Straw Tracker Research Articles

The Mu2e Digitizer ReAdout Controller (DiRAC): Characterization and radiation hardness

The Mu2e experiment at Fermilab will search for the neutrino-less coherent conversion of a muon into an electron in the field of a nucleus. Mu2e detectors comprise a straw tracker, an electromagnetic calorimeter and a veto for cosmic rays. The calorimeter employs 1348 Cesium Iodide crystals readout by silicon photo-multipliers and fast front-end, and digitization electronics. The digitization board is named DiRAC (Digitizer ReAdout Controller) and 140 cards are needed for the readout of the full calorimeter. The DiRACs are hosted in crates located on the external surface of calorimeter disks, inside the detector solenoid cryostat and must sustain very high radiation and magnetic field so it was necessary to fully qualify it. Several version of prototypes were validated for operation in a high-vacuum (10−4 Torr) and under a 1T magnetic field. An extensive radiation hardness qualification campaign, carried out with photons, 14 MeV neutron beams, and 200 MeV protons, certified the DiRAC design to sustain doses up to 12 krad, neutron fluences up to ∼10111MeV neq/cm2, and very low occurrences of single-event effects. The qualification campaigns and quality assurance procedures will be reviewed.

Production tests of front-end electronics for Straw Tube Trackers in HADES and PANDA experiments at FAIR

PASTTREC is an 8-channel readout Application-Specific Integrated Circuit (ASIC) designed for the Straw Tracking System (STS) in the HADES experiment and for the Straw Tube Tracker (STT) and the Forward Tracker (FT) detectors in the PANDA experiment, both at the FAIR facility. Since more than 5000 ASICs were produced for both experiments, efficient qualification tests are required. For this purpose, the multi-chip test setup and dedicated verification procedures were developed. In this paper, the measurement results for the first batch of 140 Front-End Boards (FEBs), each hosting two ASICs, are presented. Since a significant number (280) of PASTTREC chips were tested, obtained statistical distributions of key parameters are also reported. The estimated yield (97%) and the process-related spread of the chip parameters are discussed.

Design and qualification of the Mu2e electromagnetic calorimeter electronic system

The Mu2e experiment (Bernstein et al., 0000) [1] at Fermilab will search for the neutrino-less coherent conversion of a muon into an electron in the field of a nucleus. Mu2e detectors comprise a straw tracker, an electromagnetic calorimeter and a veto for cosmic rays. The calorimeter employs 1348 Cesium Iodide crystals readout by silicon photomultipliers and fast front-end and digitization electronics. The front-end electronics consists of two discrete readout circuits (AMP-HV) for each crystal. These provide the amplification and shaping stage,linear regulation of the SiPM bias voltage and monitoring. The SiPM and front-end control electronics is implemented in a battery of mezzanine boards each equipped with an ARM processor that controls a group of 20 Amp-HV circuits, distributes the low voltage and the high-voltage reference values, sets and reads back the locally regulated voltages. The electronic is hosted in crates located on the external surface of calorimeter disks. The crates also host the waveform digitizer board (DIRAC) that performs digitization of the front end signals and transmit the digitized data to the Mu2e DAQ. Calorimeter electronic is hosted inside the cryostat and it must substain very high radiation and magnetic field so it was necessary to fully qualify it. The constraints on the calorimeter front-end and readout electronics, the design technological choices and the qualification tests will be reviewed.

Vacuum-Compatible, Ultra-Thin-Wall Straw Tracker; Detector construction, Thinner straw R&D, and the brand-new graphite-straw development

The COMET experiment at J-PARC aims to search for a lepton-flavour violating process of muon to electron conversion in a muonic atom, μ-e conversion, with a branching-ratio sensitivity better than 10−16, 4 orders of magnitude better than the present limit, in order to explore the parameter region predicted by most well-motivated theoretical models beyond the Standard Model. The need for such an excellent sensitivity places several stringent requirements on the detector; (i) good momentum resolution, <2%, for 100 MeV/c electron, which is primarily limited by multiple scattering effect for this momentum region; and (ii) high rate capability, up to 5×109μ−/s muon beam enabled by J-PARC. In order to fulfil such requirements a vacuum-compatible, ultra-thin-wall straw tracker has been designed, and a 20μm-thick Mylar straw with 70 nm Al cathode has been developed employing an ultrasonic-welding technique. The detector performances such as detection efficiency and intrinsic spatial resolutions were investigated with test-beam experiments and confirmed to be acceptable for the COMET experiment. The construction of the straw tracker for COMET Phase-I has been completed.In parallel to the construction of present tracker a thinner 12μm-thick straw has been developed with joint collaboration among KEK, JINR and CERN. During this R&D, it was noticed that the current technology cannot achieve tubes much smaller than 5 mm in diameter or walls much thinner than 12μm. We also launched a brand-new project to realize the graphite-textile straw which has a potential to realize an extremely low material tracker.In this article, a brief report on detector construction with a present 20μm-thick straw, R&D on a new 12μm-thick straw, and a brand-new graphite straw, is provided.

