Fluid systems for RICH detectors Ullaland, O.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2005, Letnik:
553, Številka:
1
Journal Article
Recenzirano
The optical properties of the radiator media are of prime importance in Ring Imaging Cherenkov detectors. The main requirements for the radiator fluid are a stable refractive index and a photon ...absorption as low as possible. We will in this note cover some of the cleaning procedures which are required together with distillation and similar separation procedures. Thin film membranes have been introduced during the last decade. They have proven particularly interesting in separating air from some Cherenkov fluids. We will also discuss the use of molecular sieves.
Performance of the LHCb RICH detector at the LHC Adinolfi, M.; Aglieri Rinella, G.; Albrecht, E. ...
The European physical journal. C, Particles and fields,
05/2013, Letnik:
73, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This ...provides charged particle identification over a wide momentum range, from 2–100 GeV/
c
. The operation and control, software, and online monitoring of the RICH system are described. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types (
π
, K, p) is achieved.
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.
VUV absorbing vapours in n-perfluorocarbons Albrecht, E.; Baum, G.; Bellunato, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2003, Letnik:
510, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The optical transparency of perfluorocarbons used as Cherenkov media is of prime importance to many Ring Imaging Cherenkov detectors. We will in this paper show that the main photon absorbers in ...these fluids are hydrocarbons with double or triple bonds. We will moreover discuss a process which can eliminate these pollutants and restore the intrinsic excellent optical transparency of these fluids in the VUV range.
Glass-coated beryllium mirrors for the LHCb RICH1 detector Barber, G.J.; Brook, N.H.; Cameron, W. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2007, Letnik:
570, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The design, manufacture and testing of lightweight glass-coated beryllium spherical converging mirrors for the RICH1 detector of the LHCb experiment are described. The mirrors need to be lightweight ...to minimize the material budget and fluorocarbon-compatible to avoid degradation in the RICH1 C
4F
10 gas radiator. Results of the optical measurements for small-sized prototypes and for a full-sized prototype mirror are reported.
The DIRAC spectrometer installed at CERN PS was upgraded in order to study simultaneously A2π and AπK atoms, namely the bound states of two π mesons, and of π and K mesons, respectively. The detector ...system can now accept a high intensity beam of 2–6×1011 primary protons per second. The electronics and the data-acquisition system can handle a very large amount of data to identify π, K, p, e and µ, allowing the selection of ππ and πK pairs in the offline analysis. The resolution of the longitudinal and transverse components of the relative momentum Q of each meson pair in their center-of-mass system with respect to the direction of the pair was substantially improved. The analysis of their distributions allowed an reliable separation between the meson pairs originating from hadronic atoms and the backgrounds permitting the measurement of the lifetimes of hadronic atoms in the ground state and π–π, π–K s-wave scattering lengths. The upgraded setup also allowed the study of the long-lived excited states of ππ atoms.
Quenching the scintillation in CF4 Cherenkov gas radiator Blake, T.; D׳Ambrosio, C.; Easo, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2015, Letnik:
791
Journal Article
Recenzirano
Odprti dostop
CF4 is used as a Cherenkov gas radiator in one of the Ring Imaging Cherenkov detectors at the LHCb experiment at the CERN Large Hadron Collider. CF4 is well known to have a high scintillation photon ...yield in the near and far VUV, UV and in the visible wavelength range. A large flux of scintillation photons in our photon detection acceptance between 200 and 800nm could compromise the particle identification efficiency. We will show that this scintillation photon emission system can be effectively quenched, consistent with radiationless transitions, with no significant impact on the photons resulting from Cherenkov radiation.
Operation, optimisation, and performance of the DELPHI RICH detectors Albrecht, E.; van Apeldoorn, G.; Augustinus, A. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
1999, Letnik:
433, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
The Ring Imaging Cherenkov detectors of DELPHI represent a large-scale particle identification system which covers almost the full angular acceptance of DELPHI. The combination of liquid and gas ...radiators (C
4F
10, C
5F
12, and C
6F
14) provides particle identification over the whole secondary particle momentum spectrum at LEP I and LEP II. Continuing optimisation on the hardware as well as on the online and offline software level have resulted in a stable operation of the complete detector system for more than five years at full physics performance.
Thin Gap Gas Chambers were proposed for a possible upgrade of the end-caps of the DELPHI detector at LEP. Two full prototypes were built and tested at the CERN 20GeV/c SPS pion beam. The main ...construction parameters of the detector and the on-board front-end electronics characteristics are reviewed. Test beam results from the full prototypes, showing the general feasibility of the detector, will be presented.
Thin Gap Gas Chambers have been proposed for an upgrade of the end-caps of the DELPHI detector at LEP due to their very limited longitudinal size combined with high efficiency and high granularity. ...Two full prototypes of the detector have been built and tested. We report on the on-board processor for coordinate computation and data transmission.
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