra-violet rays and infrared rays from the testing and evaluation point of view is that X-Ray and Gamma Rays are able to penetrate matter which is opaque to light but have a photographic action similar to light.

Fig (3)

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1.4 Characteristics of Gamma Radiation and X-Rays :-

1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations differ only in the amount of energy they have.

2. Gamma radiation is able to travel many meters in air and many centimeters in human tissue. It readily penetrates most materials and is sometimes called "penetrating radiation”

3. Radioactive materials that emit gamma radiation and X-rays constitute both an external and internal hazard to humans.

4. Gamma radiation or X-rays frequently accompany the emission of alpha and beta radiation.

Fig (4)5

1.5 Advantages of Radiography

1. -Technique is not limited by material type or density. 2. -Can inspect assembled components. 3. -Minimum surface preparation required. 4. -Sensitive to changes in thickness, corrosion, voids, cracks, and material

density changes. 5. -Detects both surface and subsurface defects.6. -Provides a permanent record of the inspection.

1.6 Disadvantages of Radiography

7. -Many safety precautions for the use of high intensity radiation. 8. -Many hours of technician training prior to use.9. -Determining flaw depth is impossible without additional angled exposures.10. -Expensive initial equipment cost. 11. Access to both sides of sample required.12. Orientation of equipment and flaw can be critical.

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1.7 General Principles of Radiography

Top view of developed film

X-ray film

The part is placed between the radiation source and a piece of film. The part will stop some of the radiation. Thicker and more dense area will stop more of the radiation.

= more exposure

= less exposure

The film darkness (density) will vary with the amount of radiation reaching the film through the test object.

Fig (5)

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2.1 X-ray1. Electromagnetic radiations.

2. Wavelength of x rays 0.01 to 10 nanometers longer than gamma rays.

3. Can penetrate some solids and liquids, and all uncompressed gases.

4. Used for diagnostic radiology.

2.2 Radiation SourcesIndustrial radiography is often subdivided into “X-ray Radiography” or “Gamma Radiography”, depending on the source of radiation used.

Fig (6)

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2.3 Computed Radiography

Computed Radiography (CR) is a digital imaging process that uses a special imaging plate which employs storage phosphors.

Fig (7)

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Motor

A/D

Converter

A/D

Converter

Imaging Plate

Optical Scanner Photo-multiplier Tube

110010010010110110010010010110

Laser Beam

As a laser scans the imaging plate, light is emitted where X-rays stimulated the phosphor during exposure. The light is then converted to a digital value.

Fig (8)11

2.4 Parts of X-ray machine x-rays are produced by an X-ray generator

system,These systems typically include an:-

1) X-ray tube head2) high voltage generator3) control console• X-rays are produced by establishing a very

high voltage between two electrodes, called the anode and cathode.

• To prevent arcing, the anode and cathode are located inside a vacuum tube, which is protected by a metal housing.

Fig (8)Parts of X-ray machine

control

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Fig (10) X-ray Radiography

High Electrical Potential

Electrons

-+

X-ray Generator or Radioactive Source Creates Radiation

Exposure Recording Device

Radiation Penetrate the Sample

• The cathode contains a small filament much the same as in a light bulb.

• Current is passed through the filament which heats it. The heat causes electrons to be stripped off.

• The high voltage causes these “free” electrons to be pulled toward a target material (usually made of tungsten) located in the anode.

• The electrons impact against the target. This impact causes an energy exchange which causes x-rays to be created.

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Medicine: for medical analysis.

Industry: to inspect products made by various kinds of materials.

Science: to analyze the arrangement of atoms in many kinds of substances, particularly crystals.

Consumer Goods: X-rays are also used in consumer goods the manufactures treat certain kinds of plastic to check the quality of many mass produced products.

Also suitable for detecting changes in

1. Material composition 2. Thickness measurement 3. Locating defective parts or components from assembled part

2.5 Uses

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3.1 Gamma Radiography

1. Gamma-ray is often denoted by the Greek letter gamma,

2. Gamma-ray is a form of radiant energy from the atom nuclei emission of radioactive substances or electromagnetic radiation produced by radioactivity or nuclear

3. Gamma rays are produced by a radioisotope.

4. Gamma-ray wave length ranging is between 10–5 nm to 0.1 nm

5. Gamma-ray has frequencies between 1020 - 1025 Hz

3.2 The type that this inspection can detect:1. cracks2. non-uniformity of material3. density change4. weld defects3.3 Equipment :5. portable or fixed setups on industry / company requirement 6. traditional radiography requires film development facilities and equipment

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3.4 The occurrence of Gamma-ray

Gamma-ray () is resulted from the destruction of the merger process of two high-energy atomic nuclei in atomic nuclei (gamma decay) and high-energy particle interactions of sub-atomic in natural processes and man made mechanisms.

