time of flight


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time of flight

the time for a photon created by annihilation of a positron-electron pair to reach a detector; because annihilation photons are created in pairs and travel in opposite directions at about 3 × 1010 cm/sec, measurement of the difference in arrival time at detectors with subnanosecond resolution allows calculation of the location of the event; the basic physics of positron emission tomography.

time of flight

An MRI term referring to a magnetic resonance angiography technique based solely on the flow of unsaturated blood into a magnetised presaturated slice. The difference between the unsaturated and presaturated spins creates a bright vascular image without needing contrast media.

time of flight

(tīm flīt)
magnetic resonance imaging Rate of flow in a given time; causes some flowing nuclei to receive only one radiofrequency pulse and therefore produce a signal void.
References in periodicals archive ?
the pulsed beam allows systematic effects to be isolated by their different time of flight dependences;
Atmospheric Pressure Interface Time of Flight Mass Spectrometer to be used in the Atmospheric Aerosol Research.
today introduced the 7200B Quadrupole Time of Flight (Q-TOF) Gas Chromatography Mass Spectrometer (GC/MS) System.
Contract notice: Acquisition of a real-time analyzer mass spectrometry (ms) by proton transfer (ptr), multiple reactant ions (sri), to guide ions by quadrupole (qi) and time of flight (tof).
Acquisition of a photoelectron spectrometer time of flight resolved angle (Angle Resolved Time Of Flight spectrometer, Artof) for measuring the electronic band structure of solids, with ultra-high vacuum test chamber.
Contract notice: Time of flight secondary ion mass spectrometer system (tof-sims).
Contract notice: Proton exchange reaction time of flight mass spectrometer.