Optical modules for the neutrino telescope KM3NeT Kalekin, O.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
KM3NeT is a future deep-sea research infrastructure hosting a neutrino telescope with a volume of at least one cubic kilometer to be constructed in the Mediterranean Sea. The experiment aims to ...detect high-energy cosmic neutrinos using a 3D array of optical modules to collect the Cherenkov light induced by charged particles in the water. Upward going muons and showers produced in neutrino interactions with the surrounding matter will allow the search and study of possible sources of extra-terrestrial neutrinos. The design of optical modules makes an important impact on the performance and cost of the KM3NeT project. Several different optical module configurations are under consideration; based on glass pressure spheres containing: a large (10in.) hemispherical photomultiplier tube (with a multi-anode version as an option); 25–31 3in. photomultiplier tubes, or a crystal scintillator-based hybrid device (X-HPD). The features and advantages of each optical module design are discussed.
PMT characterisation for the KM3NeT project Herold, B.; Kalekin, O.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2011, Letnik:
626
Journal Article
Recenzirano
KM3NeT is a future neutrino telescope in the Mediterranean Sea with at least 1
km
3 of instrumented volume. During the current design stage, 3-, 8- and 10-in. photomultiplier tubes from Hamamatsu and ...ET Enterprises have been investigated as candidates for the telescope's optical modules. The most important parameters of these photomultiplier tubes, such as the time resolution, the absolute quantum efficiency of the photocathode, the inhomogeneity of the overall efficiency over the photocathode and the resulting effective photocathode area, have been measured in a test bench at the Erlangen Centre for Astroparticle Physics. These results are presented.
The Cherenkov Telescope Array (CTA) is a future gamma-ray observatory that is planned to significantly improve upon the sensitivity and precision of the current generation of Cherenkov telescopes. ...The observatory will consist of several dozens of telescopes with different sizes and equipped with different types of cameras. Of these, the FlashCam camera system is the first to implement a fully digital signal processing chain which allows for a traceable, configurable trigger scheme and flexible signal reconstruction. As of autumn 2016, a prototype FlashCam camera for the medium-sized telescopes of CTA nears completion. First results of the ongoing system tests demonstrate that the signal chain and the readout system surpass CTA requirements. The stability of the system is shown using long-term temperature cycling.
•A full-scale prototype of the FlashCam Cherenkov camera is in operation.•System level testing and characterisation in a dark room is ongoing.•The performances of the data acquisition and the signal chain have been verified.•The system is stable over long periods and robust against temperature variations.
PMT characterisation for the KM3NeT project Herold, B.; Kalekin, O.; Reubelt, J.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Letnik:
639, Številka:
1
Journal Article
Recenzirano
The KM3NeT project aims to design and to construct at least a cubic kilometre scale neutrino telescope in the Mediterranean Sea. The main task is to instrument this deep-sea water volume with optical ...modules, each housing one or several photomultiplier tubes. Three-, 8- and 10-in. PMTs from ET Enterprises, Hamamatsu and MELZ-FEU have been investigated as candidates for the telescope's optical modules. Various parameters of these photomultiplier tubes have been measured in a test bench at the Erlangen Centre for Astroparticle Physics. These results are presented.
Abstract
The observation of electromagnetic radiation from radio to γ-ray wavelengths has provided a wealth of information about the Universe. However, at PeV (10
15
eV) energies and above, most of ...the Universe is impenetrable to photons. New messengers, namely cosmic neutrinos, are needed to explore the most extreme environments of the Universe where black holes, neutron stars, and stellar explosions transform gravitational energy into non-thermal cosmic rays. These energetic particles have millions of times higher energies than those produced in the most powerful particle accelerators on Earth. As neutrinos can escape from regions otherwise opaque to radiation, they allow an unique view deep into exploding stars and the vicinity of the event horizons of black holes. The discovery of cosmic neutrinos with IceCube has opened this new window on the Universe. IceCube has been successful in finding first evidence for cosmic particle acceleration in the jet of an active galactic nucleus. Yet, ultimately, its sensitivity is too limited to detect even the brightest neutrino sources with high significance, or to detect populations of less luminous sources. In this white paper, we present an overview of a next-generation instrument, IceCube-Gen2, which will sharpen our understanding of the processes and environments that govern the Universe at the highest energies. IceCube-Gen2 is designed to:
(a) Resolve the high-energy neutrino sky from TeV to EeV energies
(b) Investigate cosmic particle acceleration through multi-messenger observations
(c) Reveal the sources and propagation of the highest energy particles in the Universe
(d) Probe fundamental physics with high-energy neutrinos
IceCube-Gen2 will enhance the existing IceCube detector at the South Pole. It will increase the annual rate of observed cosmic neutrinos by a factor of ten compared to IceCube, and will be able to detect sources five times fainter than its predecessor. Furthermore, through the addition of a radio array, IceCube-Gen2 will extend the energy range by several orders of magnitude compared to IceCube. Construction will take 8 years and cost about $350M. The goal is to have IceCube-Gen2 fully operational by 2033.