Fig (11)

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3.5 Gamma ray use :-

1. medicine :- Gamma rays used in medicine for kill carcinogens cells and prevent them from growing.

2. industry :- Gamma rays are used in industry to check the oil pipeline and discover the weak points.

3. the field of science :- Gamma rays used in the development of nuclear reactors and bombs.

3.6 Flaw Orientation :

Radiography has sensitivity limitations when detecting cracks. Gamma-rays “see” a crack as a thickness variation and the larger the variation, the easier the crack is to detect. When the path of the Gamma-rays is not parallel to a crack, the thickness variation is less and the crack may not be visible.

Fig (12)

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3.7 Question

λ = 1.10-4 nmVelocity of the wave in vacuum is 3.108 m/s. Determine the frequency of gamma-ray (λ = 1.10-4 nm)!

Known:

v = 3.108 m/s

λ = 1.10-4 nm

Asked:

f = ?

Answered:

f =vλ

f =3 x108

1 x10−4 x10−9

f =3 x1021Hz

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1919

We often hear about Islam, what is Islam ?

Learn through these sites about Islam and to all questions that revolve in your thoughts about this religion, and raise the level of your culture in learning religions enjoy the following sites to know everything about Islam :-

My first step in Islam :- ( http://www.1ststepsinislam.com/en/introduction.aspx )

Women in Islam :-( http://womeninislam.ws/en/introduction.aspx )

The key to understanding Islam :- http://www.thekeytoislam.com/

This is true :- http://www.thisistruth.org/

Learn about Islam will change your life , There is no money nor power nor any thing can change your life ,Islam will change your life and you will feel very happy.

We often hear about Islam, what is Islam ?Do you have money and everything but feel dissatisfaction in your heart is not the goal of your life?! Do you want to save you from this case?Introduction to Islam through these sites and I promise you will find great pleasure

My first step in Islam :- ( http://www.1ststepsinislam.com/en/introduction.aspx )

Women in Islam :-( http://womeninislam.ws/en/introduction.aspx )

The key to understanding Islam :- http://www.thekeytoislam.com/

This is true :- http://www.thisistruth.org/

My brother, my sister, after that follow the religion of truth and become a Muslim This site should catch a lot (the new Muslim guide) http://www.newmuslimguide.com/en/store

Learn about Islam will change your life , There is no money nor power nor any thing can change your life ,Islam will change your life and you will feel very happy.

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Contans:-

1.1 Introduction1.2 Electromagnetic Radiation1.3 Technology development1.4 Characteristics of Gamma Radiation and X-Rays1.5 Advantages of Radiography1.6 Disadvantages of Radiography1.7 General Principles of Radiography

2.1 X-ray2.2 Radiation Sources2.3 Computed Radiography2.4 Parts of X-ray machine2.5 Uses

3.1 Gamma Radiography3.2 The type that this inspection can detect3.3 Equipment 3.4 The occurrence of Gamma-ray3.5 Gamma ray use 3.6 Flaw Orientation3.7 Question

http://en.wikipedia.org/wiki/X-ray http://www.stmary.ws/highschool/physics/xray_1.htm http://science.howstuffworks.com/dictionary/physics-terms/xray-info2.htm dsu-physics.org/physics180/physics180B/Topics/electromagnetism/images_em/em_sp ectrum5.g

if http://en.wikipedia.org/wiki/Gamma_ray http://tienkartina.wordpress.com/2010/08/27/sinar-gamma/ http://minamini.wordpress.com/tag/sinar-gamma/ http://fisikasmasmk.blogspot.com/2012/02/spektrum-gelombang-elektromagnetik.html http://paling-asik.blogspot.com/2012/03/spektrum-gelombang-elektromagnetik-dan.html http://budisma.web.id/materi/sma/fisika-kelas-x/pemanfaatan-spektrum-gelombang-elektromagne

tik-dalam-kehidupan/ http://www.mediabali.net/fisika_hypermedia/spektrum_em.html http://id.shvoong.com/exact-sciences/physics/2310506-fisika/ http://makalah-artikel-online.blogspot.com/2009/04/spektrum-gelombang-elektromagnetik.html http://kliktedy.wordpress.com/2009/10/20/radioaktivitas-sinar-gamma/ http://vespaungu.wordpress.com/2012/04/25/gamma-knife-dan-pengenalannya/ http://gammaknifeindonesia.com/id/2012/04/11/gamma-knife-metode-bedah-otak-tanpa-pisau/ https://orise.orau.gov/reacts/guide/gamma.htm Book : Volume 17 nondestructive evaluation and quality control

Reference

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