Ionizing Radiation!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

E= MC^2

Albert Einstein discovered that energy can be converted to mass and vice versa using what relationship?

Alpha and beta particles

All forms of radiation express the energy they carry as electron volts, which helps determine whether it is ionizing or non-ionizing. ___________ and ______________________ are all considered to carry enough energy to be ionizing. Where photons can be considered either non-ionizing or ionizing depends on where they fall within the spectrum.

neutron rich

Alpha decay occurs in very heavy elements such as uranium, thorium, and radium. The nuclei of these atoms are very ___________________________ , which makes emission of the alpha particle possible.

electron clouds

Alpha radiation transfers energy to the _______________________________ in its path and can either excite or ionize an atom.

neutrons to protons

An atom is either stable or unstable. The ratio of __________________ to _________________ within the nucleus determines whether an atom is stable

cobalt-59

An atom of cobalt that has 27 protons and 32 neutrons is called _________________.

decay chain

An unstable atom does not always decay directly to a stable state immediately; it may undergo a series of radioactive decays called a ____________________.

bremsstrahlung

As a relatively fast moving beta particle or electron nears the nucleus, the attractive force alters its trajectory and slows it down. This interaction results in a loss of kinetic energy which is converted to x-rays. This energy is released in the form of a____________________________ x-ray. The amount of energy lost, and thus the energy of the xray, depends upon how closely the electron passes to the nucleus.

decay

Atoms that remain unstable following a transformation will continue to ______________ until a stable atom is formed.

local commanders

BE advises ________________________________ during contingency operations regarding the potential for personnel injuries from radiation emissions.

unit commanders and shop supervisors

BE roles in radiation safety can be summed up as assisting ______________________________ and ____________________________________ in identifying and controlling radiation hazards and developing an effective safety and awareness training program.

low ionization

Beta particles are much lighter and more penetrating than alpha particles; however, they have a __________________________ potential, meaning that they are not as energetic as alpha particles.

metal or plastic

Beta particles will travel up to several meters in air and are stopped by thin layers of ___________________ or ________________.

isotopes

Cobalt-59 and cobalt-60 are ______________ of cobalt.

-RDDs -Radiological dispersal device

Commonly referred to as ___________, or dirty bombs, a _______________________________________ is simply radioactive material, such as Cs-137, mixed with an explosive, such as TNT. The intention is to spread the radioactive material and contaminate an area.

protons and neutrons

Each element has different isotopes which carry different characteristics. These isotopes are determined by the combined number of _________________ and _______________ in the nucleus.

neutrons

Each proton has a positive charge. The number of protons in an atom of a particular element is always the same, but the number of ______________ may vary.

electron cloud

Electrons circle in the ______________________ outside the positive nucleus. Electrons have a negative charge. The ______________________ contains seven major electron shells each containing different levels of energy.

radioactive

Every ______________________ nucleus will eventually change its neutron/proton through one of the forms of radiation.

1.5:1

For heavy elements, the n:p ratio for stability increases to approximately ________.

1:1

For light elements, meaning those on the lower end of the periodic table, the appropriate ratio is about ______.

alpha

Further, _____________ particles are very heavy and very energetic compared to other types of radiation. These characteristics cause them to move relatively slowly and interact strongly with the atoms of any material they pass through, including air, producing dense ionization along their path.

ionizing

Gamma rays are the most penetrating but the least ____________________ type of radiation.

neutrons

If there are too many or too few _______________ for a given number of protons, the resulting nucleus contains too much energy and is unstable. Stated very simply, an atom wants to be stable.

as low as reasonably achievable (ALARA)

In general, BE is focused on reviewing control measures during surveys and providing ______________________________________________ training.

binding energy

In its simplest terms, __________________ is the energy that holds a nucleus together, and as such, is also the amount of energy required to break it apart.

-Nuclear Regulatory Commission (NRC) -Radioisotope Committee (RIC) -Installation Radiation Safety Officer (IRSO) -Permit RSO

In your role as a member of the BE flight, you will interact with the following agencies:

energy

Ionizing photons interact with material through the photoelectric effect, Compton scattering, and pair production. A photon's __________________ is the primary factor in determining which of these happens.

particles and rays

Ionizing radiation includes ______________ and ______________ given off by radioactive material, stars, and high-voltage equipment. These radiation ______________ and _____________ carry enough energy to strip electrons from atoms and molecules that they hit or pass near. This process is called ionization.

heat and light

Ionizing radiation, like __________ and _________, is a form of energy. Most of it occurs naturally, and some is produced by human activities.

