A high efficiency electron pair spectrometer

Autor: Birk, M., Sokolowski, J.S., Wolfson, Y., Benczer-Koller, N.
Zdroj: Nuclear Instruments and Methods in Physics Research; December 1982, Vol. 203 Issue: 1-3 p255-259, 5p
Abstrakt: a multi-detector high efficiency spectrometer for the detection of electron-positron pairs in the presence of high intensity gamma radiation has been designed, built and tested. The spectrometer employs six RCA 8850 photomultipliers. A “sandwich” made of a 0.5 mm thick anthracene glued to the front face of a 45 mm thick NE 102A plastic scintillator was mounted on each photomultiplier. A pulse shape discrimination circuit distinguishes electron from gamma signals, making use of the fact that electrons produce a relatively long scintillation pulse (≈ 25 nrmns) in the anthracene, whereas gammas have a negligible probability to interact with the thin anthracene. The six scintillators cover a solid angle of 3.2 π sr around the target and their front surfaces form nine boundary lines. An annular Si(Li) detector (0.081 sr) used to detect particles backscattering from the target may be operated in coincidence with the electron detector.
Databáze: Supplemental Index