A new solution for mirror coating in γ-ray Cherenkov astronomy

Bonardi, A.; Pühlhofer, G.; Hermanutz, S.; Santangelo, A.

doi:10.1007/s10686-014-9398-x

Cited by 10 publications

(8 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As mentioned in the introduction, a typical example is CTA, in which SiPMs are used for the detection of the faint Cherenkov emission in the atmosphere caused by cosmic radiation, in the presence of a significant amount of night sky background, “NSB”, light. Since the Cherenkov signal has a low intensity, the PDE should be as high as possible in the spectral region of interest, which is estimated between 300 nm and 600 nm [29,30]. Similarly to many experiments, CTA requires reduction of correlated noise, including crosstalk and afterpulsing, to reduce ENF and, thus, improve energy resolution.…”

Section: Nuv-hd Low-crosstalkmentioning

confidence: 99%

NUV-Sensitive Silicon Photomultiplier Technologies Developed at Fondazione Bruno Kessler

Gola

Acerbi

Capasso

et al. 2019

Sensors

170

View full text Add to dashboard Cite

Different applications require different customizations of silicon photomultiplier (SiPM) technology. We present a review on the latest SiPM technologies developed at Fondazione Bruno Kessler (FBK, Trento), characterized by a peak detection efficiency in the near-UV and customized according to the needs of different applications. Original near-UV sensitive, high-density SiPMs (NUV-HD), optimized for Positron Emission Tomography (PET) application, feature peak photon detection efficiency (PDE) of 63% at 420 nm with a 35 um cell size and a dark count rate (DCR) of 100 kHz/mm2. Correlated noise probability is around 25% at a PDE of 50% at 420 nm. It provides a coincidence resolving time (CRT) of 100 ps FWHM (full width at half maximum) in the detection of 511 keV photons, when used for the readout of LYSO(Ce) scintillator (Cerium-doped lutetium-yttrium oxyorthosilicate) and down to 75 ps FWHM with LSO(Ce:Ca) scintillator (Cerium and Calcium-doped lutetium oxyorthosilicate). Starting from this technology, we developed three variants, optimized according to different sets of specifications. NUV-HD–LowCT features a 60% reduction of direct crosstalk probability, for applications such as Cherenkov telescope array (CTA). NUV-HD–Cryo was optimized for cryogenic operation and for large photosensitive areas. The reference application, in this case, is the readout of liquid, noble-gases scintillators, such as liquid Argon. Measurements at 77 K showed a remarkably low value of the DCR of a few mHz/mm2. Finally, vacuum-UV (VUV)-HD features an increased sensitivity to VUV light, aiming at direct detection of photons below 200 nm. PDE in excess of 20% at 175 nm was measured in liquid Xenon. In the paper, we discuss the specifications on the SiPM related to different types of applications, the SiPM design challenges and process optimizations, and the results from the experimental characterization of the different, NUV-sensitive technologies developed at FBK.

show abstract

Section: Nuv-hd Low-crosstalkmentioning

confidence: 99%

NUV-Sensitive Silicon Photomultiplier Technologies Developed at Fondazione Bruno Kessler

Gola

Acerbi

Capasso

et al. 2019

Sensors

170

View full text Add to dashboard Cite

show abstract

“…The generation of H 2 O 2 was detected by Ghormley’s triiodide method 32 : the standard samples were prepared by diluting the H 2 O 2 to obtain different concentrations; then 0.1 mL of the KI solution and 0.1 mL of the ammonium molybdate solution was added, and leaving it to react for 10 min, after which the UV intensity at 350 nm was measured 33 .…”

Section: Methodsmentioning

confidence: 99%

Singlet Oxygen Sensor Green is not a Suitable Probe for 1O2 in the Presence of Ionizing Radiation

Liu

Carter

Laan

et al. 2019

Sci Rep

View full text Add to dashboard Cite

A great number of fluorescent probes have been developed for detecting singlet oxygen ( 1 O 2 ), which is considered to be one of the most effective reactive oxygen species (ROS), especially in clinical applications. The commercially available fluorescent probe Singlet Oxygen Sensor Green (SOSG) is widely used due to its reported high selectivity to 1 O 2 . In this study, we carried out systemic experiments to determine the activation of SOSG in the presence of ionizing radiation. The results show that the SOSG probe exhibits a pronounced fluorescence increase as a function of radiation dose delivered by gamma-rays as well as X-rays, in conditions where the formation of singlet oxygen is not expected. Furthermore, scavenger tests indicate that hydroxyl radicals may be involved directly or indirectly in the activation process of SOSG although the exact mechanism remains unknown.

show abstract

“…To help understand the performance and characteristics of the Light-Trap, a simple simulation of the system was created using the Geant4 software simulation package (version 4.10.01-p02) [4]. A 15mm disk (optically perfect) with the absorption and emission properties of the EJ-299-15 material provided by Eljen was simulated.…”

Section: Simulationsmentioning

confidence: 99%

Light-Trap: a SiPM upgrade for VHE astronomy and beyond

2016

View full text Add to dashboard Cite

A: Ground-based gamma-ray astronomy in the Very High Energy (VHE, E>100 GeV) regime has fast become one of the most interesting and productive sub-fields of astrophysics today. Utilizing the Imaging Atmospheric Cherenkov Technique (IACT) to reconstruct the energy and direction of incoming gamma-ray photons from the universe, several source-classes have been revealed by previous and current generations of IACT telescopes (e.g. Whipple, MAGIC, HESS and VERITAS). The next generation pointing IACT experiment, the Cherenkov Telescope Array (CTA), will provide increased sensitivity across a wider energy range and with better angular resolution.With the development of CTA, the future of IACT pointing arrays is being directed towards having more and more telescopes (and hence cameras), and therefore the need to develop low-cost pixels with acceptable light-collection efficiency is clear.One of the primary paths to the above goal is to replace Photomultiplier Tubes (PMTs) with Silicon-PMs (SiPMs) as the pixels in IACT telescope cameras. However SiPMs are not yet mature enough to replace PMTs for several reasons: sensitivity to unwanted longer wavelengths while lacking sensitivity at short wavelengths, small physical area, high cost, optical cross-talk and dark rates.Here we propose a novel method to build relatively low-cost SiPM-based pixels utilising a disk of wavelength-shifting material, which overcomes some of these drawbacks by collecting light over a larger area than standard SiPMs and improving sensitivity to shorter wavelengths while reducing background. We aim to optimise the design of such pixels, integrating them into an actual 7-pixel cluster which will be inserted into a MAGIC camera and tested during real observations.Results of simulations, laboratory measurements and the current status of the cluster design and development will be presented. K: Photon detectors for UV, visible and IR photons; Scintillators, scintillation and light emission processes; Detector design and construction technologies and materials

show abstract

A new solution for mirror coating in γ-ray Cherenkov astronomy

Cited by 10 publications

References 15 publications

NUV-Sensitive Silicon Photomultiplier Technologies Developed at Fondazione Bruno Kessler

NUV-Sensitive Silicon Photomultiplier Technologies Developed at Fondazione Bruno Kessler

Singlet Oxygen Sensor Green is not a Suitable Probe for 1O2 in the Presence of Ionizing Radiation

Light-Trap: a SiPM upgrade for VHE astronomy and beyond

Contact Info

Product

Resources

About