| CTT | cefotetan; central tegmental tract; central transmission time; compressed tablet triturate; computer... |
|---|---|
| DT | defibillation threshold; delirium tremens; dental technician; depression of transmission; dietetic [... |
| IVT | index of vertical transmission; interventional video tomography; intrasound vibration test; intraven... |
| NMT | neuromuscular tension; neuromuscular transmission; N-methyltransferase; N-myristoyltransferase; no m... |
| PTI | pancreatic trypsin inhibitor; persistent tolerant infection; Pictorial Test of Intelligence; placent... |
| conversion electron | An internal conversion electron. (05 Mar 2000) |
|---|---|
| positive electron | A subatomic particle of mass and charge equal to the electron but of opposite (i.e., positive) charge. Synonym: positive electron. (05 Mar 2000) |
| scanning electron microscope | <instrument> An electron microscope in which the image is formed by a beam synchronised with an electron probe scanning the object. The intensity of the image forming beam is proportional to the scattering or secondary emission of the specimen where the probe strikes it (05 Aug 1998) |
| secondary electron | <microscopy> Produced by an incident electron passing near an atom in the specimen, near enough to impart some of its energy to a lower energy electron (usually in the K-shell). This causes a slight energy loss and path change in the incident electron and the ionisation of the electron in the specimen atom. This ionised electron then leaves the atom with a very small kinetic energy (5eV) and is then termed a secondary electron. Each incident electron can produce several secondary electrons. (05 Aug 1998) |
| secondary electron imaging | <microscopy> Production of secondary electrons is very topography related. Due to their low energy, 5eV, only secondaries that are very near the surface (less than 10nm) can exit the sample and be examined. Any changes in topography in the sample that are larger than this sampling depth will change the yield of secondaries due to collection efficiencies. Collection of these electrons is aided by using a collector in conjunction with the secondary electron detector. The collector is a grid or mesh with a +100V potential applied to it which is placed in front of the detector, attracting the negatively charged secondary electrons to it which then pass through the grid-holes and into the detector to be counted. When a Secondary Electrons collide with the solid-state saemiconductor detector an electron-hole pairs are created which are then counted. This quantity is translated into a pixel intensity and displayed on the CRT, forming the image. (05 Aug 1998) |
| Selected Area Electron Diffraction | <technique> In this diffraction mode an aperture is used to define the area from which a diffraction pattern is to be recorded from a thin sample. This aperture is typically located in an image plane below the sample. Selected Area Electron Diffraction patterns are simple spot patterns and are of use in phase determination (lattice spacing measurement) and defect analysis (sample orientation). Acronym: SAED (05 Aug 1998) |
| internal conversion electron | An electron, similar to an Auger electron, released from one of the electron orbits of the atom upon activation by a gamma-ray from that atom's nucleus; the electron has kinetic energy equal to the net energy transition of the disintegration. (05 Mar 2000) |
| electron | <chemistry, physics> A stable atomic particle that has a negative charge, the flow ofelectrons through a substance constitutes electricity. (19 Jan 1998) |
| electron acceptor | <chemistry> A molecule or compound that gets electrons during an oxidation-reduction reaction. (19 Jan 1998) |
| electron beam | <microscopy> A stream of electrons in an electron optical system. (05 Aug 1998) |
| electron capture | <radiobiology> Nuclear decay process whereby a proton in the nucleus absorbs an orbiting electron and converts to a neutron. (09 Oct 1997) |
| electron carrier | <chemistry> A protein which can either accept or donate electrons in oxidation-reduction reactions. (19 Jan 1998) |
| Electron Channeling Pattern | <microscopy> A pattern formed by the periodic backscattering of electrons by the specimen lattice in a transmission electron microscope. Allows determination of crystal structure and lattice parameters in crystals greater than 10 micrometres diameter. Acronym: ECP (05 Aug 1998) |
| electron cyclotron discharge cleaning | Using relatively low power microwaves (at the electron cyclotron frequency) to create a weakly ionised, essentially unconfined hydrogen plasma in the vacuum chamber. The ions react with impurities on the walls of the tokamak and help remove them from the chamber. For instance, Alcator C-mod typically applies electron cyclotron discharge cleaning for a few days prior to beginning a campaign, and a few hours before each day's run. (09 Oct 1997) |
| electron cyclotron emission | <physics, radiobiology> As electrons gyrate around in a magnetic field (see also larmor radius or cyclotron radius), they radiate radio-frequency electromagnetic waves. This is known as electron cyclotron emission, and can be measured to help diagnose a plasma. (09 Oct 1997) |