Cms Ecal Daq Monitoring System Cucciati, Giacomo
EPJ Web of Conferences,
01/2019, Letnik:
214
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The Large Hadron Collider (LHC) at CERN in Geneva, Switzerland, has just completed the Run 2 era, colliding protons at a center-of-mass energy of 13 TeV at high instantaneous luminosity. The Compact ...Muon Solenoid (CMS) is a general-purpose particle detector experiment at the LHC. The CMS electromagnetic calorimeter (ECAL) has been designed to achieve excellent energy and position resolution for electrons and photons. A multi-machine distributed software configures the on-detector and off-detector electronic boards composing the ECAL data acquisition (DAQ) system and follows the life cycle of the acquisition process. Since the beginning of Run 2 in 2015, many improvements to the ECAL DAQ have been implemented to reduce and mitigate occasional errors in the front-end electronics and not only. Efforts at the software level have been made to introduce automatic recovery in case of errors. Automatic actions has made even more important the online monitoring of the DAQ boards status. For this purpose a new web application, EcalView, has been developed. It runs on a light Node.js JavaScript server framework. It is composed of several routines that cyclically collect the status of the electronics. It display the information when web requests are launched by client side graphical interfaces. For each board, detailed information can be loaded and presented in specific pages if requested by the expert. Server side routines store information regarding electronics errors in a SQLite database in order to perform offline analysis about the long term status of the boards.
The extensive use of scintillating crystals in medical imaging field is generating a growing interest in Monte Carlo simulation of light transportation and photon collection inside inorganic ...materials. The critical parameters under study which affect the performance of medical devices are the number of photons collected per unit of energy deposited (light yield), the energy resolution, the effect of dimensions and surface state and the time profiles of the scintillation process. Moreover, most of the crystals used in Positron Emission Tomography (PET) applications, such as lutetium orthosilicate (LSO), are anisotropic, potentially influencing the performances. In particular the recent development of time of flight PET scanners requires a detailed knowledge of timing profiles of the crystals in terms of time of arrival of single photons, scintillation rise and decay times. Furthermore the effort towards innovative endoscopic probe for PET examination requires an extensive analysis of the effect of the dimensions of small crystals on the parameters mentioned. Different simulation tools are employed nowadays for detailed studies of interaction of particles in inorganic materials and tracing of the scintillating photons produced. In particular our attention is focused on SLitrani and Geant4. SLitrani is a general purpose Monte-Carlo program simulating light propagation, developed for high energy experiments, in particular in the frame of the CMS experiment at LHC. Its most advanced characteristics is the ability to handle anisotropic materials, thus retaining a quite general application. Geant4 is a general purpose Monte Carlo toolkit widely used in high energy physics, astroparticle physics and nuclear physics, which includes an optical physics process category to simulate the production and propagation of light. In the frame of the Crystal Clear Collaboration, we have been developing and testing innovative scintillation technologies for medical applications, and with this respect Monte Carlo techniques are powerful tools for investigating the performances of our setups. In order to validate and accurately describe the inorganic crystals developed we have been comparing the performances of the SLitrani and Geant4 frameworks, and started a preliminary comparison with experimental results obtained in our laboratories.
The EndoTOFPET-US collaboration develops a novel multimodal device for Ultrasound (US) Endoscopy and Positron Emission Tomography (PET) for detecting and quantifying novel morphologic and functional ...biomarkers for pancreas and prostate oncology. The detector is based on scintillating crystals with Silicon Photomultiplier (SiPM) read-out, aiming at a time of flight coincidence time resolution of 200 ps and a spatial resolution of ≈ 1 mm to allow for more sensitive, more precise and lower radiation-dose imaging than whole-body devices. We develop a framework, which is built around the Geant4-based simulation toolkit GAMOS, to simulate and reconstruct realistic imaging scenarios with this asymmetric PET detector. Both attenuation and activity DICOM data from e.g. PET/CT scans can be incorporated as phantoms in the simulations. The framework takes care of distributing jobs on a computing grid which is crucial for running large-scale simulations on voxelised phantoms. A set of studies on simple simulated phantoms quantifies the influence of acquisition time and detector movement on the spatial image resolution and overall image quality. A scan time of approx. 10 min and small rotation of around 10° yields a sufficient image quality. We further present qualitative studies of the expected performance of the EndoTOFPET-US detector using voxelised patient PET/CT DICOM datasets. The studies suggest that the endoscopic approach is able to separate the prostatic lesion well from the background radiation from prostate and bladder.
Compelling experimental evidences of neutrino oscillations and their implication that neutrinos are massive particles have given neutrinoless double beta decay a central role in astroparticle ...physics. In fact, the discovery of this elusive decay would be a major breakthrough, unveiling that neutrino and antineutrino are the same particle and that the lepton number is not conserved. It would also impact our efforts to establish the absolute neutrino mass scale and, ultimately, understand elementary particle interaction unification. All current experimental programs to search for neutrinoless double beta decay are facing with the technical and financial challenge of increasing the experimental mass while maintaining incredibly low levels of spurious background. The new concept described in this paper could be the answer which combines all the features of an ideal experiment: energy resolution, low cost mass scalability, isotope choice flexibility and many powerful handles to make the background negligible. The proposed technology is based on the use of arrays of silicon detectors cooled to 120 K to optimize the collection of the scintillation light emitted by ultra-pure crystals. It is shown that with a 54 kg array of natural CaMoO4 scintillation detectors of this type it is possible to yield a competitive sensitivity on the half-life of the neutrinoless double beta decay of 100Mo as high as ~10E24 years in only one year of data taking. The same array made of 40CaMoO4 scintillation detectors (to get rid of the continuous background coming from the two neutrino double beta decay of 48Ca) will instead be capable of achieving the remarkable sensitivity of ~10E25 years on the half-life of 100Mo neutrinoless double beta decay in only one year of measurement.
PDF
