Speaker
Dr
Ettore Segreto
(INFN)
Description
A new generation, high Quantum Efficiency 3" photomultiplier tube (PMT) for
cryogenic applications at liquid Argon temperature (LAr, T=87 K) has been recently
developed by Hamamatsu Photonics (Mod. R11065). This issue is of interest in
particular for direct Dark Matter searches with detectors adopting liquified Argon
as nuclear targets for WIMP interactions and read-out of the corresponding
scintillation light signals from nuclear recoil in the medium. Improvements in
detector sensitivity down to low recoil energy thresholds can be primarily achieved
by using these new PMTs with enhanced quantum efficiency.
Within the on-going R&D activity of the WArP Collaboration (WIMP Argon Program at
the INFN GranSasso Lab), a first set of R11065 PMTs has been subject to a series of
tests aiming at their characterization in reference working conditions. These were
obtained by operating the PMTs immersed in the liquid and optically coupled to LAr
cells of various size. A comparison of the R11065 Hamamatsu PMT with a former
generation of cryogenic PMT (currently in use with the WArP-100 detector), has been
also carried out with the two PMTs simultaneously operated and viewing a common LAr volume.
From these tests the superior performances of the Hamamatsu PMT have been clearly
demonstrated, showing that this new type of PMT is very well suited for experimental
applications, in particular for new direct Dark Matter searches with LAr-based
experiments.
Authors
Dr
Andrzej Szelc
(Yale University)
Dr
Ettore Segreto
(INFN)
Prof.
Flavio Cavanna
(Università degli studi di L'Aquila)
Dr
Nicola Canci
(INFN)
Dr
Roberto Acciarri
(Università degli studi di L'Aquila)
