Luminosity measurement at ATLAS - development, construction and test of scintillating fibre prototype detectors
S. Ask, P. Barillon, A. Braem, C. Cheiklali, I. Efthymiopoulos, D. Fournier, C. de La Taille, B. Di Girolamo, P. Grafstroem, C. Joram, M. Haguenauer, V. Hedberg… 展开作者
S. Ask, P. Barillon, A. Braem, C. Cheiklali, I. Efthymiopoulos, D. Fournier, C. de La Taille, B. Di Girolamo, P. Grafstroem, C. Joram, M. Haguenauer, V. Hedberg, B. Lavigne, A. Maio, A. Mapelli, U. Mjoernmark, P. Puzo, M. Rijssenbeek, J. Santos, J. G. Saraiva, H. Stenzel, M. Thioye, E. Valladolid, V. Vorobel
We are reporting about a scintillating fibre tracker which is proposed for the precise determination of the absolute luminosity of the CERN LHC at interaction point 1 where the ATLAS experiment is located. The detector needs to track protons elastically scattered under micro-rad angles in direct vicinity to the LHC beam. It is based on square shaped scintillating plastic fibres read out by multi-anode photomultiplier tubes and is housed in Roman Pots. We describe the design and construction of prototype detectors and the results of a beam test experiment at DESY. The excellent detector performance established in this test validates the detector design and supports the feasibility of the proposed challenging method of luminosity measurement.
Characterisation and calibration of a scintillating fibre detector with > 4000 multi-anode photomultiplier channels
在美因茨的Kaos光谱仪中，运行着一个高分辨率的高能粒子坐标探测器。它由直径为4000个< 1mm and is read out by >多阳极光电倍增管通道的增强纤维组成。它是世界上最先进的磁谱仪焦平面探测器之一。为了校正由不同的增益和不同的光学透射率引起的检测效率的变化，已经开发了全自动离线校准程序。该过程包括将放射性同位素源定位在探测器平面旁边以及自动采集和分析探测器信号。可以通过低程度的人工交互来校准和校准每个单独的光纤通道。
The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less readout system. The current LHCb main tracking system will be replaced by a single homogeneous detector based on scintillating fibres. This contribution gives an overview of the scintillating fibre tracker concept and presents the experience from the series production complemented by most recent test-beam and laboratory results.
We describe the Hybrid seeding, a standalone pattern recognition algorithm aiming at finding charged particle trajectories for the LHCb upgrade. A significant improvement to the charged particle reconstruction efficiency is accomplished by exploiting the knowledge of the LHCb magnetic field and the position of energy deposits in the scintillating fibre tracker detector. Moreover, we achieve a low fake rate and a small contribution to the overall timing budget of the LHCb real-time data processing.
The Muon Ionization Cooling Experiment (MICE) will demonstrate the principle of muon beam phase-space reduction via ionization cooling. Muon beam cooling will be required for the proposed Neutrino Factory or Muon Collider. The phase-space before and after the cooling cell must be measured precisely. This is achieved using two scintillating-fibre trackers, each placed in a solenoidal magnetic field. This paper describes the software reconstruction for the fibre trackers: the GEANT4 based simulation; the implementation of the geometry; digitisation; space-point reconstruction; pattern recognitio…
The light yield and the time resolution of different types of 3 m long scintillating bars instrumented with wavelength shifting fibres and read out by different models of silicon photomultipliers have been measured at a test beam at the T9 area at the CERN Proton Synchrotron. The results obtained with different configurations are presented. A time resolution better than 800 ps, constant along the bar length within 20%, and a light yield of ~ 140 (70) photoelectrons are obtained for bars 3 m long, 4.5 (5) cm wide and 2 (0.7) cm thick. These results nicely match the requirements for the Muon Det…
A prototype plastic scintillating fibre based beam profile monitor was tested at the Heidelberg Ion Therapy Centre / \textit{Heidelberg Ionenstrahl Therapiezentrum} (HIT) in 2016 to determine its beam property reconstruction performance and the feasibility of further developing an expanded system. At HIT protons, helium, carbon, and oxygen ions are available for therapy and experiments. The beam can be scanned in two dimensions using fast deflection magnets. A tracking system is used to monitor beam position and to adjust scanner currents online. A new detector system with a finer granularity …
The Beam Instrumentation group at CERN has developed a new scintillating fibre beam monitor for the measurement of secondary particle beams in the CERN Experimental Areas. The monitor has a simple design that stands out for its low material budget, vacuum compatibility, good performance, low cost, and ease of production. By using different read-out techniques the monitor can perform several functions, such as measurement of the profile, position and intensity of the beam, momentum spectrometry, generation of fast trigger signals, and measurement of the time-of-flight for particle identificatio…
We report on studies of non-toxic scintillating liquid useful for large surface detectors. Arrays of liquid scintillators offer a rather simple tool for detecting charged particles traversing a surface and tracking their path through a defined volume. Insertion of wavelength shifting fibres along the liquid scintillating containers significantly improves the light collection at the two ends of the scintillators. We have demonstrated that we can achieve timing resolution of O(1 ns) allowing good spatial resolution. Liquid scintillators with fibres read by Photo-multipliers or SiPMs provide an i…