The straw tracking detector for the Fermilab Muon g-2 Experiment

The Muon g-2 Experiment at Fermilab uses a gaseous straw tracking detector to make detailed measurements of the stored muon beam profile, which are essential for the experiment to achieve its uncertainty goals. Positrons from muon decays spiral inward and pass through the tracking detector before striking an electromagnetic calorimeter. The tracking detector is therefore located inside the vacuum chamber in a region where the magnetic field is large and non-uniform. As such, the tracking detector must have a low leak rate to maintain a high-quality vacuum, must be non-magnetic so as not to perturb the magnetic field and, to minimize energy loss, must have a low radiation length. The performance of the tracking detector has met or surpassed the design requirements, with adequate electronic noise levels, an average straw hit resolution of (110 ± 20) μm, a detection efficiency of 97% or higher, and no performance degradation or signs of aging. The tracking detector's measurements result in an otherwise unachievable understanding of the muon's beam motion, particularly at early times in the experiment's measurement period when there are a significantly greater number of muons decaying. This is vital to the statistical power of the experiment, as well as facilitating the precise extraction of several systematic corrections and uncertainties. This paper describes the design, construction, testing, commissioning, and performance of the tracking detector.

Straw Chambers for the NA64 Experiment

The aim of this work is to describe the characteristics and properties of the particle-tracking detectors created at the Joint Institute for Nuclear Research by the glued straw tube technology for the NA64 experiment on the extracted electron beam of the CERN SPS. The physical task of the experiment is to search for phenomena of the dark sector and dark matter.

Construction on vacuum-compatible straw tracker for COMET Phase-I

The COMET experiment at J-PARC aims to search for a lepton-flavour violating process of muon to electron conversion in a muonic atom, μ-e conversion, with a branching-ratio sensitivity of better than 10−16, 4 orders of magnitude better than the present limit, in order to explore the parameter region predicted by most of well-motivated theoretical models beyond the Standard Model. The need for such an excellent sensitivity places several stringent requirements on the detector; (i) good momentum resolution, <2%, for 100 MeV/c electron, which is primarily limited by multiple scattering effect for this momentum region, and (ii) high rate capability, up to 5×109μ−/s muon beam by J-PARC. In order fulfil such requirements, we decided to develop the straw-base planar tracker which is operational in vacuum and made of an extremely light material. The COMET straw tracker consists of 10 mm diameter straw tube, longer than 1 m length, with 20μm-thick Mylar foil and 70 nm-thick aluminium cathode.Recently, two big milestones, detector-performance verification by the full-scale prototype with 100 MeV/c electron beam, and start the assembly of final straw tracker for COMET Phase-I, were achieved. In this article, details of these two big milestones are provided. In addition, some prospects on the straw tracker development towards the COMET Phase-II are also given.

Protection of the in-vacuum-operating straw chambers from vacuum penetration

Abstract In the past years, drift chambers with thin-wall tubes (straws) operating in high vacuum ( ∼ 10−5 mb) has become to be used in experimental studies of rare decays. Any drift tube of the operating chamber may suffer a mechanical or electrical damage and a subsequent leak. The complete failure of the tube is not excluded either. To protect the chambers against the above damage, we have developed and tested a relatively simple protection system based on uniquely designed energy-independent devices. If air-tightness is broken and gas starts leaking from the tube into the vacuum, they automatically cut off the gas flow on both ends of the damaged tube and disconnect it from the gas supply.

Design and performance evaluation of front-end electronics for COMET straw tracker

Abstract The COMET experiment at J-PARC aims to search for the charged lepton flavor violating process of neutrinoless muon-to-electron conversion with an improvement of a sensitivity by a factor of 10000 to the current limit. We plan to use a straw tube tracker with high momentum resolution as an electron detector . To read out the signal from the tracker precisely, optimal front-end electronics is needed, and we have developed the readout electronics board called ROESTI, which contains all the front-end processes; preamplification, pulse shaping, discrimination, and digitization. All the functionalities are controlled by FPGA. Using the prototype, we have constructed the calibration method and evaluated the fundamental performance. In this paper, we report the details of the design and performance for the ROESTI prototype.

