High-efficient pair magnetic spectrometer

A magnetic pair spectrometer for γ rays using a spark chamber is described. The spectrometer has been calibrated with a monochromatic beam of 120-MeV γ rays. For a target thickness of 0.014 X"0 the resolution is 1.5%. We have studied the possibility of using the spectrometer with a thick target...
Ausführliche Beschreibung

A magnetic pair spectrometer for γ rays using a spark chamber is described. The spectrometer has been calibrated with a monochromatic beam of 120-MeV γ rays. For a target thickness of 0.014 X"0 the resolution is 1.5%. We have studied the possibility of using the spectrometer with a thick target (up to 0.3 X"0) without appreciable loss of resolution. For this purpose the ionization and bremsstrahlung losses of the pair were measured with NaI(Tl) counters. For an effective target, of thickness 0.1 X"0, the resolution is 2.3% and the efficiency 6%. Ausführliche Beschreibung