SAVEinc Glossary of Terms and Acronyms


Glossary of Terms

Absorption The process by which the number of particles or photons entering a body of matter is reduced by interaction of the particles or radiation with the matter, the reduction of the energy of a particle while traversing a body of matter.
Accelerator A device for increasing the velocity and energy of charged elementary particles through application of electrical and/or magnetic forces.
Alpha Particle A doubly ionized helium atom consisting of two protons and two neutrons.
Angstrom A unit of length equal to 1E-8 centimeters.
Annihilation Radiation A positron-negatron interaction in which the rest masses of both particles are ultimately given up as electro-magnetic radiation.
Atom The smallest particle of an element which can enter into a chemical combination.
Atomic Number The number (Z) of protons within the atomic nucleus. The electrical charge of these protons determines the number and arrangement of the outer electrons of the atom and, thereby, the chemical and physical properties of the element.
Atomic Weight Atomic weight is .the relative weight of the atom on the basis of oxygen as 16. For a pure isotope, the atomic weight rounded off to the nearest integer gives the total number of nucleons (neutrons and protons) making up the atomic nucleus.
Barn A unit area used in expressing the interaction cross-sections of atoms, nuclei, electrons, and other particles One barn is equal to 1E-24 square centimeters
Beta Particle An elementary 'particle emitted from the nucleus during radioactive decay, with a single electrical charge and a mass equal to 1/1837 that of a proton. A negatively charged beta particle is identical to an electron.
Binding Energy The binding energy of a nucleus is the minimum energy required to disassociate it into its component neutrons and protons. Neutron and proton binding energies are those required to remove a neutron or a proton, respectively, from a nucleus. Electron binding energy is that energy required to remove an electron from an atom or a molecule.
Bipolar Transistor A transistor that uses both positive and negative charge carriers.
Blackbody A perfect emitter (radiator) of electromagnetic radiation having a characteristic energy which is the sole determinant of its radiated energy spectrum.
Bremsstrahlung Electromagnetic radiation emitted (as photons) when a fast-moving charged particle (usually an electron) loses energy upon being accelerated and deflected by the electric field surrounding a positively charged atomic nucleus. X-rays produced in x-ray machines are Bremsstrahlung.
Capture A process in which an atomic or nuclear system acquires an additional particle; for example, the capture of electrons by positive ions, or capture of electrons or neutrons by nuclei.
Charge Transfer The movement of charge within a material or from one 'material to another due to the interaction of high energy nuclear radiation with the material.
Collision A close approach of two or more particles, photons, atoms, or nuclei, during which such quantities as energy, momentum, and charge may be exchanged.
Compton Effect Elastic scattering of photons by electrons resulting in a decrease in energy of photons.
Cross Section A measure of the probability of a particular process.
Curie Unit of measuring radioactivity. One curie is equal to 3.7E11 disintegrations per second.
Decay Diminution of the activity of a radioactive substance due to nuclear emission of alpha or beta particles, gamma rays, or positrons.
Dose The radiation energy absorbed-per unit mass of a material.
Dose Rate The dose absorbed per unit time.
Dosimeter device that measures radiation dose.
Electromagnetic Radiation Radiation consisting of associated and interacting electric and magnetic waves that travel at the speed of light; e.g., light, radio waves, gamma rays, and x-rays.
Electron Volt The amount of kinetic energy gained by an electron when it is accelerated through an electric potential difference of 1 volt.
Epitaxial Refers to the formation of single-crystalline material upon a single-crystalline substrate by chemical reduction from the vapor phase. The grown material assumes the same crystal orientation as the substrate.
Eutectic A mixture of two or more substances which has the lowest melting point.
Fluorescence Radiation emitted as a result of absorbing radiation energy from another source.
fluence The number of particles or photons or the amount of energy that enters an imaginary sphere of unit cross-sectional area.
Flux The flow of photons, particles, or energy per unit time through an imaginary sphere of unit cross-sectional area.
Gamma Rays Electromagnetic radiation released during a nuclear transition.
Half-Life The time in which half the atoms of a particular radioactive substance disintegrate to another nuclear form.
Injection Current The current flowing in the load of a cable exposed to photon radiation. Injection currents result from the motion of charge between the shield and wires of the cable.
Intensity Energy, particle, or photon fluence.
Ionization The process of adding one or more electrons to, or removing one or more electrons from, atoms or molecules.
Ionizing Radiation Any radiation displacing electrons from atoms or molecules.
Irradiation Exposure to radiation.
Latchup Regenerative device action in transistors or circuits in which an undesirable stable condition is obtained.
Linear Accelerator A long straight tube in which charged particles gain in energy by the action of oscillating electromagnetic fields.
Long Pulse The ionizing dose resulting from neutron irradiation. Long is a relative term indicating that the flight time spreads the neutron pulse relative to the prompt gamma pulse.
Neutron An uncharged elementary particle with a mass slightly greater than that of the proton and found in the nucleus of every atom heavier than hydrogen.
Permanent Effects Changes in material properties that persist for a long time compared with the normal response time of the system of which the material is a part.
Photocurrent A flow of excess charge carriers generated by ionizing radiation.
Photoelectric Effect A photon is absorbed in an interaction with an electron causing the struck electron to be ejected from the atom.
Photon The carrier of a quantum of electromagnetic energy.
Planckian Spectrum Blackbody energy spectrum according to Planck's radiation law.
Prompt Pulse The initial high intensity, short duration ionizing dose associated with the detonation of a nuclear weapon. This is also known as the short pulse.
Replacement Current The photoejection from and transfer of charge in a system creates a charge imbalance. The charge redistributes itself in a fashion dictated by the electrical characteristics of the system's structure. The resulting current is called a replacement current.
Roentgen A unit of ionization equivalent to dose of 87.7 ergs per gram in air.
Secondary Electron An electron emitted as a result of bombardment of a material with radiation.
Shielding The technique of enclosing an object within a container specifically designed to attenuate or otherwise exclude nuclear or electromagnetic radiation.
Spall Dynamic fracture of a material resulting from a very short duration stress pulse.
Stopping Power The measure of the effect of a substance upon the kinetic energy of a charged particle passing through it.
Total Dose The total ionizing dose received by the device from the various radiation environments.
Transient Effects Change in material properties that persist for a time shorter than or comparable to, the normal response time of the system of which the material is a part,
X-ray A penetrating form of electromagnetic radiation emitted either when the inner orbital electrons of an excited atom return to their normal state or when a charged particle is accelerated or decelerated.