-protons -neutrons

Isotopes, of the same element, have the same number of ___________ but differ in the number of ___________.

photons

Like beta radiation, __________________ have low LET. Radiation that has no electrical charge (such as gamma rays and x-rays) cannot interact with electrical fields created by electrons and protons. They must collide with these particles to interact.

photons

Matter is made up of mostly empty space, ______________ are able to move freely through matter, with small probability of interacting. In contrast to charged particle interactions with matter, uncharged radiation does not continuously lose energy by constantly interacting with the absorbing matter.

neutrons

More and more ______________ are needed per proton to buffer the repulsive forces between the protons.

atomic mass units (AMU)

Neutron and proton weight is typically expressed as _________________________, 1 ______________________ is equal to the weight of a stable carbon atom at rest divided by twelve.

neutralize

Neutrons ________________ the repelling action of the protons and help hold the protons together in the nucleus.

fission and neutron activation

Neutrons are typically found in nuclear facilities where _______________ (the splitting of an atom) and _______________________________ are of interest because there are no pure neutron emitters. Strong neutrons are emitted during fission and are a primary hazard during the blast phase of a nuclear detonation.

nuclear activation

Neutrons can interact with target nuclei by being captured by the nucleus, which changes the isotope of that nucleus, creating an unstable, or radioactive, atom. This process is called _____________________________.

positrons

Positively charged beta particles, known as __________________, have no negative impact on particles with which they interact.

solid, liquid, or gas

Radiation will interact with matter at the atomic level. It will lose kinetic energy to any __________, __________, or ___________ through which it passes.

Industrial Use Sources

Radioactive material is used extensively in equipment calibration, research, smoke detectors, chemical detectors, and even in aircraft dials and wrist watches. Some of the common permitted items on an Air Force installation are chemical detectors used by CE Emergency Management containing Co-60 and calibration sources such as Sr-90 used by PMEL. What type of source is this?

-medical -industrial

Radioactive sources are used extensively both in Air Force operations and in the civilian sector. These sources are typically classified as either _______________ use sources or __________________ use sources

gamma ray

Since a ___________________________________ is pure energy, once it loses all its energy, it no longer exists.

radiation safety program

The IRSO establishes and manages the base ____________________________________ through training, surveillance, and control recommendations.

thermoluminescent dosimetry program

The IRSO manages the installation __________________________________________________ to track all workplace exposures to ionizing radiation.

(AFI) 48-148

The NRC establishes enforceable action limits for ionizing radiation, Air Force Instruction _____________________, Ionizing Radiation Protection, is based on these standards and specifies the requirements for protection of USAF personnel and their dependents from ionizing radiation.

nuclear materials

The NRC regulates the civilian use of _____________________________________ to ensure adequate protection of public health and safety, to promote the common defense and security, and to protect the environment.

AFI 48-148

The PRSO establishes and manages the organization or unit radiation safety program, _______________________, to include the following activities: -Training -Routine monitoring -Surveillance activities -Exposure control activities -Review of procedures and practices -Facility design review and classification

photoelectric effect

The _______________________________ occurs when a low energy photon strikes an atom, where the total energy of the gamma is expended in ejecting an electron from orbit. The result is ionization of the atom and expulsion of a high energy electron. The remaining electrons must drop to fill in the inner shell.

workplace supervisor

The ________________________________ is responsible for informing BE of new processes or changes to processes involving any form of radiation.

Nuclear Regulatory Commission (NRC)

The _____________________________________ is an independent agency established by the Energy Reorganization Act of 1974.

INSTALLATION RADIATION SAFETY OFFICER (IRSO)

The _____________________________________ provides consultant support to the installation commander on radiation protection issues and keeps installation commanders informed about radiation health and safety issues and effectiveness of measures to control radiation hazards.

Permit Radiation Safety Officer (PRSO)

The _______________________________________ provides consultant support to organization or unit commanders on radiation protection issues. They keep organization and unit commanders and the IRSO informed about radiation health and safety issues and effectiveness of measures to control ionizing radiation hazards.

Nuclear Regulatory Commission (NRC)

The _______________________________________ regulates commercial nuclear power plants and other uses of nuclear materials, such as in nuclear medicine, through licensing, inspection, and enforcement of its requirements.

Radiation Safety Program

The _________________________________________ identifies and establishes the methods used to protect workers and the public from all forms of radiation.