IceCube-Gen2 will play an essential role in shaping the new era of multi-messenger astronomy, fundamentally advancing our knowledge of the high-energy Universe. This challenging mission can be fully addressed only through the combination of the information from the neutrino, electromagnetic, and gravitational wave emission of high-energy sources, in concert with the new survey instruments across the electromagnetic spectrum and gravitational wave detectors which will be available in the coming years.
The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for cosmic gamma rays. The FlashCam camera for its mid-size telescope introduces a new concept, with a modest ...sampling rate of 250 MS/s, that enables a continuous digitization as well as event buffering and trigger processing using the same front-end FPGAs. The high performance Ethernet-based readout provides a dead-time free operation for event rates up to 30 kHz corresponding to a data rate of 2.0 GByte/s sent to the camera server. We present the camera design and the current status of the project.
Context. Very high-energy (VHE, E > 100 GeV) γ-ray data are a valuable input for multi-wavelength and multi-messenger (e.g. combination with neutrino data) studies. Aims. We aim at the conservation ...and homogenization of historical, current, and future VHE γ-ray-data on active galactic nuclei (AGN). Methods. We have collected lightcurve data taken by major VHE experiments since 1991 and combined them into long-term lightcurves for several AGN, and now provide our collected datasets for further use. Due to the lack of common data formats in VHE γ-ray astronomy, we have defined relevant datafields to be stored in standard data formats. The time variability of the combined VHE lightcurve data was investigated, and correlation with archival X-ray data collected by RXTE/ASM tested. Results. The combination of data on the prominent blazar Mrk 421 from different experiments yields a lightcurve spanning more than a decade. From this combined dataset we derive an integral baseline flux from Mrk 421 that must be lower than 33% of the Crab Nebula flux above 1 TeV. The analysis of the time variability yields log-normal flux variations in the VHE-data on Mrk 421. Conclusions. Existing VHE data contain valuable information concerning the variability of AGN and can be an important ingredient for multi-wavelength or multi-messenger studies. In the future, upcoming and planned experiments will provide more data from many transient objects, and the interaction of VHE astronomy with classical astronomy will intensify. In this context a unified and exchangeable data format will become increasingly important.
Status of the PMT development for KM3NeT Classen, L.; Kalekin, O.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2013, Letnik:
725
Journal Article
Recenzirano
KM3NeT is a future large volume (multi km3) neutrino telescope to be constructed at the bottom of the Mediterranean Sea. The detection volume will be instrumented using multi-PMT optical modules, ...consisting of an array of small photomultipliers housed in a spheric glass vessel. Three companies are presently developing 3-in. PMTs as candidates for the construction of these modules. Main characteristics of the prototypes, such as quantum efficiency, single electron gain, dark current and transit time spread, are required to meet the specification established by the KM3NeT consortium.
We report on the current stage of PMT development and recent results of tests performed at the Erlangen Centre for Astroparticle Physics.
The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy in-fill extension to the IceCube Neutrino Observatory. With detection technology modeled closely on the successful ...IceCube example, PINGU will provide a 6 Mton effective mass for neutrino detection with an energy threshold of a few GeV. With an unprecedented sample of over 60 000 atmospheric neutrinos per year in this energy range, PINGU will make highly competitive measurements of neutrino oscillation parameters in an energy range over an order of magnitude higher than long-baseline neutrino beam experiments. PINGU will measure the mixing parameters θ 23 and Δ m 32 2 , including the octant of θ 23 for a wide range of values, and determine the neutrino mass ordering at 3 median significance within five years of operation. PINGU's high precision measurement of the rate of τ appearance will provide essential tests of the unitarity of the 3 × 3 PMNS neutrino mixing matrix. PINGU will also improve the sensitivity of searches for low mass dark matter in the Sun, use neutrino tomography to directly probe the composition of the Earth's core, and improve IceCube's sensitivity to neutrinos from Galactic supernovae. Reoptimization of the PINGU design has permitted substantial reduction in both cost and logistical requirements while delivering performance nearly identical to configurations previously studied.
PMT measurements in Antares Creusot, A.; Kalekin, O.; Kulikovskiy, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2013, Letnik:
725
Journal Article
Recenzirano
The comparison of simulated and real data in the Antares experiment shows some discrepancies. Differences are observed in the charge distribution of background hits, in the trigger efficiency, and in ...the counting rate of 40K decay induced events. These discrepancies must be understood to improve data analysis. It turns out that most of the simulated/real data mismatch can be explained by a undetailed description of the PMT response in the simulations. PMT parameters such as late pulses, afterpulses and angular acceptance have been reviewed and when necessary measurements of these parameters have been carried out using Antares PMTs and optical modules. In addition a more detailed simulation of the angular acceptance of the Antares optical module has been performed. Results of these studies are presented.
PDF
