Sound amplification by stimulated emission of radiation was first experimentally demonstrated in the Gigahertz range in 2009. Announced in 2010, two independent groups came up with two different devices that produce coherent phonons at any frequency in the range megahertz to terahertz. One group from the University of Nottingham consisted of A.J. Kent and his colleagues R.P. Beardsley, A.V. Akimov, W. Maryam and M. Henini. The other group from the California Institute of Technology (Caltech) consisted of Ivan S. Grudinin, Hansuek Lee, O. Painter and Kerry J. Vahala from Caltech implemented a study on Phonon Laser Action in a tunable two-level system. The University of Nottingham device
Neutron stimulated emission computed tomography sample with neutrons, the measured number of emitted gamma rays of energy characteristic to the nucleus of interest is directly proportional to the number of such nuclei along the incident neutron beam trajectory. After repeating the measurement for neutron beam incidence at positions around the sample, an image of the distribution of the nuclei in the sample can be reconstructed as done in tomography. Neutron stimulated emission computed tomography Neutron stimulated emission computed tomography (NSECT) uses induced gamma emission through neutron inelastic scattering to generate images of the spatial distribution of elements in a sample. NSECT has been shown to