Optical systems for future Ring Imaging Cherenkov detectors Cardinale, R.; Petrolini, A.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
October 2023, 2023-10-00, Letnik:
1055
Journal Article
Recenzirano
Optical systems for Ring Imaging Cherenkov (RICH) detectors have historically taken a variety of designs. Nowadays, technological developments allow more flexibility in the design and construction ...than was possible in the past, such as lightweight secondary mirrors that can be placed in the acceptance of an experiment, widespread use of non-spherical optical surfaces, flexible and fast tools for parametric optimisation of the optical systems before feeding into a full detector simulation. Within this context, the design of the LHCb RICH optical system for the current Run-3 data-taking of the LHC will be presented and compared to the parametric design of the proposed optics for the Upgrade II for the future HL-LHC phase.
Future detection of extensive air showers (EAS) produced by ultra high energy cosmic particles by means of space-based fluorescence telescopes will open a new window on the universe and allow cosmic ...ray and neutrino astronomy at a level that is virtually impossible for ground based detectors. In the context of the extreme universe space observatory (EUSO) project, an end-to-end simulation of EAS observation with a spatial detector has been designed (EUSO simulation and analysis framework, ESAF). This paper describes the detailed Monte-Carlo developed to simulate all the physical processes involved in the fluorescence detection technique, from the EAS development to the instrument response. Particular emphasis is given to modeling the light propagation in the atmosphere and the effect of clouds. The simulation is used to assess the performances of EAS spatial detection. Main results on energy threshold and resolution, direction resolution and
X
max determination are reported. Results are based on EUSO telescope design, but are also extended to larger and more sensitive detectors.
► We review the relevant issues for the detection of extensive air showers from space. ► We define the requirements for a suitable telescope orbiting around the Earth. ► We estimate the expected ...performances in ideal conditions. ► The design of a space-based telescope is a very challenging task. ► It is very important to optimize its performances and set safe design margins.
We review the main issues that are relevant for the observation of extensive air showers from an Earth-orbiting satellite. Extensive air showers are produced by the interaction of ultra-high energy cosmic particles with the atmosphere and can be observed by an orbiting telescope detecting the air scintillation light.
We provide the main analytical formulas and semi-analytical results needed to optimize the design of a suitable telescope and estimate the best-expected performance and the minimal necessary requirements for the observation.
While we have in mind an EUSO-like general-purpose experiment, the results presented in this paper are useful for any kind of space-based experiment.
The housing of the photo-detectors for future Ring Imaging Cherenkov detectors is a complex task, regardless of the sensor choice, due to the many requirements. The sensor housing for LHCb Upgrade II ...will be an evolution of the one developed for Upgrade I where a totally modular solution, based on fully autonomous functional units called Elementary Cells has been adopted. The main challenge of the new Elementary Cell will be to include active cooling. With SiPM, cooling well below zero degrees centigrade is required. Two different cooling strategies are considered and the status of the design for the Upgrade II Elementary Cell is presented.
Abstract
Background
Cardiac allograft vasculopathy (CAV) is still the main drawback of heart transplantation (HTx) and percutaneous coronary intervention (PCI) is a palliative measure because of the ...high incidence of PCI failure. The bioresorbable scaffolds (BRS) could represent a potential novel therapeutic tool for the treatment of coronary obstructions in CAV.
Purpose
To investigates the effects of BRS implantation in CAV patients in a Nationwide prospective study.
Methods
Multicentre, single-arm, prospective, open-label study that included patients affected by advanced CAV treated with PCI and second-generation ABSORB BRS. The primary endpoint was the incidence of 12-month angiographic in-segment scaffold restenosis (ISSR). Secondary endpoints were the composite of cardiac death, myocardial infarction, and target lesion revascularisation at 12-and 36-month follow-up and the incidence of ISSR at 36 months. A paired analysis of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) at baseline and follow-up was also performed.
Results
Between 2015–2017 35 HTx patients were enrolled and treated on 44 coronary lesions with 51 BRS. The primary endpoint occurred in 13.5% of the lesions (5/37), with a cumulative ISSR rate up to 3 years of 16.2% (6/37).Angiographic lumen loss was 0.40±0.62mm at 12 months and 0.53±0.57mm at 36 months. Overall survival was 91.4% and 74.3%, and MACEs 14.2% and 31.4% at 12 and 36 months, respectively. At the paired intracoronary imaging analysis a significant increase of the vessel external elastic membrane area in the treated segment of the BRS was described at the OCT, while some progression of CAV was detected proximally at the IVUS assessment.
Conclusions
BRS in CAV was feasible and safe, with an ISSR incidence similar to drug-eluting stents. For the first time, a positive remodeling was observed in HTx patients after PCI. Vessel enlargement and the lack of metallic stents may allow repeated PCI avoiding the vessel shrinkage caused by the addition of multiple metal layers, being CAV a complex clinical scenario with a high incidence of MACEs, mainly driven by PCI failure.
Funding Acknowledgement
Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Partial funding by Abbott Vascular Italy
The limitations in performance of the present RICH system in the LHCb experiment are given by the natural chromatic dispersion of the gaseous Cherenkov radiator, the aberrations of the optical system ...and the pixel size of the photon detectors. Moreover, the overall PID performance can be affected by high detector occupancy as the pattern recognition becomes more difficult with high particle multiplicities. This paper shows a way to improve performance by systematically addressing each of the previously mentioned limitations. These ideas are applied in the present and future upgrade phases of the LHCb experiment. Although applied to specific circumstances, they are used as a paradigm on what is achievable in the development and realisation of high precision RICH detectors.
A modular power supply system is described, for use in the Ring Imaging Cherenkov Detectors of the LHCb experiment. The main characteristics of the supply are very good time stability and voltage ...resolution, full programmability, floating supplies, self protection and remote control. The choice of a commercial HV module with standard control inputs allows easy customisation to adapt our design to different requirements. The realisation shown here supplies voltages up to 20
kV with a maximum current of 0.5
mA and up to 32 channels on a single crate.
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