Search results for "Dark current"
showing 5 items of 15 documents
Search for Supernova Neutrino-Bursts with the AMANDA Detector
2001
The core collapse of a massive star in the Milky Way will produce a neutrino burst, intense enough to be detected by existing underground detectors. The AMANDA neutrino telescope located deep in the South Pole ice can detect MeV neutrinos by a collective rate increase in all photo-multipliers on top of dark noise. The main source of light comes from positrons produced in the CC-reaction of anti-electron neutrinos on free protons $\antinue + p \to e^+ + n$. This paper describes the first supernova search performed on the full sets of data taken during 1997 and 1998 (215 days of live time) with 302 of the detector's optical modules. No candidate events resulted from this search. The performan…
Silicon photomultiplier properties at cryogenic temperatures
2015
Abstract The properties of different types of silicon photomultipliers (SiPMs) were studied at cryogenic temperatures. In liquid nitrogen at 77 K, problems with quenching in Hamamatsu SiPMs and with the protective epoxy layer, covering Zecotek SiPMs, were observed. Tests with one Zecotek SiPM were successful after removal of the epoxy layer. In liquid helium at 4 K, fast signals with pulse lengths shorter than 50 ns were observed, the dark count rate was below 10 Hz and no after-pulses were detected. The gain, as a function of over-voltage, was comparable to room temperature. The SiPM׳s response to photons was found to be linear with intensity for low light levels and single-photon detectio…
A Wavelength-shifting Optical Module (WOM) for in-ice neutrino detectors
2016
7th Very Large Volume Neutrino Telescope Workshop, Rome, Italy, 14 Sep 2015 - 16 Sep 2015 ; The European physical journal / Web of Conferences 116, 01006 (2016). doi:10.1051/epjconf/201611601006
Preliminary radiation hardness tests of single photon Si detectors
2010
Single photon Si detectors were fabricated by STMicroelectronics and fully characterized in standard operation conditions and after irradiations. Both single cells and arrays, of dimensions ranging from 5x5 up to 64x64, were electrically tested. The devices operation was studied as a function of the temperature from -25 degrees C to 65 degrees C varying the voltage over breakdown, from 5% up to 20% of the breakdown voltage before and after irradiation using both light ions, 10 MeV B ions to doses in the range 3x10(7)-5x10(10) cm(-2), and X-rays irradiations in the range 0.5-20 krad(Si). Optical characterization was performed using a laser at 659 nm and opportunely chosen filters to vary the…
Dynamical analysis of electron transport in RF cavities and photomultipliers tubes
2021
El objetivo de este trabajo es el estudio de la dinámica de haces y corrientes de electrones en cavidades aceleradoras de radiofrecuencia (RF) y en tubos fotomultiplicadores. Por una parte, los haces de electrones presentan una gran importancia histórica tanto en aplicaciones directas (televisiones, hornos de microondas, tratamiento del cáncer), como en la generación de radiación sincrotrón. La última generación de fuentes de rayos X muy brillantes se basa en los láseres de electrones libres (XFEL). No obstante, para producir los haces de electrones que emitirán dichos rayos X como radiación sincrotrón, se necesitan campos eléctricos de gran intensidad lo que produce que, debido a la emisió…