Radioisotope Committee (RIC)

The _________________________________________, composed of members throughout the Air Force, is responsible for providing regulatory oversight for the use of radioactive materials by Air Force organizations (except weapons-related materials falling under Section 91(b) of the atomic energy act).

law of conservation of energy

The __________________________________________ can be stated simply: "Energy cannot be created or destroyed, it can only be changed from one form to another."

Radioisotope Committee (RIC)

The ___________________________________________ approves controls for acquiring, receiving, storing, distributing, using, transferring, and disposing of radioactive material to ensure compliance with the Air Force Master Materials License, Nuclear Regulatory Commission policy and guidance, other applicable regulatory requirements, and DOD and Air Force directives and instructions.

linear energy transfer (LET)

The amount of energy that the radiation transfers per unit of path length is called its _____________________________________.

identify, evaluate, and control

The approach to radiation hazard management is very similar to the methodology used for other types of occupational and environmental health (OEH) hazards such as noise or chemical--________________, ________________, and _______________ potential hazards.

element

The appropriate n:p ratio required for stability depends upon the ________________.

-parent -progeny -daughter

The first radionuclide in the chain is called the __________________ radionuclide, and the subsequent products of the transformation are called __________________ or _________________ products.

electron volt (eV)

Though the system international (SI) unit used to express energy is a joule, the most common expression encountered in physics at the atomic level is the ______________. One _____________ is equal to approximately 1.6 x 10-19 joules.

Medical Use Sources

To diagnose cancer, a radioactive dye, such as fluorine 18, can be used to provide contrast for PET scans. Radioactive isotopes are also used for therapeutic purposes. Iodine-131 is one such isotope that is used to treat thyroid cancer. What type of source is this?

laser safety officer (ILSO)

You may also encounter an installation ________________________________________, whose responsibilities are similar to the IRSO, but for laser safety hazards.

Neutrons and protons

_____________ and ____________ add to the weight of the atom.

Alpha

_______________ radiaition has high LET. The two protons in the particle give an alpha particle a positive charge of two.

Photons

________________ may pass through matter without hitting anything, or it may hit an atom and transfer all or part of its energy. This normally ionizes the atom. This electron then uses the energy it received from the gamma ray to ionize other atoms by knocking electrons out of them as well

High LET

_________________ forms of radiation, such as alpha, ionize water into H and OH radicals over a very short track. For example, two ionization events occur in a single cell so as to form a pair of adjacent OH radicals that recombine to form peroxide, H2O2, which can produce oxidative damage in the cell.

Neutrons

__________________ are high-speed nuclear particles that have an exceptional ability to penetrate other materials.

electrons

__________________ in an excited state move to a higher energy state, or shell, where ionized _________________ are removed from the atom completely.

Workers

___________________ are obligated to follow safety procedures as outlined in AF standards, equipment technical orders (TOs), manuals, and unit operating instructions (OIs), and they must practice safe working conditions. It is the ________________ responsibility to comply with warning signs, to check that safety devices are working correctly, and to promptly report any suspected overexposure and unsafe work conditions to his/her supervisor.

Alpha decay

___________________ is a radioactive process in which a particle with two neutrons and two protons is ejected from the nucleus of a radioactive atom. The two protons and two neutrons make an alpha particle identical to a helium atom, but without the electrons.

Low LET

____________________ forms of radiation, such as like x-rays or gamma rays, also ionize water molecules, but over a much longer track. For example, two ionization events now occur in separate cells, such that adjacent radicals are of the opposite type: the H and OH radicals reunite and reform H2O.

Radioactivity

_____________________ is the spontaneous transformation of an unstable atom that often results in the emission of radiation. This process is referred to as a transformation or decay.

Ionization potential

_______________________ is the amount of energy required to ionize (remove) the least tightly bound electron in an atom of that element. Atoms of different elements have varying ionization potentials, and as such, require different amounts of energy to remove their respective electrons.

Beta decay

_______________________ is the emission of electron-like particles from the nucleus of an atom. These particles may have a positive or negative charge. Beta particles are made in one of two ways—conversion of a proton to a neutron or conversion of a neutron to a proton— depending on the radioactive material that produces them.

binding energy

________________________ is not something encountered often, but it is a key aspect to nuclear fusion and nuclear fission, both of which you will encounter in the nuclear enterprise section of this block.

Pair production

________________________ occurs as a high energy photon enters the area around the nucleus of an atom; the energy is converted into the mass of two electrons, with the remaining energy being imparted as kinetic energy (Fig. 14). These new particles have opposing charges; one positive and one negative, and as such exit the atom at separate angles.