Glossary of Acronyms

ASAT Anti-Satellite
AVCS Altitude and Velocity Control Subsystem
CCB Configuration Control Board
CIT Current Injection Test
CMOS PMOS and NMOS utilized as a complementary pair
D Total dose in rad(Si)
DCD Dual Command Decoder
DEMP Dispersed Electromagnetic Pulse
DIIC Dielectric Isolated Integrated Circuit
DL Design Limits
DT Design Tolerance
ECEMP Electron Caused Electromagnetic Pulse
EMP Electromagnetic Pulse
EPS Electrical Power System
EVDP Elemental Volume Dose Program
FBR Fast Burst Reactor
FDC Final Design Complete
FDC Final Design Complete
FDV Functional Design Verification
FET Field Effect Transistor
FXR Flash X-ray
G Dose rate in rad(Si)/s
HA Hardness Assurance
HAP Hardness Assurance Program
HAPP Hardness Assurance Program Plan
HAWG Hardness Assurance Working Group
HCC Hardness Critical Category
HCI Hardness Critical Item
HCP Hardness Critical Process/Procedure
HDM Hardness Design Margin
IC Integrated Circuit
IEMP Internal Electromagnetic Pulse
IMP Integrated Master Plan
IMS Integrated Master Schedule
IPT Integrated Product Team
JFET Junction Field Effect Transistor
JIIC Junction Isolated Integrated Circuit
JPO Joint Program Office
LET Linear Energy Transfer
LINAC Linear Accelerator
LTH LET Threshold
MCT Multiple Collateral Threat
MFP Mean Free Path
MOS Metal Oxide Semiconductor
N Neutron fluence in n/cm2; 1 MeV eq.
NBC Nuclear, Biological and Chemical
NH&S Nuclear Hardness & Survivability
NMOS N-channel MOS
PCB Parts Control Board
PDC Preliminary Design Complete
PMOS P-channel MOS
PMPCB Parts, Materials, Processing Control Board
QAB Quality Assurance Board
rad Radiation Absorbed Dose
RF Radio frequency
RTVM Requirements Verification Tracking Matrix
S/V Space Vehicle
S/VAR Survivability Vulnerability Analysis Report
SDC System Design Complete
SEIT Systems Engineering Integration & Test
SETA Systems Engineering Test and Analysis
SFXR Super Flash X-ray
SGEMP System Generated Electromagnetic Pulse
SOS Silicon on Sapphire
SPAR System Performance Analysis Report
SRD Systems Requirements Document
SS Sample Size
SSS Spin Sun Sensor
TLD Thermoluminescent Dosimeter
TPD Terminal Protection Device
TRAC Transient Radiation Analysis by Computer
TREE Transient Radiation Effects on Electronics
TT&C Telemetry Tracking & Control
USAFSD U.S. Air Force Space Division
Z Atomic Number


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