Types and Sources of Ionizing Radiation - Ionizing radiation consists of subatomic particles or electromagnetic waves. - Gamma rays, X-rays, and higher energy ultraviolet rays are ionizing radiation. - Lower energy ultraviolet, visible light, infrared, microwaves, and radio waves are non-ionizing radiation. - Typical ionizing subatomic particles include alpha particles, beta particles, and neutrons. - Secondary cosmic particles produced after cosmic rays interact with Earth's atmosphere include muons, mesons, and positrons. - Cosmic rays and decay of radioactive isotopes are primary sources of natural ionizing radiation. - Artificial sources include X-ray tubes, particle accelerators, and nuclear fission. - Radioisotopes produced by cosmic rays on Earth contribute to background radiation. - Ionizing radiation is used in fields like medicine, nuclear power, research, and industrial manufacturing. - Proper measures must be taken to prevent excessive exposure to ionizing radiation.

Detection and Measurement of Ionizing Radiation - Ionizing radiation is not immediately detectable by human senses. - Instruments like Geiger counters are used to detect and measure ionizing radiation. - High energy particles can produce visible effects on organic and inorganic matter. - Ionizing radiation can cause acute radiation syndrome in humans. - Visible effects of ionizing radiation include water lighting in Cherenkov radiation.

Directly Ionizing Radiation - Charged particles with sufficient kinetic energy can ionize atoms directly. - Examples of directly ionizing radiation include alpha particles, electrons, muons, and protons. - Relativistic speeds of particles determine their ionizing capability. - Alpha particles and energetic electrons were among the first types of directly ionizing radiation discovered. - Natural cosmic rays primarily consist of relativistic protons and heavier atomic nuclei. - Alpha particles are helium nuclei consisting of two protons and two neutrons. - They are produced in the process of alpha decay. - Alpha particles have low penetration power and can be absorbed by air or human skin. - Ternary fission produces more energetic alpha particles that penetrate farther in air. - Alpha particles are strongly ionizing and pose shielding problems in space.

Indirectly Ionizing Radiation - Indirectly ionizing radiation is electrically neutral and does not strongly interact with matter. - The bulk of ionization effects from indirectly ionizing radiation are due to secondary ionization. - Photons can ionize atoms indirectly through the photoelectric effect and the Compton effect. - The ejection of an electron from an atom at relativistic speeds turns it into a secondary beta particle that can ionize other atoms. - Radiated photons are called gamma rays if produced by a nuclear reaction or radioactive decay within the nucleus, and x-rays if produced outside the nucleus. - Photons are electrically neutral but can ionize atoms indirectly through the photoelectric effect and the Compton effect. - Gamma rays are produced by nuclear reactions, subatomic particle decay, or radioactive decay within the nucleus. - X-rays are produced outside the nucleus and typically have lower energy than gamma rays. - The boundary between X-rays and gamma rays has historically been defined by energy thresholds, but there is overlap between the two. - In astronomy, gamma rays and X-rays are functionally identical, differing only in the origin of the radiation.

Effects of Ionizing Radiation - Ionizing radiation can cause nuclear transmutation and induced radioactivity. - Neutron activation, alpha absorption, and photodisintegration are the mechanisms behind nuclear effects. - Transmutations can change macroscopic properties and cause targets to become radioactive. - Ionization of molecules can lead to radiolysis and formation of highly reactive free radicals. - Ionizing radiation can accelerate chemical reactions such as polymerization and corrosion. - Ionizing radiation can cause radiolysis, breaking chemical bonds. - Highly reactive free radicals formed by ionization can react with neighboring materials. - Ionizing radiation can accelerate existing chemical reactions. - Optical materials can deteriorate under the effect of ionizing radiation. - High-intensity ionizing radiation in air can produce a visible ionised air glow. - Ionization of materials temporarily increases their conductivity. - Damaging current levels can be permitted, posing a hazard in semiconductor microelectronics. - Devices intended for high radiation environments may be made radiation hard. - Proton radiation in space can cause single-event upsets in digital circuits. - Gas-filled radiation detectors exploit the electrical effects of ionizing radiation. - Adverse health effects of exposure to ionizing radiation can be grouped into deterministic and stochastic effects. - Deterministic effects are harmful tissue reactions due to high doses from radiation burns. - Stochastic effects include cancer development and heritable effects. - The most common impact is the stochastic induction of cancer with a latent period of years or decades. - The Linear no-threshold model (LNT) is the most widely accepted model for predicting the level of risk. - Radiation and dose quantities can be measured using SI and non-SI units. - Background radiation levels vary across different areas, ranging from as low as 1.5mSv/a to over 100mSv/a. - The highest recorded natural radiation level on Earth's surface is 90µGy/h (0.8Gy/a) on a Brazilian black beach. - Ramsar, an inhabited area, has the highest background radiation due to naturally radioactive limestone used in buildings. - Some residents in Ramsar receive an average radiation dose of 10mGy per year, ten times more than the recommended limit. - Despite the high levels, there is no compelling evidence of increased health risks for the residents. - Cosmic radiation consists of relativistic particles from outside our solar system. - It includes positively charged nuclei (ions) ranging from 1 amu protons to 26 amu iron nuclei. - The energy of cosmic radiation can exceed what humans can create in particle accelerators. - The dose from cosmic radiation is largely from muons, neutrons, and electrons. - Airline flight crew workers receive more cosmic ray dose on average than any other worker. - Most materials