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Time-of-flight diffraction (TOFD) method of ultrasonic testing is a sensitive and accurate method for the nondestructive testing of welds for defects. TOFD originated from tip diffraction techniques which were first published by Silk and Liddington [1] in 1975 which paved the way for TOFD. Later works on this technique are given in a number of ...
Time of flight (ToF) is the measurement of the time taken by an object, particle or wave (be it acoustic, electromagnetic, etc.) to travel a distance through a medium. This information can then be used to measure velocity or path length, or as a way to learn about the particle or medium's properties (such as composition or flow rate).
From the time of flight, the phase velocity can be determined as a function of the angle of incidence of the ultrasonic pulse. Using Christoffel 's equations, the measured data can be fitted using a least squares numeric method to determine six of the nine elastic constants.
A time-of-flight (TOF) detector is a particle detector which can discriminate between a lighter and a heavier elementary particle of same momentum using their time of flight between two scintillators [1]. The first of the scintillators activates a clock upon being hit while the other stops the clock upon being hit.
A time-of-flight mass spectrometer (TOFMS) consists of a mass analyzer and a detector. An ion source (either pulsed or continuous) is used for lab-related TOF experiments, but not needed for TOF analyzers used in space, where the sun or planetary ionospheres provide the ions. The TOF mass analyzer can be a linear flight tube or a reflectron.
Today, most neutron scattering experiments are performed by research scientists who apply for beamtime at neutron sources through a formal proposal procedure. Because of the low count rates involved in neutron scattering experiments, relatively long periods of beam time (on the order of days) are usually required for usable data sets.
Time-of-flight spectrometers at pulsed sources include Pharos at LANSCE's Lujan Center at Los Alamos National Laboratory, MAPS, MARI, HET, MERLIN and LET at the ISIS neutron source, and ARCS, CNCS, and SEQUOIA at the Spallation Neutron Source, [1] iBIX, SuperHRPD, PLANET, SENJU, TAKUMI, iMATERIA and NOVA at the J-PARC and SKAT-EPSILON, DIN-2PI, NERA at the IBR-2 pulsed reactor.
Its size made it the target of three-quarters of the sample measurements taken in the first 25 years of the experiment. Improvements in technology since then have resulted in greater use of the smaller arrays, by sites such as the Côte d'Azur Observatory in Nice, France; and the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO ...