Terrestrial Radiation Effects in ULSI Devices and Electronic Systems

Chapter 2Terrestrial Radiation Fields

2.1 General Sources of Radiation

Figure 2.1 depicts two simplified mechanisms by which photons and/or secondary particles are produced.

Figure 2.1 Sources of terrestrial radiation: (a) nuclear reactions (photonuclear reaction, neutron capture, fission, fusion and spallation) and (b) radioactive decay

When a high-energy particle penetrates into a nucleus, various nuclear reactions take place with to the end result of decomposing the nucleus into fragments as shown in Figure 2.1a. The nuclear reactions are likely to be: neutron capture [1], fission [2], fusion [3] and spallation reaction [4]. As a result of the reactions, energetic photons, electrons, neutrons, protons, muons, pions and heavier particles are released with a residual nucleus. Even high-energy photons and electrons can produce neutrons, protons, deuteriums, tritiums and alpha particles through photonuclear reaction [5]. When these particles are charged particles, they are known as secondary ions. Photons (gamma rays), electrons (beta-rays) and helium ions (alpha-rays) are emitted through radioactive decay of unstable radioisotopes as shown in Figure 2.1b.

2.2 Backgrounds for Selection of Terrestrial High-Energy Particles

As shown in Chapter 1, most terrestrial high-energy particles are studied in this book because those particles listed in Table 2.1 have a charge or at ...