Influence of wavelength-shifting films on multianode PMTs with UV-extended windows

• DOI: 10.1016/j.nima.2015.02.014
• Publication Date: 2015-02-14T02:00:50Z
• Authors: J. Adamczewski-Musch; K.-H. Becker; S. Belogurov; N. Boldyreva; A. Chernogorov; C. Deveaux; V. Dobyrn; M. Dürr; J. Eom; J. Eschke; C. Höhne; K.-H. Kampert; V. Kleipa; L. Kochenda; B. Kolb; J. Kopfer; P. Kravtsov; S. Lebedev; E. Lebedeva; E. Leonova; S. Linev; T. Mahmoud; J. Michel; N. Miftakhov; Y. Nam; W. Niebur; K. Oh; E. Ovcharenko; C. Pauly; J. Pouryamout; S. Querchfeld; J. Rautenberg; S. Reinecke; Y. Riabov; E. Roshchin; V. Samsonov; J. Song; O. Tarasenkova; T. Torres de Heid...; M. Traxler; C. Ugur; E. Vznuzdaev; M. Vznuzdaev; J. Yi; I.-K. Yoo
• Keywords: Quantum Efficiency; Photoelectric effect

Abstract Wavelength-shifting (WLS) films were applied on UV-extended front windows of multianode photomultiplier tubes (MAPMTs) in order to increase the sensitivity of the MAPMTs at shorter wavelengths. The WLS material contained p-Terphenyl as photoactive component, which absorbs shorter wavelength photons ( 300 nm ) and re-emits fluorescence photons around 350 nm, i.e., at the maximum of the PMTs׳ sensitivity. The films were applied by means of dip-coating and the film performance was studied with respect to quantum efficiency, film homogeneity, and crosstalk on the MAPMTs. Using WLS-film-covered MAPMTs in a gaseous Ring Imaging Cherenkov detector, the number of detected photoelectrons per ring increased by up to 21% in an in-beam test.