Due to its angular dependency, Cerenkov light has long been considered a contamination signal in plastic scintillating dosimeters. In this study, we propose a novel approach designed to take advantage of this angular dependency to perform a direct measurement of an external beam radiation angle of incidence. A Cerenkov probe composed of a 10-mm long filtered sensitive volume of clear PMMA optical fibre was built. Both filtered and raw Cerenkov signals from the transport fibre were collected through a single 1-mm diameter transport fibre. An independent PSD composed of 10-mm BCF12 scintillating…
A spaghetti calorimeter (SPACAL) prototype with scintillating crystal fibres was assembled and tested with electron beams of energy from 1 to 5 GeV. The prototype comprised radiation-hard Cerium-doped Gd$_3$Al$_2$Ga$_3$O$_{12}$ (GAGG:Ce) and Y$_3$Al$_5$O$_{12}$ (YAG:Ce) embedded in a pure tungsten absorber. The energy resolution was studied as a function of the incidence angle of the beam and found to be of the order of $10\% / \sqrt{E} \oplus1\%$, in line with the LHCb Shashlik technology. The time resolution was measured with metal channel dynodes photomultipliers placed in contact with the …
The ATLAS Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment at LHC. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibers to photo-multiplier tubes (PMTs), located in the outer part of the calorimeter. The readout is segmented into about 5000 cells, each one being read out by two PMTs in parallel. To calibrate and monitor the stability and performance of the full readout chain during the data taking, …
The ATLAS Roman Pot system is designed to determine the total proton-proton cross-section as well as the luminosity at the Large Hadron Collider (LHC) by measuring elastic proton scattering at very small angles. The system is made of four Roman Pot stations, located in the LHC tunnel in a distance of about 240~m at both sides of the ATLAS interaction point. Each station is equipped with tracking detectors, inserted in Roman Pots which approach the LHC beams vertically. The tracking detectors consist of multi-layer scintillating fibre structures readout by Multi-Anode-Photo-Multipliers.
TileCal, the central hadronic calorimeter of the ATLAS detector is composed of plastic scintillators interleaved by steel plates, and wavelength shifting optical fibres. The optical properties of these components are known to suffer from natural ageing and degrade due to exposure to radiation. The calorimeter was designed for 10 years of LHC operating at the design luminosity of $10^{34}$cm$^{-2}$s$^{-1}$. Irradiation tests of scintillators and fibres have shown that their light yield decrease by about 10% for the maximum dose expected after 10 years of LHC operation. The robustness of the Til…
The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires all of its detectors to reconstruct space points in a globally consistent fashion. The beam-based alignment constants were found to be more accurate than the survey for the scintillating-fibre trackers lodged inside the bores of the superconducting magnets. This alignment algorithm can achieve unbiased measurements of the trackers rotation angles with a resolution of 6 mrad/$\sqrt{N}$ and of their position with …
TileCal is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). It is a sampling detector where scintillating tiles are embedded in steel absorber plates. The tiles are grouped forming cells, which are read-out on both sides by photomultiplier tubes (PMTs). The PMT digital samples are transmitted to the Read-Out Drivers (ROD) located in the back-end system for the events accepted by the Level 1 trigger system. The ROD is the core element of the back-end electronics and it represents the interface between the front-end electronics and the ATLAS overall Da…
This paper presents a comprehensive optimisation study to maximise the light collection efficiency of scintillating cube elements used in the SoLid detector. Very short baseline reactor experiments, like SoLid, look for active to sterile neutrino oscillation signatures in the anti-neutrino energy spectrum as a function of the distance to the core and energy. Performing a precise search requires high light yield of the scintillating elements and uniformity of the response in the detector volume. The SoLid experiment uses an innovative hybrid technology with two different scintillators: polyviny…
In July 2018 an optimization run for the proposed charm cross section measurement for SHiP was performed at the CERN SPS. A heavy, moving target instrumented with nuclear emulsion films followed by a silicon pixel tracker was installed in front of the Goliath magnet at the H4 proton beamline. Behind the magnet, scintillating-fibre, drift-tube and RPC detectors were placed. The purpose of this run was to validate the measurement's feasibility, to develop the required analysis tools and fine-tune the detector layout. In this paper, we present the track reconstruction in the pixel tracker and the…
