Electron Test Beam Research Articles

Status and R & D of ASHIPH-SiPM option for PID

The ASHIPH (Aerogel, SHifter, PHotomultiplier) Cherenkov counters are considered as a particle identification system alternative option for the detector on future Super Charm-Tau factory. The ASHIPH counters have been operating successfully in the KEDR and SND experiments in Novosibirsk at the Budker Institute of Nuclear Physics. Previously in our experiments Micro Channel Plate PMTs were used for the photon detection in the ASHIPH counters. Now, we have developed a prototype of the ASHIPH counter with SiPM (Silicon PMTs) array as a photodetector. Such an upgrade will increase the number of detected photoelectrons by 2.5 times and consequently improve the quality of particle separation. The results of testing the ASHIPH counter prototype on the electron test beam facility of the VEPP-4M accelerator is presented.

Commissioning of Pixel Sensor Telescope for Monolithic Active Pixel Sensor Characterization

The Monolithic Active Pixel Sensors (MAPS) have been promisingly demonstrated as a core part of tracking detectors used in many experiments. In order to obtain decent particle tracks generated after high-energy particle collision, it is especially important that the detector must consist of high-performance MAPS. A pixel sensor telescope is a tool employed to investigate the properties of MAPS using high-energy particle test beams. At the Synchrotron Light Research Institute (SLRI), the pixel sensor telescope assembled with five layers of 50-µm thick pixel sensors has been commissioned and tested both in the laboratory with a radioactive source and by a high-energy electron test beam produced at the SLRI Beam Test Facility. With sensor signal threshold ranging from 9.73 to 10.15 DAC and noises between 0.62 and 0.87 DAC, each plane of the pixel sensor telescope can detect particles decaying from the radioactive source. Moreover, the test beam profiles have been measured to be 4.00 - 4.56 mm and 1.15 - 2.29 mm in horizontal and vertical axes, respectively. Correlations between each plane have been observed and confirm the proper operation of the pixel sensor telescope. Consequently, the pixel sensor telescope can be used to characterize the pixel sensor prototype.

Double-hit separation and dE/dx resolution of a time projection chamber with GEM readout

A time projection chamber (TPC) with micropattern gaseous detector (MPGD) readout is investigated as main tracking device of the International Large Detector (ILD) concept at the planned International Linear Collider (ILC). A prototype TPC equipped with a triple gas electron multiplier (GEM) readout has been built and operated in an electron test beam. The TPC was placed in a 1 T solenoidal field at the DESY II Test Beam Facility, which provides an electron beam up to 6 GeV/c. The performance of the readout modules, in particular the spatial point resolution, is determined and compared to earlier tests. New studies are presented with first results on the separation of close-by tracks and the capability of the system to measure the specific energy loss dE/dx. This is complemented by a simulation study on the optimization of the readout granularity to improve particle identification by dE/dx.

Ethernet Embedded Readout Interface for Timepix2—Katherine readout for Timepix2

This paper introduces a readout system for the Timepix2. Firstly, this chip is described and the readout modes are discussed in detail. The new readout system presented is based on the Gigabit Ethernet interface and implements pre-processing, i.e. decoding of the raw pixel data, directly in the hardware. The device suppresses zero pixels, so that only useful data are sent to the computer/server. In a special independent mode, the readout can send completed data files to a remote server via SSH and does not need to use a control software. In island mode, the device stores measured data to a local storage (SD card). The process of calibration and its results are also discussed. An energy resolution of approximately 1.5 keV was achieved for 60 keV gamma-rays from an 241Am source. We present enhanced features of the readout system facilitating measurements and data evaluation, such as the HW support of clustering and Matrix Occupation Control. The former implements the pixel clustering directly in the hardware and sends energy calibrated results of the cluster finding algorithm to the computer. The latter automatically controls acquisition time of detector in order to reduce cluster overlapping. Measurements with Timepix2 are presented in iron and electron test beams. Results show that pixels of Timepix2 saturate at a per-pixel energy deposition of 1.9 MeV.

