Changes

The ones that gave up a significant part of their energy to a gamma ray in the diamond are bent in a tighter orbit in the spectrometer than the rest, and come out of the spectrometer at the location indicated by the tagging detector (dark ellipse). These electrons correspond one-to-one with high-energy gammas (also called high-energy photons) in the photon beam (red line). The photon beam is not deflected by the magnetic field of the spectrometer, so it travels straight out the side of the magnet and is directed downstream toward the GlueX spectrometer. By lining up events in the GlueX spectrometer in time with electrons in the tagging detector, it is possible to "tag" the energy of each energetic photon that produces a high-energy interaction in the experiment. This technique of indirectly measuring the photon beam energy on a photon-by-photon basis by detecting the electron that created it is known as "photon tagging".

The ones that gave up a significant part of their energy to a gamma ray in the diamond are bent in a tighter orbit in the spectrometer than the rest, and come out of the spectrometer at the location indicated by the tagging detector (dark ellipse). These electrons correspond one-to-one with high-energy gammas (also called high-energy photons) in the photon beam (red line). The photon beam is not deflected by the magnetic field of the spectrometer, so it travels straight out the side of the magnet and is directed downstream toward the GlueX spectrometer. By lining up events in the GlueX spectrometer in time with electrons in the tagging detector, it is possible to "tag" the energy of each energetic photon that produces a high-energy interaction in the experiment. This technique of indirectly measuring the photon beam energy on a photon-by-photon basis by detecting the electron that created it is known as "photon tagging".