The upgrade of the Inner Tracking System (ITS), which is currently being developed by the ALICE Collaboration, aims at significantly improving the vertex and tracking resolution as well as the ...readout rate capabilities of the ALICE experiment at CERN. The new ITS detector will be installed during the second long LHC shutdown (LS2) in 2019-2020. It will comprise seven concentric layers of Monolithic Active Pixel Sensors (MAPS) with a total active surface of about 10m 2 The developed MAPS, "ALPIDE" (ALICE pixel detector), is based on the TowerJazz 180nm CMOS technology. The sensor design takes full advantage of a particular process feature, the deep p-well, which allows full CMOS circuitry within the pixel matrix, while at the same time retaining the full charge collection efficiency. A single sensor measures 15mm×30mm and contains half a million pixels distributed in 512 rows and 1024 columns. The detection efficiency of the sensors is higher than 99%, fake-hit rate is orders of magnitude lower than the required 10.6 pixel.1 event.1, and the spatial resolution is within the required 5μm over a wide range of thresholds. Sensors maintain this performance to some 10 13 1MeV n eq cm -2 (NIEL), about 10 times the expected radiation load during the detector lifetime. The behavior of the final sensor has been investigated in a series of beam measurements and proven to completely fulfill the design requirements. In this contribution, we will present the setup used for measurements with inclined tracks. This study focuses on the results from cluster shape and the sensor efficiency analysis obtained using π beams with 6 GeV/c at the Proton Synchrotron (PS) at CERN.
The planned upgrade of the A Large Ion Collider Experiment (ALICE) inner tracking system (ITS) aims at improving the ALICE performance in terms of spatial resolution and data rate readout. The new ...ITS will be a low-material-budget, high-granularity detector. It comprises seven concentric layers of monolithic active pixel sensors (MAPS), called ALPIDE, which are based on the TowerJazz 180-nm CMOS technology. In this article, we report on detection performance and radiation hardness studies of ALPIDE sensors. We show that these sensors keep having high detection efficiency for minimum ionizing particles (MIPs) (>99%) and low fake-hit rate while being radiation hard to some <inline-formula> <tex-math notation="LaTeX">{ 1.7} \times { 10}^{ 13}\,\,1 </tex-math></inline-formula> MeV <inline-formula> <tex-math notation="LaTeX">\text{n}_{\text {eq}} </tex-math></inline-formula> cm −2 of nonionizing energy loss (NIEL) and 2.7 Mrad of total ionization dose (TID), which exceeds the expected radiation load during the detector lifetime ten times. ALPIDE sensors thus completely fulfill the design requirements. In addition, we show that measured cluster shape frequencies obtained at different operating points (thresholds, bias voltages) are well described with the state-of-the-art ALICE Monte Carlo simulation.
The purpose of this study is to understand the change of the SiPM structure after irradiation. We compared the profile of the electric field in the SiPM (KETEK) active region for ten not-irradiated ...and irradiated detectors. The standard method of measurement of C-V characteristics was applied using two configurations (serial and parallel circuit) to exclude the influence of the serial resistance. Dependencies of capacitance on the frequency were studied in the range from 10 to 1000 KHz. For non-irradiated detectors we detected in CV characteristics the local instability basically connected with accumulation of charge on boundary optical isolation-silicon. In addition, the hysteresis of CV characteristics was detected. For irradiated detectors the local instability was visible as well but the hysteresis of CV characteristics was not detected. The results demonstrate that the applied method can be used for the relative analysis of how SiPM active region properties changed after irradiation.
A novel approach for designing the next generation of vertex detectors foresees to employ wafer-scale sensors that can be bent to truly cylindrical geometries after thinning them to thicknesses of ...20–40 μm. To solidify this concept, the feasibility of operating bent MAPS was demonstrated using 1.5cm×3cm ALPIDE chips. Already with their thickness of 50µm, they can be successfully bent to radii of about 2cm without any signs of mechanical or electrical damage. During a subsequent characterisation using a 5.4GeV electron beam, it was further confirmed that they preserve their full electrical functionality as well as particle detection performance.
