The angle correlation in e{sup +}e{sup {minus}} pair production by linear polarized photon was proposed for photon polarization measurements by Yang and Berlin and Madansky. An accurate QED calculation with analysis of the possible experimental setup was done by L Maximon and H. Olsen. The effect was used successfully for measurement of the beam polarization. The limitation of the method at photon energies above 100 MeV arises from the small value of an angle between pair components. They propose a new polarimeter for high energy photons based on the well known correlation in electron-positron pair production from an amorphous converter. The detector design utilizes silicon micro-strip detectors that allow the construction of a compact device useful in the few GeV photon energy range. The most important features of these detectors are the capability to detect two tracks separated by a very small distance ({approximately} 100 microns) and very good position resolution, ({approximately} a few microns). Because the typical opening angle in e{sup +}e{sup {minus}} pair is about 1/{gamma} and available space for a polarimeter is about 1 meter, the distance e{sup +}e{sup {minus}} is about a fraction of mm. It means that at the photon energies of interest, most of …

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.

Semiweekly newspaper from Pawhuska, Oklahoma that includes local, state, and national news along with advertising.