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PMT and WLS activities at IHEP. Vladimir Rykalin IHEP, Protvino CBM meeting JINR Dubna, 13-18 October 2008. Outline. The main reached and expected characteristics of PMT FEU-Hive for CBM RICH. Designed earlier and new constructions of PMT. Lacks of designed construction.
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PMT and WLS activities at IHEP Vladimir Rykalin IHEP, Protvino CBM meeting JINR Dubna, 13-18 October 2008
Outline • The main reached and expected characteristics of PMT FEU-Hive for CBM RICH. • Designed earlier and new constructions of PMT. • Lacks of designed construction. • Main elements of new construction. • Some measured characteristics of PMT-WLS film system.
Reached and expected characteristics of PMT FEU-HIVE-1 • #1 #8 #22 pr.#7 pr.#10 waiting • External PMT diameter, mm 7.5 7,6 7.8 7.4 7.5 6-7 • Photo-cathode diameter, mm 6 6,4 6.5 6.3 6.3 5-6 • PMT length is, mm 300 101 100 105 100 80 • Photo-cathode: K2CsSb • Quantum efficiency, 410 nm, % 4 5.1 14 28 24. 4 25 • Effective number of dynodes 12 • Nominal HV, kV 2.8 2.1 1.5 2 • Amplification 104 5×106 5×105 106 • Dynamical charge range, pC 3 0.25-2.5 • Noise current is, e/sec 40000 5000 3000 • Capacitance, pF 10 15 • Power dissipation, mW 0.25 40 • Price, Euro/PMT 25 Pr. #7, Pr. #9 – prototype samples of PMT-HIVE photocathodes producted in PMT-HIVE-1 glass cases without dynodes systems.
PMT FEU-Hive-1 and HAMAMATSU PMT R1828 signals: 76ns signals from LED Signals from single photoelectrons
The disadvantages of construction and production technology of PMT FEU-HIVE-1 • Lead-in contacts (Kovar rings)leavingon outside surface of PMT case creates difficulties for connections to PMT contacts in case of photodetector plane. • Technology of glass case-Kovar rings welding is very delicate process that demands the special equipment. Absence of this equipment leads to considerable marriage at carrying out of manual welding. • Production of Kovar rings, preparation rings and glass cases to welding are not cheap and simple operations. • Technology of evaporation of dynode active layer is very unstable. • This items are cause of design of the new PMT FEU-HIVE-2 construction and changes of some technological operation.
Status of PMT FEU-HIVE-2 • Construction (drawings) of PMT is designed. • Elements of construction are in production. • The new technology of evaporation of dynode active layer is designed.
. Time characteristics of WLS film
Plan of works on PMT FEU-HIVE and WLS at 2008 and 2009 • Production of the first samples of FEU-HIVE-2 -end 2008. • Production of few tens samples -end 2009 of FEU-HIVE-2 and study their characteristics. • Study of WLS film efficiency in -end 2009 the optical region 120nm-400nm. The main condition of performance of works is a financing of works.