New fast photomultipliers with a screening grid at the anode

New Photonis XP20D0 photomultiplier for fast timing in nuclear medicine

“…The usefulness of the screening grid at the anode was verified in the studies of two types of experimental PMTs, XP2020UR-M [18,19] and XP20Y0Q/DA [20]. In both the experiments done with fast NE111 plastic, and BaF 2 , LSO, LaCl 3 and NaI(Tl) crystals the improvement of timing by about a factor of 1.15-1.2 over standard PMTs, without grid, was observed.…”

“…The XP20Y0/DA is the prototype of XP20D0, tested earlier in Ref. [20], while XP20D0 tubes represent the current Photonis production. Note the high blue sensitivity of all tested PMTs.…”

“…Geometry of the last dynodes and the anode in the typical linearfocused photomultiplier. Note that the anode is built as a grid inside the last dynode [20]. The position of the screening grid is also shown.…”

Nuclear structure of 231Ac

“…The radioactive beam was deposited in the centre of the fast timing station specially designed to measure the half-life of excited states in the nanoand pico-second range by the Advanced Time Delayed (ATD) βγγ(t) method [19,21,22]. The setup of this station consisted of a 3 mm thick NE111A plastic scintillator positioned behind the tape at the collection point and used as fast-timing β-detector.…”

“…The Advanced Time Delayed (ATD) βγγ(t) technique detailed in [19,21,22] has been used to measure level lifetimes in 231 Ac. This method involves triple coincidences of β-BaF 2 -Ge events.…”