The Muon g − 2 experiment at Fermilab

The Muon g−2 experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 ppb, reducing the experimental uncertainty by a factor of 4 compared to the previous measurement at BNL (E821). The measurement technique adopts the storage ring concept used for E821, with magic-momentum muons stored in a highly uniform 1.45 T magnetic dipole field. The spin precession frequency is extracted from an analysis of the modulation of the rate of higher-energy positrons from muon decays, detected by 24 calorimeters and 3 straw tracking detectors. Compared to the E821 experiment, muon beam preparation, storage ring internal hardware, field measuring equipment, and detector and electronics systems are all new or significantly upgraded. Herein, I report on the status of the experiment as of Sept. 2016, presenting the magnetic field uniformity results after the completion of the first round of shimming and outlining the construction progress of the main detector systems.

Detecting and quantifying ambiguity: a neural network approach

It is not, in general, possible to have access to all variables that determine the behavior of a system. Having identified a number of variables whose values can be accessed, there may still be hidden variables which influence the dynamics of the system. The result is model ambiguity in the sense that, for the same (or very similar) input values, different objective outputs should have been obtained. In addition, the degree of ambiguity may vary widely across the whole range of input values. Thus, to evaluate the accuracy of a model it is of utmost importance to create a method to obtain the degree of reliability of each output result. In this paper we present such a scheme composed of two coupled artificial neural networks: the first one being responsible for outputting the predicted value, whereas the other evaluates the reliability of the output, which is learned from the error values of the first one. As an illustration, the scheme is applied to a model for tracking slopes in a straw chamber and to a credit scoring model.

A new system of STRAW chambers operating in vacuum for the NA62 experiment

Large 2.15 × 2.15 m2 area straw tube chambers have been developed to meet the specific requirements of the NA62 experiment. The main goal of the NA62 experiment at the CERN SPS is to measure the branching ratio of the ultra-rare decay with 10% accuracy. This can be achieved by detecting about 100 Standard Model events with 10% background in 2 - 3 years of data taking. A low mass tracking system is necessary to achieve a high resolution on kinematic quantities while timing resolution is mandatory to match the outgoing pion with the incoming kaon. Design, construction and first performance are reported.

The Muon g-2 Experiment Overview and Status as of June 2016

The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion, which is a factor of four improvement over the previous E821 measurement at Brookhaven. The experiment will also extend the search for the electric dipole moment (EDM) of the muon by approximately two orders of magnitude, with a sensitivity down to 10-21 e.cm. Both of these measurements are made by combining a precise measurement of the 1.45T storage ring magnetic field with an analysis of the modulation of the decay rate of higher-energy positrons (from anti-muons), recorded by 24 calorimeters and 3 straw tracking detectors. The recent progress in the alignment of the electrostatic quadrapole plates and the trolley rails inside the vacuum chambers, and in establishing the uniform storage ring magnetic field will be described.

Development of an extremely thin-wall straw tracker operational in vacuum – The COMET straw tracker system

The COMET experiment at J-PARC aims to search for a lepton-flavour violating process of muon to electron conversion in a muonic atom, μ-e conversion, with a branching-ratio sensitivity of better than 10−16, 4 orders of magnitude better than the present limit, in order to explore the parameter region predicted by most of well-motivated theoretical models beyond the Standard Model. The need for this sensitivity places several stringent requirements on the detector development. The experiment requires to detect the monochromatic electron of 105MeV, the momentum resolution is primarily limited by the multiple scattering effect for this momentum region. Thus we need the very light material detector in order to achieve an excellent momentum resolution, better than 2%, for 100MeV region. In order to fulfil such a requirement, the thin-wall straw-tube planar tracker has been developed by an extremely light material which is operational in vacuum. The COMET straw tracker consists of 9.8mm diameter straw tube, longer than 1m length, with 20-μm-thick Mylar foil and 70-nm-thick aluminium deposition. Currently even thinner and smaller, 12μm thick and 5mm diameter, straw is under development by the ultrasonic welding technique.

An X-ray mapper for the Mu2e experiment

We report on the construction and performance of a scanner using a collimated x-ray beam to find the positions of wires, straws, slots and spheres. The technique is based on measuring the transmission rate of the beam, and their positions can be determined ~25μm accuracy. The spheres or slots attached to the detector can also be optically surveyed externally to transfer the coordinates of wires and straws to other detector systems. The scanner was developed for the Mu2e straw tracker but may have a wide range of applications.

Compressed baryonic matter at FAIR: JINR participation

The scientific mission of the Compressed Baryonic Matter(CBM) experiment is the study of the nuclear matter properties at the high baryon densities in heavy ion collisions at the Facility of Antiproton and Ion Research (FAIR) in Darmstadt. We present the results on JINR participation in the CBM experiment. JINR teams are responsible on the design, the coordination of superconducting(SC) magnet manufacture, its testing and installation in CBM cave. Together with Silicon Tracker System it will provide the momentum resolution better 1[Formula: see text] for different configuration of CBM setup. The characteristics and technical aspects of the magnet are discussed. JINR plays also a significant role in the manufacture of two straw tracker station for the muon detection system. JINR team takes part in the development of new method for simulation, processing and analysis experimental data for different basic detectors of CBM.