Feasibility study of neutron production at SLRI beam test facility

SLRI Beam Test Facility (SLRI-BTF) has been constructed in order to increase usage of the Siam Photo Source injector. SLRI-BTF aims to provide electron test beams for calibration and testing of high-energy particle detectors and diagnostic instrumentations. The test-beam energy varies from 40 MeV to 1.2 GeV with adjustable intensity from a few to several millions of electrons per repetition rate. Since the test-beam energy is sufficiently large, the electron test beam can be used to produce photoneutrons resulted from collision of high-energy electrons to metal targets. Similar to the electron test beams, this neutron source will be utilized for calibration and testing of neutron detectors and instrumentations. In this work, the neutron production and its angular dependence has been investigated using the PHITS simulation code. The results show that photoneutrons generated by collision of the high-energy electron beam on a tungsten target are in range of intermediate and fast neutrons or 0.01 - 10 MeV with peak contribution at 0.6 ± 0.1 MeV and uniformly distributed in angular direction. For the primary beam of 108 electrons per spill at SLRI-BTF, the photoneutron flux is predicted to be around 50 neutrons/cm2. Based on this study, the possibility to service a neutron source for users in the future will be determined further.

Performance and Moli\xe8re radius measurements using a compact prototype of LumiCal in an electron test beam

A new design of a detector plane of sub-millimetre thickness for an electromagnetic sampling calorimeter is presented. It is intended to be used in the luminometers LumiCal and BeamCal in future linear e^{+}e^{-} collider experiments. The detector planes were produced utilising novel connectivity scheme technologies. They were installed in a compact prototype of the calorimeter and tested at DESY with an electron beam of energy 1–5 GeV. The performance of a prototype of a compact LumiCal comprising eight detector planes was studied. The effective Molière radius at 5 GeV was determined to be (8.1 ± 0.1 (stat) ± 0.3 (syst)) mm, a value well reproduced by the Monte Carlo (MC) simulation (8.4 ± 0.1) mm. The dependence of the effective Molière radius on the electron energy in the range 1–5 GeV was also studied. Good agreement was obtained between data and MC simulation.

Development of the SLRI beam test facility for characterization of monolithic active pixel sensors

Abstract Synchrotron Light Research Institute (SLRI) has successfully constructed a new experimental station, a Beam Test Facility (BTF), to the current SLRI accelerator complex. SLRI-BTF is capable of producing electron test beams with the number of electrons ranging from a few to millions of electrons per spill and with tunable energy from 40 MeV up to 1.2 GeV. The required intensity and energy of the test beam are obtained using a combination of a metal target to reduce high-intensity primary beam and a synchrotron booster to accelerate secondary beam to desired energy. The repetition rate of the test beam is up to 0.5 Hz depending on the selected energy and the pulse width is 90 ns. SLRI-BTF targets to service electron test beams with defined intensity and energy for testing and calibration of high-energy particle detectors as well as other beam diagnostic instrumentations. In commissioning, a pixel sensor telescope was employed as a detector to measure the number of electrons and as a preparation to investigate efficiency of mono active pixel sensors. The results confirm production of the low multiplicity of high-energy electrons at SLRI-BTF and the efficiency of a test pixel sensor is successfully calculated.

Efficiency and timing performance of the MuPix7 high-voltage monolithic active pixel sensor

The MuPix7 is a prototype high voltage monolithic active pixel sensor with 103×80μm2 pixels thinned to 64 μm and incorporating the complete read-out circuitry including a 1.25 Gbit/s differential data link. Using data taken at the DESY electron test beam, we demonstrate an efficiency of 99.3 % and a time resolution of 14 ns. The efficiency and time resolution are studied with sub-pixel resolution and reproduced in simulations.