In this article, the bending procedure and the setup used for characterisation are detailed. Furthermore, the analysis of the beam test, including the measurement of the detection efficiency as a function of beam position and local inclination angle, is discussed. The results show that the sensors maintain their excellent performance after bending to radii of 2cm, with detection efficiencies above 99.9% at typical operating conditions, paving the way towards a new class of detectors with unprecedented low material budget and ideal geometrical properties.
During the last years, semiconductor avalanche detectors are being widely used as the replacement of classical PMTs in calorimeters for many HEP experiments. In this report, basic selection criteria ...for replacement of PMTs by solid state devices and specific problems in the investigation of detectors radiation hardness are discussed. The design and performance of the hadron calorimeters developed for the future high energy nuclear physics experiments at FAIR, NICA, and CERN are discussed. The Projectile Spectator Detector (PSD) for the CBM experiment at the future FAIR facility, the Forward Calorimeter for the NA61 experiment at CERN and the Multi Purpose Detector at the future NICA facility are reviewed. Moreover, new methods of data analysis and results interpretation for radiation experiments are described. Specific problems of development of detectors control systems and possibilities of reliability improvement of multi-channel detectors systems are shortly overviewed. All experimental material is based on the investigation of SiPM and MPPC at the neutron source in NPI Rez.
The development of a dose reader for the measurement of the radiation dose from neutron and ionizing radiation is presented. The dose reader (kerma meter) is using as active element commercial PIN ...diodes with long base, which can provide a maximal dependence of the lifetime of minority carriers from the absorbed dose. We consider a simple theory of PIN diodes for the role of the kerma meter and discuss the idea for optimization of the calibration procedure. The characteristics of the dosimeter were measured for a few types of commercial diodes. The device can be useful for many practical tasks of control for radiation environments in the environment, nuclear physics and for industrial application.
Beam test results of the irradiated silicon drift detector for ALICE Kushpil, S.; Crescio, E.; Giubellino, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2006, Letnik:
566, Številka:
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Journal Article
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The Inner Tracking System (ITS) of the ALICE experiment at LHC will use high precision Silicon Drift Detectors (SDD) in two of the six cylindrical layers. In this paper we report on the results of ...beam test of a SDD irradiated with 1
GeV electrons. The aim of this test was to verify the radiation tolerance of the device under an electron fluence equivalent to twice the particle fluence expected during 10 years of ALICE operation.
The Nuclotron-based Ion Collider fAcility (NICA) is under construction at the Joint Institute for Nuclear Research (JINR), with commissioning of the facility expected in late 2022. The Multi-Purpose ...Detector (MPD) has been designed to operate at NICA and its components are currently in production. The detector is expected to be ready for data taking with the first beams from NICA. This document provides an overview of the landscape of the investigation of the QCD phase diagram in the region of maximum baryonic density, where NICA and MPD will be able to provide significant and unique input. It also provides a detailed description of the MPD set-up, including its various subsystems as well as its support and computing infrastructures. Selected performance studies for particular physics measurements at MPD are presented and discussed in the context of existing data and theoretical expectations.
Silicon Drift Detectors (SDD) equip the two intermediate layers of the Inner Tracking System (ITS) of the ALICE experiment. The SDD is required to provide a spatial precision of about 35 μm along the ...drift direction and 25 μm along the anode axis. In these detectors, the drift velocity depends on temperature (ν ∝ T -2.4 ), giving a 0.8%/K variation at room temperature. To achieve the required resolution on the drift coordinate, it is necessary to assure a temperature stability within 0.1 K. The drift velocity is determined by measuring the drift time of electrons injected in the sensor volume in fixed positions by means of dedicated MOS devices (injectors). We report the current calibration strategy, the operational experience and the injector performance during the 2010-12 data taking period. Studies of drift velocity stability as a function of time were carried out in different periods and for two different configurations of the SDD cooling system. We also show the results of a study of the time needed to stabilize the temperature after ramping up the detector high voltage. This measurement is important for the detector operation because the high voltage is ramped down and up at each LHC fill during the beam injection.
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