Performance evaluation of multiple (32 channels) sub-nanosecond TDC implemented in low-cost FPGA

NA62 experiment Straw tracker frontend board serves as a gas-tight detector cover and integrates two CARIOCA chips, a low cost FPGA (Cyclon III, Altera) and a set of 400Mbit/s links to the backend. The FPGA houses 16 pairs of sub-nanosecond resolution TDCs with derandomizers and an output link serializer. Evaluation methods, including simulations, and performance results of the system in the lab and on a detector prototype are presented.

E08-008: Exclusive study of deuteron electrodisintegration near threshold

The study of threshold electrodisintegration of and elastic scattering on the only stable two nucleon system, the deuteron, can reveal specific aspects of the N-N interaction. The simplicity of electrodisintegration along with the simplicity of the deuteron makes this study most appropriate for revealing these interactions. By using an incident beam of polarized electrons and by measuring the polarization of the recoiling proton, the ratio of the electric (GE) and magnetic (GM) form factors for \(d\left( {\vec e,e'\vec p} \right)\) (and \(p\left( {\vec e,e'\vec p} \right)\)) reactions may be extracted. This experiment was conducted in Hall A at Jefferson Lab in Newport News, Virginia using a beam of polarized electrons provided by the CEBAF Accelerator incident on a liquid deuterium (and hydrogen) target. The scattered electron and the recoiling (polarized) proton were detected using the High Resolution Spectrometers of Hall A. To determine the polarization of the recoil proton, an analyzing material was placed perpendicular to the protons trajectory through the spectrometer, in front of a set of straw chambers. Due to the spin-orbit interactions involved in the scattering of the proton from the analyzer material, asymmetries seen in the distribution of events detected by these straw chambers reveal the polarization of the recoil proton. By tracking the spin procession of the polarized protons from the straw chambers back to the target, the transferred and induced polarization of the proton may be determined. The (double-spin) asymmetries observed in the straw chambers will first be studied for the well-known elastic \(p\left( {\vec e,e'\vec p} \right)\) process and compared to the asymmetries for \(d\left( {\vec e,e'\vec p} \right)n\left( {x_B = 1} \right)\). The analysis will then be repeated to determine how these asymmetries change with increasing xB (to the kinematic limit for deuteron electrodisintegration).

Tracking with Straw Tubes in the PANDA Experiment

The PANDA spectrometer will be built at the FAIR facility at Darmstadt (Ger- many) to perform accurate tests of the strong interaction through ¯ pp andannihilation studies. The charged particle tracking at PANDA will be done using both solid state and gaseous detectors. Among the latter, two straw tube detector systems will be built (1). The cylindrical, central straw tube tracker features a high spatial and momentum resolu- tion for a wide range of particle momenta from about 8 GeV/c down to a few 100 MeV/c, together with particle identification in the momentum region below about 1 GeV/c by measuring the specific energy-loss. A new technique, based on self-supporting straw double layers with intrinsic wire tension developed for the COSY-TOF straw tracker (2), has been adopted for the PANDA trackers. The development of the readout electronics for the straw tubes is ongoing. Prototypes have been produced and used to instrument straw tube modules that have been tested with cosmic rays and proton beams. Design issues of the PANDA straw tubes, together with the results of the prototype tests are presented. The PANDA experiment (3) is one of four experiments planned for the future Facility for Antiproton and Ion Research (FAIR) (4) in Darmstadt, Germany. The scientific program of the PANDA Collaboration is oriented towards precise studies of strong interaction in the QCD transi- tion region between asymptotically free quarks and hadronic matter. The maximum available center of mass total energy in the PANDA experiment ( √ s= 5.46 GeV/c 2 ) will allow hadronic structures involving the charm quark degrees of freedom to be investigated. The PANDA detector will be in- stalled around the internal target of the High Energy Storage Ring (HESR), which will accumulate, accelerate and cool up to 10 11 antiprotons. In the experiment, the annihilation of antiprotons with

Production tools to manufacture straw chambers used in multipurpose detector for NICA-MPD project

We describe a new approach in the production of technological devices to manufacture high-precision holes in the ring elements of submodules of the Straw EC Tracker with a precision position relative to each other and the assembly table for pasting the ring frame elements of the submodules with thin-film drift tubes according to the strict requirements for their diameters.