931 research outputs found

    Dual-readout Calorimetry with Scintillating Crystals

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    The possibility of evaluating the amount of the energy released by the electromagnetic part of a hadronic shower (f) would allow to account for one of the main sources of the fluctuation of the hadronic calorimeter response. The dual-readout method allows an event-by-event measurement of f, as it was originally demonstrated with the DREAM sampling hadronic calorimeter. This approach can be extended to homogeneous detectors like crystals if Cherenkov and scintillation light can be separated by exploiting their main properties. In this paper we present several methods developed for distinguishing the two components in PWO and BGO crystal based calorimeters and the results obtained

    Test Facility for Full-Equipped Chambers for the LHCb Muon Detector

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    The LHCb Muon System is made up by more than 1300 chambers of 20 different types, resulting in more than 120k readout channels. In order to guarantee high-quality performance during the experiment it is of crucial importance to get a complete knowledge of the fully equipped detector functionalities.A complete test system was built and a C++ ROOT software was developed to allow carring out a variety of studies on the many LHCb Muon chambers. Such system provides full control of the frontend, the high-voltage and the acquisition electronics and makes available a number of procedures to study the chambersâ performance. It was used for studies and a quality control on the chambers before and during the final positioning on the detector. In this note an overview of the hardware setup and of the software will be given. Results of measurements related to front-end channels characteristics will be presented

    Measurement system for evaluation of the muon chambers for the LHCb experiment

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    Abstract In a detector with the complexity of the LHCb, where only for the muon system more than 1300 chambers, divided into 20 different types, will be used, resulting on more than 120 k channels to be readout, it is of crucial importance to study the many types of chambers to create a complete knowledge of the detector operation and to guarantee a high-quality performance during the experiment. To make it possible, a complete setup was built and a C++ based software was developed to carry out a set of measurements on the full-equipped chambers of the LHCb muon detector. The setup is made of front-end control electronics, high-voltage supply and acquisition circuitry while the software, running on a PC, remotely controls each element of the system and implements a number of automatized procedures to assess the main characteristics of the chambers. The main advantages of this system are its versatility and speed of measurement which are crucial to the experiment since there is the need to characterize every single chamber before final installation. Moreover, in this work it was proposed to measure the starting knee of the high-voltage operational plateau without the use of an external trigger by making use of the internal structure of the chambers. Two laboratories were prepared at CERN (European Laboratory for Particle Physics) to receive this system; one used to test chambers arrived from the CERN itself and the PNPI (Petersburg Nuclear Physics Institute) production sites, and one to test the chambers arrived from the INFN (National Institute of Nuclear Physics) production sites. In this document, the hardware and software setup will be presented together with the measurement-oriented implementations

    High granularity tracker based on a Triple-GEM optically read by a CMOS-based camera

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    The detection of photons produced during the avalanche development in gas chambers has been the subject of detailed studies in the past. The great progresses achieved in last years in the performance of micro-pattern gas detectors on one side and of photo-sensors on the other provide the possibility of making high granularity and very sensitive particle trackers. In this paper, the results obtained with a triple-GEM structure read-out by a CMOS based sensor are described. The use of an He/CF4_4 (60/40) gas mixture and a detailed optimization of the electric fields made possible to obtain and very high GEM light yield. About 80 photons per primary electron were detected by the sensor resulting in a very good capability of tracking both muons from cosmic rays and electrons from natural radioactivity

    Implementation of the Control System for the LHCb Muon Detector

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    The Muon Detector of LHCb will be equipped with 1368 Multi- Wire Proportional Chambers and 24 Triple-GEM Detectors. Within the Framework of the CERN Control System Project, using PVSS as the main tool, we are developing an instrument to manage the Muon System of LHCb. Adjustment and monitoring of High and Low Voltage power supplies, on-line diagnostics and ne tuning of the Front-End read-out devices, data acquisition from the gas system and the monitoring of pressure and temperature of the experimental hall are being implemented. The system will also look after long term data archiving and alert handling. The Control System performance is currently under evaluation in a cosmic ray station. Built as a nal quality control of the LHCb Multi-Wire Proportional Chambers, allowing acquisition of data from as many as 600 Front-End readout channels, the cosmic ray station is fully managed by means of a Control System prototype

    Intraoperative β-Detecting probe for radio-guided surgery in tumour resection

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    The development of the β− based radio-guided surgery aims to extend the technique to those tumours where surgery is the only possible treatment and the assessment of the resection would most profit from the low background around the lesion, as for brain tumours. Feasibility studies on meningioma and gliomas already estimated the potentiality of this new treatment. To validate the technique, a prototype of the intraoperative probe detecting β− decays and specific phantoms simulating tumour remnant patterns embedded in healthy tissue have been realized. The response of the probe in this simulated environment is tested with dedicated procedures. This document discusses the innovative aspects of the method, the status of the developed intraoperative β− detecting probe and the results of the preclinical tests

    An Intraoperative β−\beta^- Detecting Probe For Radio-Guided Surgery in Tumour Resection

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    The development of the β−\beta^- based radio-guided surgery aims to extend the technique to those tumours where surgery is the only possible treatment and the assessment of the resection would most profit from the low background around the lesion, as for brain tumours. Feasibility studies on meningioma, glioma, and neuroendocrine tumors already estimated the potentiality of this new treatment. To validate the technique, prototypes of the intraoperative probe required by the technique to detect β−\beta^- radiation have been developed. This paper discusses the design details of the device and the tests performed in laboratory. In such tests particular care has to be taken to reproduce the surgical field conditions. The innovative technique to produce specific phantoms and the dedicated testing protocols is described in detail.Comment: 7 pages, 15 figure

    Monitoring of hadrontherapy treatments by means of charged particle detection

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    The interaction of the incoming beam radiation with the patient body in hadrontherapy treatments produces secondary charged and neutral particles, whose detection can be used for monitoring purposes and to perform an on-line check of beam particle range. In the context of ion-therapy with active scanning, charged particles are potentially attractive since they can be easily tracked with a high efficiency, in presence of a relatively low background contamination. In order to verify the possibility of exploiting this approach for in-beam monitoring in ion-therapy, and to guide the design of specific detectors, both simulations and experimental tests are being performed with ion beams impinging on simple homogeneous tissue-like targets (PMMA). From these studies, a resolution of the order of few millimeters on the single track has been proven to be sufficient to exploit charged particle tracking for monitoring purposes, preserving the precision achievable on longitudinal shape. The results obtained so far show that the measurement of charged particles can be successfully implemented in a technology capable of monitoring both the dose profile and the position of the Bragg peak inside the target and finally lead to the design of a novel profile detector. Crucial aspects to be considered are the detector positioning, to be optimized in order to maximize the available statistics, and the capability of accounting for the multiple scattering interactions undergone by the charged fragments along their exit path from the patient body. The experimental results collected up to now are also valuable for the validation of Monte Carlo simulation software tools and their implementation in Treatment Planning Software packages
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