AAE552-Session19

AAE552-Session19 - AAE 552 Spring 2009 A. F. Grandt AAE...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
AAE 552 Spring 2009 – A. F. Grandt 1 1 AAE 552: Nondestructive Evaluation of Structures and Materials A. F. Grandt, Jr. Professor of Aeronautics and Astronautics Purdue University W. Lafayette, IN 47907 Session 19 – 25 February 2009 2 Contact Information Alten F. (Skip) Grandt, Jr. Email: aae552@ecn.purdue.edu Telephone: Office: 765-494-5141 Home: 765-463-4276 FAX: 765-494-0307 Course webpage accessed at: http://www.itap.purdue.edu/tlt/blackboard 3 AAE 552 Session 19 25 February 2009 Last Time: Start radiography Today: Continue radiography Neutron Radiography Image Formation Computed Tomography 4 Chapter 11: Radiography Use penetrating power of x-rays or gamma rays to locate internal anomalies 5 Chapter 11: Radiography Topics Overview Absorption/Scatter Radiation sources Image formation Image quality Examples Computed Tomography Safety issues Summary 6 Assignment Please read Textbook : Chapter 11 Webpage powerpoint references “Radiographic Testing” – collaboration for NDT education Paper #1 – Due Session 21 (2 March 2009) Exam #1 – Session 29 (Friday, 27 March 2009)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
AAE 552 Spring 2009 – A. F. Grandt 2 Absorption and Scatter 7 8 Radiation Absorption Differential absorption of radiation by different materials is key to NDE I o = intensity on surface I x = intensity distance x from surface μ = coefficient of linear absorption (1/length) = function of material, energy level source I x I o x object I x = I o e - μ x (Eq. 11.3) 9 Linear Absorption Coefficients for Aluminum, Iron and Lead (Fig. 11.3) Note optimum energy for minimum λ λλ and max penetration X-ray Energy (MeV) Total linear absorption coefficient (cm -1 ) Lead Iron Aluminum I x = I o e - μ x I x I o x 10 Absorption/Scattering Mechanisms Several mechanisms for absorption and or scattering of radiation energy that passes through object Depend on energy of radiation Raleigh Scattering (E < 0.1 MeV) Photoelectric Effect (E < 0.5 MeV) Compton Scattering (0.1 MeV < E < 3 MeV) Pair Production (E > 1.02 MeV) 11 Components of Absorption Coefficient in Iron (Fig. 11.4) Note optimum energy for minimum μ and max absorption X-ray Energy (MeV) Rayleigh Photoelectric Pair production Compton Total I x = I o e - μ x Radiation sources 12
Background image of page 2
AAE 552 Spring 2009 – A. F. Grandt 3 13 Sources of Radiation (Section 11.4) X-rays X-ray tubes (~ 450 kV max) High-energy (E > 1 MeV) Tuned transformers (1 –2 MeV) Van de Graaf Generators (1 – 8 MeV) Betatrons (1-30 MeV) Linear electron Accelerators (1 – 25 MeV) Gamma rays (~0.06 – 1.8 MeV) Neutrons Radiation Sources Two of the most commonly used sources of radiation in industrial radiography are x-ray generators and gamma ray sources. Industrial radiography is often subdivided into “X-ray Radiography” or “Gamma Radiography”, depending on the source of radiation used. 15
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/04/2010 for the course AAE 552 taught by Professor Longuski during the Spring '10 term at IUPUI.

Page1 / 13

AAE552-Session19 - AAE 552 Spring 2009 A. F. Grandt AAE...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online