• Tsubuku, Y.
• Shimokawabe, T.
• Okada, T.
• Ohtsu, I.
• Toizumi, T.
• Inagawa, S.
• Kataoka, J.
• Nakamori, T.
• Kawai, N.

Abstract

We report on the performance testing of a multi-anode photomultiplier (MAPMT), the R8900-200-M16MOD-UBA, newly developed by Hamamatsu Photonics K.K. Although the R8900 series offers the great advantage of a highly sensitive surface (&ges;80% of physical area), the quantum efficiency (Q.E.) was relatively low (at up to 20%). This paper describes two substantial changes we have made to the R8900-200-M16MOD-UBA: (1) improving the Q.E. to the 40% level by employing an ultra bi-alkali (UBA) photo-cathode and (2) constructing a rugged dynode that can withstand vibration for future use in space. We measured each pixel signal at the single photoelectron level and the signals of scintillation photons by using a 16-pixel plastic scintillator array. Thanks to high Q.E., good energy resolution of 29.9% (FWHM) was obtained for 59.5 keV &gamma;-rays. We also demonstrated tolerance to vibration up to 17G<SUB>rms</SUB> in possible launching vehicles.

Topics

• surface
• polymer