Beam test characterization of CMS silicon pixel detectors for the phase-1 upgrade

The Silicon Pixel Detector forms the innermost part of the CMS tracking system and is critical to track and vertex reconstruction. Being in close proximity to the beam interaction point, it is exposed to the highest radiation levels in the silicon tracker. In order to preserve the tracking performance with the LHC luminosity increase which is foreseen for the next years, the CMS collaboration has decided to build a new pixel detector with four barrel layers mounted around a reduced diameter beam pipe, as compared to the present three layer pixel detector in the central region. A new digital version of the front-end readout chip has been designed and tested; it has increased data buffering and readout link speed to maintain high efficiency at increasing occupancy. In addition, it offers lower charge thresholds that will improve the tracking efficiency and position resolution. Single chip modules have been evaluated in the DESY electron test beam in terms of charge collection, noise, tracking efficiency and position resolution before and after irradiation with 24GeV protons from the CERN Proton Synchroton equivalent to the fluence expected after 500fb−1 of integrated luminosity in the fourth layer of the pixel tracker. High efficiency and an excellent position resolution have been observed which are well maintained even after the proton irradiation. The results are well described by the CMS pixel detector simulation.

Focusing Aerogel RICH for particle identification and momentum measurement

The work is devoted to the development of the Focusing Aerogel RICH (FARICH). The option of the forward RICH for the SuperB project in Italy is presented. It features an aerogel-NaF radiator and MCP photodetectors. Monte Carlo simulation predicts the π / K separation at the level better than 3 σ from 0.2 to 7 GeV/ c, the μ / π separation—from 0.13 to 1.3 GeV/ c, and the kaon momentum measurement with an accuracy of about 1% at 1 GeV/ c. FARICH for the Super Charm-Tau Factory project in Novosibirsk is proposed. Monte Carlo simulation predicts μ / π separation at the level better than 3 σ for a momentum from 0.3 to 1.7 GeV/ c. A prototype will be tested on the new electron test beam facility at VEPP-4M collider.

Energy-zcorrelation measurements of electron bunches

Bunch length and energy-$z$ correlation measurements were performed on the high energy (28.5 GeV) electron test beam of the A-line and End Station A (ESA) facilities at the SLAC National Accelerator Laboratory. The longitudinal profile of each bunch was measured by imaging the synchrotron light emitted as the electrons traversed a highly dispersive bend after being streaked by a transverse rf deflecting cavity. In addition, high frequency diodes and pyroelectric detectors placed at a ceramic gap in the beam line were used to measure the length of the bunch in ESA.

A large TPC prototype for a linear collider detector

A Time Projection Chamber (TPC), operated in a detector at a future linear e +e − collider, will require a significantly advanced readout concept compared to the traditional pad-wire-based systems used previously. The LCTPC collaboration studies the prospects of TPC readout systems based on Micro-Pattern Gas Detectors, namely GEMs and Micromegas, in combination with pads or a CMOS on the underlying anode plane. In small TPC prototype chambers, resolutions of better than σ ⊥ = 100 μ m were demonstrated for drift distances of up to 66 cm. In the future, the R&D efforts will focus on the technical realization of large-surface readout systems with the aim to develop a technical concept for a readout module of a future TPC. A large TPC prototype with a diameter of 77 cm has been constructed for the planned studies. It is part of a test beam infrastructure at the electron test beam at DESY. First test beam operations with Micromegas and GEM based prototype modules in December 2008 and during 2009 gave promising results.

Construction and Performance of a High Granularity Calorimeter

We describe the realization and performance of a prototype high granularity calorimeter built with lead and scintillating fibers. We describe the calorimeter construction and show cosmic ray and electron test beam results obtained with a custom-designed trigger.

Studies of the CMS electromagnetic calorimeter performance in the electron test beam

The Compact Muon Solenoid (CMS) is a general purpose detector for LHC. The electromagnetic calorimeter (ECAL), comprising about 76,000 PbWO4 scintillating crystals, will allow a very accurate energy measurement of electrons and photons. The 36 supermodules (units of 1700 crystals) of the barrel have been successfully integrated inside the CMS solenoid. In 2006 nine supermodules with the final mechanics, cooling and electronics were exposed to electron test beams in order to perform precise inter-calibration and comprehensive studies of the detector response. A survey of results from these tests are here presented, with emphasis given to the energy resolution and linearity achieved.