The High Luminosity Large Hadron Collider (HL-LHC) will have a peak luminosity of $5\times10^{34} $cm$^{-2} $\,s$^{-1}$, five times higher than the design luminosity of the LHC. The hadronic ATLAS Tile Calorimeter TileCal) is a sampling calorimeter with steel as absorber and plastic scintillators as active medium. The light produced in the scintillating tiles is guided to photomultiplier tubes (PMTs), where analogue signals are produced to be shaped and conditioned before being digitized every 25\,ns. TileCal Phase-II Upgrade for the HL-LHC will allow the system can cope with the increased rad…
The ATLAS hadronic Tile Calorimeter will undergo major upgrades to the on- and off-detector electronics in preparation for the High Luminosity program of the Large Hadron Collider (HL-LHC) in 2026, so that the system can cope with the HL-LHC increased radiation levels and out-of-time pileup. The on-detector electronics of the upgraded system will continuously digitize and transmit all photo-multiplier signals to the off-detector systems at a 40 MHz rate. The off-detector electronics will store the data in pipeline buffers, produce digital hadronic tower sums for the ATLAS Level-0 trigger syste…
The basic prototype of a tile hadron calorimeter (HCAL) for the International Linear Collider (ILC) has been realised and extensively tested. A major aspect of the proposed concept is the improvement of the jet energy resolution by measuring details of the shower development and combining them with the data of the tracking system (particle flow). The prototype utilises scintillating tiles that are read out by novel Silicon Photomultipliers (SiPMs) and takes into account all design aspects that are demanded by the intended operation at the ILC. Currently, a new 12 layer prototype with about 340…
The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It is a sampling calorimeter consisting of alternating thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. Currently, an analog sum of the processed signal of several photomultipliers serves as input to the first level of trigger. Photomultiplier signals are then digitized and stored on detector and are only transferred off detector once the first trigger acceptance h…
The upcoming Mu3e experiment searches for the lepton flavour violating decay $μ^+\,\rightarrow\,e^+ e^- e^+$ with the aim of a final sensitivity of one signal decay in $10^{16}$ observed muon decays, an improvement over the preceding SINDRUM experiment by four orders of magnitude. In the first phase, the experiment will be operated at an existing intense muon beam line at the Paul Scherrer Institute. With muon stopping rates of about $10^{8}\text{s}^{-1}$, a single-event sensitivity of $2\cdot 10^{-15}$ can be achieved. For the ultimate sensitivity, a new high intensity muon beam line is requi…
欧洲核子研究中心建造了一个高强度超子束，将Sigma-输送到欧米茄设施的实验WA 89，并于1989年至1994年运行。该装置允许在超子和常规强子束配置之间快速转换。在平均动量为330 ~ 345 Gev/c的情况下，该束流提供了1.4 x 10^5/次爆发的西格玛通量，由约3 x 10^10个450 GeV/c的质子产生。在实验目标处，光束的σ/π比接近0.4，尺寸为1.6 x 3.7 cm ^2。在束流通道中用光纤描迹仪测量束粒子的轨迹和动量，在通道出口处用硅微带探测器测量束粒子的轨迹和动量。利用快速跃迁辐射探测器对光束的π分量进行了识别。
The Tile Calorimeter (TileCal) is a sampling hadronic calorimeter covering the central region of the ATLAS experiment. TileCal uses steel as absorber and plastic scintillators as active medium. The scintillators are read-out by the wavelength shifting fibres coupled to the photomultiplier tubes (PMTs). The analogue signals from the PMTs are amplified, shaped, digitized by sampling the signal every 25 ns and stored on detector until a trigger decision is received. The TileCal front-end electronics reads out the signals produced by about 10000 channels measuring energies ranging from about 30 Me…
The Mu3e experiment aims to find or exclude the lepton flavour violating decay $μ\rightarrow eee$ at branching fractions above $10^{-16}$. A first phase of the experiment using an existing beamline at the Paul Scherrer Institute (PSI) is designed to reach a single event sensitivity of $2\cdot 10^{-15}$. We present an overview of all aspects of the technical design and expected performance of the phase~I Mu3e detector. The high rate of up to $10^{8}$ muon decays per second and the low momenta of the decay electrons and positrons pose a unique set of challenges, which we tackle using an ultra th…
The Muon Ionization Cooling Experiment (MICE) collaboration seeks to demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future neutrino factory or muon collider. The emittance is measured from an ensemble of muons assembled from those that pass through the experiment. A pure muon ensemble is selected using a particle-identification system that can reject efficiently both pions and electrons. The position and momentum of each muon are measured using a high-precision scintillating-fibre tracker in a 4\,T solenoidal magnetic field. …
We propose to build and operate a detector that, for the first time, will measure the process $pp\toνX$ at the LHC and search for feebly interacting particles (FIPs) in an unexplored domain. The TI18 tunnel has been identified as a suitable site to perform these measurements due to very low machine-induced background. The detector will be off-axis with respect to the ATLAS interaction point (IP1) and, given the pseudo-rapidity range accessible, the corresponding neutrinos will mostly come from charm decays: the proposed experiment will thus make the first test of the heavy flavour production i…