Alpha particles

___________________________ ionize atoms very strongly; because of this, they are the least penetrating of radiation types. In fact, the dead, outer layer of skin is sufficiently thick enough to stop almost all ___________________________. However, if ____________________________ are inhaled, ingested or injected the energy will be dissipated in living tissue.

Beta particles

___________________________, which are energetic electrons, are classified as low LET radiation. Even though they interact with matter in a manner similar to alpha particles, their smaller +1 or -1 charge and smaller mass result in a greater distance between ionizing collisions— thus, a lower rate of energy transfer.

Gamma rays

____________________________ are bundles of energy that have no charge or mass. This allows them to travel very long distances through air, body tissue, and other materials.

RAM permits

_____________________________ are required to list all RAM used by an organization. Each source on the permit will be listed with its using organization, isotope, activity, serial number, storage location, and survey requirements. Current copies of RAM permits are maintained by the PRSO, IRSO, and in many instances, Bioenvironmental Engineering.

Neutron radiation

_____________________________ is unique in that, though it is ionizing radiation, it is considered to be indirectly ionizing. Because neutrons have no charge, they do not affect the electron cloud. Neutrons interact only with target nuclei through elastic scattering, inelastic scattering, and neutron capture.

Gamma radiation

_____________________________, usually referred to as gamma rays or photons, is not a particle like alpha and beta; instead, it is a bundle of electromagnetic energy similar to EMF and visible light.

Alpha particles

_______________________________ have a good deal of kinetic energy or energy of motion. Despite this, they do not travel very far, only centimeters.

Bioenvironmental Engineers

_______________________________ is the central focal point and expert on radiation hazards and biological effects with support from the USAF School of Aerospace Medicine (USAFSAM) and the Air Force Research Laboratory (AFRL). Generally speaking, each _________________________________ flight establishes a radiation safety program for each type of radiation (EMFR, IR, laser, etc.) that is present on the base.

Elastic scattering

_______________________________ occurs when a neutron collides with a nucleus, transferring kinetic energy to the target atom which results in a slower neutron and a highly energized nucleus, which goes on to become ion pairs. After several of these interactions, the neutron is slow enough to be absorbed though inelastic scattering.

Inelastic scattering

_________________________________ occurs when a neutron is absorbed or captured by the target nucleus. The nucleus then emits a lower kinetic energy neutron and a gamma photon. The gamma photon is an example of indirect ionization, where the neutron did not ionize an atom but did cause a reaction that created a form of ionizing radiation.

Neutron capture

____________________________________ is possible once the neutron has lost sufficient kinetic energy through elastic and inelastic scattering. The once stable target nucleus now carries an extra neutron which makes it unstable—radioactive. The example given in the last objective of stable Co59 absorbing a neutron and becoming the radioactive isotope Co60 is an example of neutron capture. If the resulting isotope is unstable, it will give off extra energy by converting a neutron to a proton, producing a negatively charged beta particle and a gamma photon.

Compton scattering

____________________________________ occurs when both the photon, and the electron it interacts with, are scattered in different directions. The gamma interacts with an orbital or free electron; however, in this case, the photon loses only a fraction of its energy. Some of the photon's energy is transferred to the electron, ionizing it; the rest is carried away by the scattered photon. The photon is released in a different direction, much like a pool ball.

neutron activation

Of the types of ionizing radiation discussed, neutrons are the only one that can make objects radioactive. This process, called ____________________________, occurs in nuclear power plants and during nuclear explosions.

protons

On the periodic table of elements, the number of ________________ in an atom may be expressed as the Z number, or the atomic number.

bioenvironmental engineer

The installation IRSO, in most instances, is the base ____________________________________ who has had additional training as a radiation safety officer.

element

The number of protons in an atom's center, or nucleus, determines the _______________.

Radioisotope Committee

The only Air Force organization that will communicate with the NRC is the ___________________________________.

Radioactive Material (RAM)

The organization RSO also provides assistance to commanders in developing organization-specific radiation safety operating instructions and radiation safety manuals and also conducts other requirements as specified by regulation or USAF ______________________________________ (RAM) permits.

workplace supervisor

The role of the ____________________________________ is to ensure workers follow all safety procedures, prepare the radiation frequency report, and conduct safety awareness training for all personnel that may have radiation exposure.

energy

When dealing with atomic structure, radiation, and its interaction with matter, it is important to understand the types of ______________ that are in play.

ionizing radiation

Whenever _________________________ strikes anything—wood, iron, a human body, or anything—it can have effects on matter, including living things.