| 1. |
- Aartsen, M. G., et al.
(författare)
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Very high-energy gamma-ray follow-up program using neutrino triggers from IceCube
- 2016
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e. g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015.
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| 2. |
- Correa, J., et al.
(författare)
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On the Charge Collection Efficiency of the PERCIVAL Detector
- 2016
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Ingår i: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- The PERCIVAL soft X-ray imager is being developed by DESY, RAL, Elettra, DLS, and PAL to address the challenges at high brilliance Light Sources such as new-generation Synchrotrons and Free Electron Lasers. Typical requirements for detector systems at these sources are high frame rates, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency, and (multi)-mega-pixel arrangements. PERCIVAL is a monolithic active pixel sensor, based on CMOS technology. It is designed for the soft X-ray regime and, therefore, it is post-processed in order to achieve high quantum efficiency in its primary energy range (250 eV to 1 keV) . This work will report on the latest experimental results on charge collection efficiency obtained for multiple back-side-illuminated test sensors during two campaigns, at the P04 beam-line at PETRA III, and the CiPo beam-line at Elettra, spanning most of the primary energy range as well as testing the performance for photon-energies below 250 eV . In addition, XPS surface analysis was used to cross-check the obtained results.
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| 3. |
- Khromova, A., et al.
(författare)
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Report on recent results of the PERCIVAL soft X-ray imager
- 2016
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Ingår i: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:November
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Tidskriftsartikel (refereegranskat)abstract
- The PERCIVAL (Pixelated Energy Resolving CMOS Imager, Versatile And Large) soft X-ray 2D imaging detector is based on stitched, wafer-scale sensors possessing a thick epi-layer, which together with back-thinning and back-side illumination yields elevated quantum efficiency in the photon energy range of 125–1000 eV. Main application fields of PERCIVAL are foreseen in photon science with FELs and synchrotron radiation. This requires high dynamic range up to 105 ph @ 250 eV paired with single photon sensitivity with high confidence at moderate frame rates in the range of 10–120 Hz. These figures imply the availability of dynamic gain switching on a pixel-by-pixel basis and a highly parallel, low noise analog and digital readout, which has been realized in the PERCIVAL sensor layout. Different aspects of the detector performance have been assessed using prototype sensors with different pixel and ADC types. This work will report on the recent test results performed on the newest chip prototypes with the improved pixel and ADC architecture. For the target frame rates in the 10–120 Hz range an average noise floor of 14e− has been determined, indicating the ability of detecting single photons with energies above 250 eV. Owing to the successfully implemented adaptive 3-stage multiple-gain switching, the integrated charge level exceeds 4 centerdot 106 e− or 57000 X-ray photons at 250 eV per frame at 120 Hz. For all gains the noise level remains below the Poisson limit also in high-flux conditions. Additionally, a short overview over the updates on an oncoming 2 Mpixel (P2M) detector system (expected at the end of 2016) will be reported.
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