Investigation of parameters of new MAPD-3NM silicon photomultipliers

In the presented work, the parameters of a new MAPD-3NM-II photodiode with buried pixel structure manufactured in cooperation with Zecotek Company are investigated. The photon detection efficiency, gain, capacitance and gamma-ray detection performance of photodiodes are studied. The SPECTRIG MAPD is used to measure the parameters of the MAPD-3NM-II and scintillation detector based on it. The obtained results show that the newly developed MAPD-3NM-II photodiode outperforms its counterparts in most parameters and it can be successfully applied in space application, medicine, high-energy physics and security.

20-inch photomultiplier tube timing study for JUNO

Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator neutrino detector now under construction at Jiangmen, Guangdong, China for determination of neutrino mass ordering with 3% energy resolution at 1 MeV, a precise measurement of neutrino oscillation parameters, and other neutrino physics. The central detector is made up of a 35.4-meter diameter acrylic sphere which contains 20 kton of liquid scintillator and is surrounded by about 18k 20-inch photomultiplier tubes (PMTs). The PMTs performance is one of the JUNO’s key successes to reach the high resolution goal. In this study, the PMT characteristic and its timing related responses were determined via the PMT generated signals, extracted from the PMT in a scanning station system. About 2,400 of micro-channel plate PMTs (MCP-PMTs) and dynode PMTs were analyzed for their responses with LED source such as rise time, fall time, transit time spread (TTS), gain, etc., which relate to photon incident on different positions of PMT’s glass surface. Furthermore, we also observed the fluctuation of PMT performance under magnetic field which can decrease the PMT photon detection efficiency (PDE).

Coded masks for imaging of neutrino events

The capture of scintillation light emitted by liquid Argon and Xenon under molecular excitations by charged particles is still a challenging task. Here we present a first attempt to design a device able to have a sufficiently high photon detection efficiency, in order to reconstruct the path of ionizing particles. The study is based on the use of masks to encode the light signal combined with single-photon detectors, showing the capability to detect tracks over focal distances of about tens of centimeters. From numerical simulations it emerges that it is possible to successfully decode and recognize signals, even of rather complex topology, with a relatively limited number of acquisition channels. Thus, the main aim is to elucidate a proof of principle of a technology developed in very different contexts, but which has potential applications in liquid argon detectors that require a fast reading. The findings support us to think that such innovative technique could be very fruitful in a new generation of detectors devoted to neutrino physics.

Measurement of the photon detection efficiency of silicon photomultipliers for the new detector cluster of the Cherenkov gamma-ray telescope TAIGA-IACT equipped with UV filters

This study was devoted to measurements of the UV-range photon detection efficiency (PDE) of OnSemi MicroFJ SiPM detectors use together with custom UV filters and of the transmission coefficient of these filters at 277 nm. The final goal of these measurements was to determine feasibility of the filters for the new detector cluster of the TAIGA-IACT telescope. PicoQuant PLS-270 UV source emitting pulses at 277 nm was calibrated. The obtained dependences of the registered radiation power on the distance between the emission source and the reference detector are well approximated by the inverse square function, hence no significant scattering or absorption influenced the PDE measurements. The dependences of the number of detected photons on the distance between the source and the detector were obtained. These dependencies are also well approximated by the inverse square function. The PDE of SiPM MicroFJ-60035 detector was measured at the level of 10.0 ± 0.7%. The transmission coefficients of the considered set of filters at the wavelength of 277 nm were also obtained. The SL 240-300 filter has a sufficiently high transmission coefficient and it is advisable to use it as a bandpass ultraviolet filter in the new detector cluster of the TAIGA-IACT telescope; the SL 290-590 filter absorbs ultraviolet light quite well and is applicable in the visible range.