R331-05

PHOTOMULTIPLIER TUBES R331, R331-05 For Liquid Scintillation Counting Bialkali Photocathode, 51mm (2 Inch) Diameter, 12 Stages, Head-On Type The R331 and the R331-05 are 51mm (2 Inch) diameter series photomultiplier tubes specifically developed for the liquid scintillation counting. They feature low background noise, high tritium efficiency, good linearity and high gain. The R331 uses a synthetic silica input window and the R331-05 uses a low K content borosilicate glass input window, both with a frosted surface and convex-concave shape. They offer minimized glass scintillations and high collection efficiency. FEATURES Tritium efficiency in tritium window................................ 60% Typ. Background noise in tritium window...............16cpm Typ. (R331) 18cpm Typ. (R331-05) Tritium end point (T.E.P.) voltage.................................. 1700V Typ. Dark pulse summation at T.E.P. voltage.............. 3 × 104cpm Max. Figure of merit (E2/B).......................................................... 200 Typ. GENERAL Parameter Spectral Response Wavelength of Maximum Response Photocathode Window Material Dynode Direct Material Minimum Useful Area Material Shape Structure Number of Stages Anode to Last Dynode R331 160 to 650 420 Bialkali R331-05 300 to 650 Unit nm nm — CATHODE RADIANT SENSITIVITY (mA/W) QUANTUM EFFICIENCY (%) Figure 1: Typical Spectral Response TPMHB0505EA 100 R331 CATHODE RADIANT SENSITIVITY mm dia. 46 Synthetic silica Low K content — borosilicat...