The MINERvA neutrino scattering experiment

This has been a very active time for the MINERvA experiment. It has received construction approval and funding and is on track for installation in the NuMI beam in 2009. Much R&D work has been completed. This poster presents an update on the results from the recent R&D and prototyping work, the full experiment construction, and preparations for hadron and electron test beam calibrations of the detector components. The poster also describes the main physics goals and expected event rates for the experiment.

Signal-to-noise measurements on irradiated CMS tracker detector modules in an electron testbeam

The CMS experiment at the Large Hadron Collider at CERN is in the last phase of its construction. The harsh radiation environment at LHC will put strong demands in radiation hardness to the innermost parts of the detector. To assess the performance of irradiated silicon microstrip detector modules, a testbeam was conducted at the Testbeam 22 facility of the DESY research center. The primary objective was the signal-to-noise measurement of fully irradiated CMS Tracker modules to ensure their functionality up to 10 years of LHC operation. The paper briefly summarises the basic setup at the facility and the hardware and software used to collect and analyse the data. Some interesting subsidiary results are shown, which confirm the expected behaviour of the detector with respect to the signal-to-noise performance over the active detector area and for different electron energies. The main focus of the paper are the results of the signal-to-noise over reverse bias voltage measurements for CMS Tracker Modules which were exposed to different radiation doses.

CMS electromagnetic calorimeter performance and test beam results

Energy resolution of the CMS crystal electromagnetic calorimeter has been measured with an electron test beam using a fully equipped barrel supermodule. Both intrinsic energy resolution and energy resolution for electrons with quasi-uniform impact on the crystal surface are measured. The amplitude of the signal collected from crystals is reconstructed by a digital filtering technique and corrections for the position dependent response are applied in the case of quasi-uniform impact. The resolution measured for the supermodule is fully compatible with design expectations.

Energy linearity and resolution of the ATLAS electromagnetic barrel calorimeter in an electron test-beam

A module of the ATLAS electromagnetic barrel liquid argon calorimeter was exposed to the CERN electron test-beam at the H8 beam line upgraded for precision momentum measurement. The available energies of the electron beam ranged from 10 to 245 GeV. The electron beam impinged at one point corresponding to a pseudo-rapidity of η = 0.687 and an azimuthal angle of φ = 0.28 in the ATLAS coordinate system. A detailed study of several effects biasing the electron energy measurement allowed an energy reconstruction procedure to be developed that ensures a good linearity and a good resolution. Use is made of detailed Monte Carlo simulations based on GEANT4 which describe the longitudinal and transverse shower profiles as well as the energy distributions. For electron energies between 15 and 180 GeV the deviation of the measured incident electron energy over the beam energy is within 0.1%. The systematic uncertainty of the measurement is about 0.1% at low energies and negligible at high energies. The energy resolution is found to be about 10% · E for the sampling term and about 0.2% for the local constant term.

Performance of a DEPFET prototype module for the ILC vertex detector

For the detection of secondary vertices of long lived bottom and charm quarks at the proposed International Linear Collider (ILC) a DEPFET pixel detector is one of the favored technology options. DEPFET pixel sensors, in which the amplifying transistor structure is contained in the pixel cell itself on a fully depleted bulk, are unique devices in terms of their large signal and low noise capability and their obtainable spatial resolution with very thin detectors. DEPFET pixel prototype modules with close to ILC specifications have been tested in the laboratory and, for the first time, in a 6 GeV electron test beam. The different noise sources have been calculated and compared with the measured value of ENC/spl ap/225 e/sup -/ for the entire readout chain.

CMS ECAL PERFORMANCE - TESTBEAM RESULTS

The Compact Muon Solenoid (CMS) experiment is a general-purpose detector designed to explore the physics of proton-proton collisions at a centre-of-mass energy of 14 TeV over the full range of luminosities expected at the Large Hadron Collider (LHC). The Electromagnetic Calorimeter (ECAL) will play an essential role in the study of the electroweak symmetry breaking, particularly through the exploration of the Higgs boson sector. To evaluate its characteristics, an ECAL prototype was placed in an electron testbeam at CERN. Highlights of results obtained during the test beam campaign are presented.