3/2003 Rev 1 I.4.2 – slide 1 of 20 Part I Review of Fundamentals Module 4Sources of Radiation Session 2Cosmic Radiation Module I.4.2 IAEA Post Graduate Educational Course Radiation Protection and Safe Use of Radiation Sources

3/2003 Rev 1 I.4.2 – slide 2 of 20 Introduction  Cosmic radiation from space will be discussed  Students will learn about cosmic radiation, cosmogenic radionuclides, variance of cosmic radiation with latitude and altitude, and exposure from cosmic radiation

3/2003 Rev 1 I.4.2 – slide 3 of 20 Content  Cosmic radiation  Cosmogenic radionuclides  Radiation variance with latitude and altitude  Dose rates from cosmic radiation

3/2003 Rev 1 I.4.2 – slide 4 of 20 Overview  Cosmic radiation and its health significance will be discussed  Cosmogenic radionuclides will be listed and described

3/2003 Rev 1 I.4.2 – slide 5 of 20 Types of Cosmic Radiation  Primary cosmic radiation  Secondary cosmic radiation

3/2003 Rev 1 I.4.2 – slide 6 of 20 Primary Cosmic Radiation  Made up of extremely high energy particles (up to eV)  Composed mostly of protons or sometimes larger particles  Large percentage comes from outside solar system  Some comes from sun in form of solar flares

3/2003 Rev 1 I.4.2 – slide 7 of 20 Secondary Cosmic Radiation  Produced by interaction of primary cosmic radiation with the atmosphere  Is what we actually receive here on Earth  Lower energy radiations in the form of photons, electrons, neutrons,and muons

3/2003 Rev 1 I.4.2 – slide 8 of 20 Background Radiation Galactic radiation is a component of the background radiation on earth.

3/2003 Rev 1 I.4.2 – slide 9 of 20 Background Radiation Cosmic radiation contributes to the background radiation on earth. The earth’s atmosphere provides shielding from most of the cosmic radiation.

3/2003 Rev 1 I.4.2 – slide 10 of 20 Background Radiation The dose from cosmic radiation is reduced at lower altitude due to the additional shielding by the earth’s atmosphere.

3/2003 Rev 1 I.4.2 – slide 11 of 20 Cosmogenic Radionuclides NuclideHalf-lifeSource Natural Activity 14 C 5730 yr Cosmic-ray interactions, 14 N(n,p) 14 C 0.22 Bq/g 3H3H3H3H 12.3 yr Cosmic-rayInteractions with N and O 1.2 x Bq/kg 7 Be 53.3 days Cosmic-rayInteractions with N and O 0.01 Bq/kg

3/2003 Rev 1 I.4.2 – slide 12 of 20 Cosmic Ray Doses Subsonic Flight at 11 km Route Flight Duration (hrs) Dose per round trip (  Gy) Los Angeles – Paris Chicago – Paris New York - Paris New York - London Los Angeles - New York Sydney - Acapulco

3/2003 Rev 1 I.4.2 – slide 13 of 20 Cosmic Ray Doses Supersonic Flight at 19 km Route Flight Duration (hrs) Dose per round trip (  Gy) Los Angeles – Paris Chicago – Paris New York – Paris New York – London Los Angeles - New York Sydney - Acapulco 6.221

3/2003 Rev 1 I.4.2 – slide 14 of 20 Typical Cosmic Ray Dose Rates  4 x Sv/hr at ground level in Northeastern US  2 x Sv/hr at 4.6 km altitude  3 x Sv/hr at 16.8 km altitude

3/2003 Rev 1 I.4.2 – slide 15 of 20 Natural Radiation Exposure Around the World

3/2003 Rev 1 I.4.2 – slide 16 of 20 Cosmic Dose Rate Map of Switzerland

3/2003 Rev 1 I.4.2 – slide 17 of 20 Effective Dose Equivalent to a Member of the Population of the United States Source Average Annual Effective Dose Equivalent  Sv mrem  Sv mrem Inhaled (radon and decay products) Other Internbally Deposited Radionuclides Terrestrial Radiation Cosmic Radiation 2727 Cosmogenic Radioactivity 101 Rounded Total from Natural Sources Rounded Total from Artificial Sources Total

3/2003 Rev 1 I.4.2 – slide 18 of 20 Sources of Radiation Exposure In the United States

3/2003 Rev 1 I.4.2 – slide 19 of 20 Summary  Cosmic radiation was discussed  Cosmogenic radiouclides were listed and discussed  Radiation variance with latitude and altitude was described  Dose rates from cosmic radiation were discussed.

3/2003 Rev 1 I.4.2 – slide 20 of 20 Where to Get More Information  Cember, H., Introduction to Health Physics, 3 rd Edition, McGraw-Hill, New York (2000)  Firestone, R.B., Baglin, C.M., Frank-Chu, S.Y., Eds., Table of Isotopes (8 th Edition, 1999 update), Wiley, New York (1999)  International Atomic Energy Agency, The Safe Use of Radiation Sources, Training Course Series No. 6, IAEA, Vienna (1995)