Effect of Crystal Structure on the Luminescence Properties of CaF2−PrF3CaF_2-PrF_3 Solid Solutions

he structure and luminescent properties of lightly doped CaF2:Pr crystals and Ca0.65Pr0.35F2.35 solid solution have been studied. The results demonstrate that the evolution of the emission spectra of the crystals with increasing PrF3 concentration can be understood in terms of the structural changes in the fluorite solid solutions, namely, the formation of defect clusters

Emission centers in Ca1–xPrxF2+x(x=0.35)Ca_{1–x}Pr_xF_{2+x} (x = 0.35) solid solutions

Luminescence spectra of Ca0.65Pr0.35F2.35 solid solutions are studied. It is found that, depending on the excitation energy, different kinds of emission centers appear in these spectra. An interconfigurational 4f 15d1 →4f2 luminescence is typical for single Pr3+ ions in tetragonal sites. Data on the structure of the solid solutions show that the emission centers involved in 1S0 → 4f2 transitions can be attributed to Pr3+ ions contained in clusters

ZnWO4 grains characterisation for GRAiNITA – a new-generation calorimeter

We will present the detection properties of ZnWO4 grains for GRAiNITA, a next-generation calorimeter based on the use of scintillator grains.With GRAiNITA, we propose the concept of a new version of the shashlik calorimeter: instead of using successive layers of scintillator and absorber we suggest to use sub millimetric (0.5-1 mm) grains of high-Z and high-density inorganic scintillator in a bath of transparent high-density liquid, as absorber. As in a conventional shashlik detector, the scintillation light is collected towards the photodetector by means of wavelength shifting fibers.In the context of high energy physics experiments, at future electron-positron colliders, this new electromagnetic calorimeter will provide extremely fine sampling and therefore the potential to considerably improve the energy resolution for photons.ZnWO4 is an excellent candidate for GRAiNITA since transparent granules of the desired size can be successfully grown with the method of spontaneous crystallization from a flux melt. While the production process is still being optimized, a small quantity of ZnWO4 granules has already been produced by the ISMA.In this communication we will discuss the study of the scintillation properties of ZnWO4 grains, in comparison to two uniform single crystals with size of 1 cm3 and 2x2x4 cm3 that have been grown using the Czochralski method, as the light yield of an inorganic crystal might depend on the particular growing process used to produce them.Furthermore, we will present the outcomes of study of the light propagation and collection in a small volume of ZnWO4 and we will describe the GRAiNITA concept

ZnWO4 grains characterisation for GRAiNITA – a new-generation calorimeter

We will present the detection properties of ZnWO4 grains for GRAiNITA, a next-generation calorimeter based on the use of scintillator grains.With GRAiNITA, we propose the concept of a new version of the shashlik calorimeter: instead of using successive layers of scintillator and absorber we suggest to use sub millimetric (0.5-1 mm) grains of high-Z and high-density inorganic scintillator in a bath of transparent high-density liquid, as absorber. As in a conventional shashlik detector, the scintillation light is collected towards the photodetector by means of wavelength shifting fibers.In the context of high energy physics experiments, at future electron-positron colliders, this new electromagnetic calorimeter will provide extremely fine sampling and therefore the potential to considerably improve the energy resolution for photons.ZnWO4 is an excellent candidate for GRAiNITA since transparent granules of the desired size can be successfully grown with the method of spontaneous crystallization from a flux melt. While the production process is still being optimized, a small quantity of ZnWO4 granules has already been produced by the ISMA.In this communication we will discuss the study of the scintillation properties of ZnWO4 grains, in comparison to two uniform single crystals with size of 1 cm3 and 2x2x4 cm3 that have been grown using the Czochralski method, as the light yield of an inorganic crystal might depend on the particular growing process used to produce them.Furthermore, we will present the outcomes of study of the light propagation and collection in a small volume of ZnWO4 and we will describe the GRAiNITA concept

The LHCb upgrade I

International audienceThe LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

The LHCb upgrade I

International audienceThe LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

The LHCb upgrade I

International audienceThe LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

The LHCb upgrade I

International audienceThe LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

The LHCb upgrade I

The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software