Readout Design Research Articles

The verification of the large dynamic range readout design for the charge detector of the very large area γ-rays space telescope.

As a successor to the DArk Matter Particle Explorer (DAMPE), the Very Large Area γ-rays Space Telescope (VLAST) is being designed to strengthen γ-ray observations and extend the cosmic ray nuclei measurements up to Zr (Z = 40) and even heavier ions. Consequently, a large dynamic range is required by the charge detector of VLAST to cover the measurements of cosmic ray particles from the proton to ultra-heavy ions. To achieve the requirements, a readout design based on the three dynodes signal extracted from the photomultiplier tube has been proposed. In addition, a prototype VLAST charge detector has been developed and tested with cosmic rays, pulse UV laser, and relativistic heavy ion beams to verify this design. The test results illustrate that the dynamic range readout design can easily cover the required dynamic range of about five orders of magnitude.

Design, Calibration and Morphological Characterization of a Flexible Sensor with Adjustable Chemical Sensitivity and Possible Applications to Sports Medicine.

Active life monitoring via chemosensitive sensors could hold promise for enhancing athlete monitoring, training optimization, and performance in athletes. The present work investigates a resistive flex sensor (RFS) in the guise of a chemical sensor. Its carbon 'texture' has shown to be sensitive to CO2, O2, and RH changes; moreover, different bending conditions can modulate its sensitivity and selectivity for these gases and vapors. A three-step feasibility study is presented including: design and fabrication of the electronic read-out and control; calibration of the sensors to CO2, O2 and RH; and a morphological study of the material when interacting with the gas and vapor molecules. The 0.1 mm-1 curvature performs best among the tested configurations. It shows a linear response curve for each gas, the ranges of concentrations are adequate, and the sensitivity is good for all gases. The curvature can be modulated during data acquisition to tailor the sensitivity and selectivity for a specific gas. In particular, good results have been obtained with a curvature of 0.1 mm-1. For O2 in the range of 20-70%, the sensor has a sensitivity of 0.7 mV/%. For CO2 in the range of 4-80%, the sensitivity is 3.7 mV/%, and for RH the sensitivity is 33 mV/%. Additionally, a working principle, based on observation via scanning electron microscopy, has been proposed to explain the chemical sensing potential of this sensor. Bending seems to enlarge the cracks present in the RFS coverage; this change accounts for the altered selectivity depending on the sensor's curvature. Further studies are needed to confirm result's reliability and the correctness of the interpretation.

Performance of a triple-GEM detector with capacitive-sharing 3-coordinate (X–Y–U)-strip anode readout

The concept of capacitive-sharing readout, described in detail in a previous study, offers the possibility for the development of high-performance three-coordinates (X–Y–U)-strip readout for Micro Pattern Gaseous Detectors (MPGDs) using simple standard PCB fabrication techniques. Capacitive-sharing (X–Y–U)-strip readout allows simultaneous measurement of the Cartesian coordinates x and y of the position of the particles together with a third coordinate u along the diagonal axis in a single readout PCB. This provides a powerful tool to address multiple-hit ambiguity and enable pattern recognition capabilities in moderate particle flux environment of collider or fixed target experiments in high energy physics HEP) and nuclear physics (NP). We present in this paper the performance of a 10 cm × 10 cm triple-GEM detector with capacitive-sharing (X–Y–U)-strip anode readout. Spatial resolutions of the order of σxres = 71.6±0.8μm for X-strips, σyres = 56.2±0.9μm for Y-strips and σures =75.2±0.9μm for U-strips have been obtained at a beam test at Thomas Jefferson National Accelerator Facility (Jefferson Lab). Modifications of the readout design of future prototypes to improve the spatial resolution and challenges in scaling to large-area MPGDs are discussed.

Front-end electronics development of large-area SiPM arrays for high-precision single-photon time measurement

TRopIcal DEep-sea Neutrino Telescope (TRIDENT) plans to incorporate silicon photomultipliers (SiPMs) with superior time resolution in addition to photomultiplier tubes (PMTs) into its detection units, namely hybrid Digital Optical Modules (hDOMs), to improve its angular resolution. However, the time resolution significantly degrades for large-area SiPMs due to the large detector capacitance, posing significant challenges for the readout electronics of SiPMs in hDOM. We analyzed the influences of series and parallel connections when constructing a large-area SiPM array and designed a series-parallel connection SiPM array with differential output. We also designed a high-speed pre-amplifier based on transformers (MABA-007159) and radio frequency amplifiers (BGA2803), and an analog multi-channel summing circuit based on operational amplifiers (LMH6629). We measured the single photon time resolution (SPTR) of a 4 × 4 SiPM (Hamamatsu S13360-3050PE) array (12 × 12 mm2) of approximately 300 ps FWHM. This front-end readout design enables the large-area SiPM array to achieve high-precision single photon time measurement in one readout channel.

Arduino-Based Readout Electronics for Nuclear and Particle Physics.

Open Hardware-based microcontrollers, especially the Arduino platform, have become a comparably easy-to-use tool for rapid prototyping and implementing creative solutions. Such devices in combination with dedicated front-end electronics can offer low-cost alternatives for student projects, slow control and independently operating small-scale instrumentation. The capabilities can be extended to data taking and signal analysis at mid-level rates. Two detector realizations are presented, which cover the readouts of proportional counter tubes and of scintillators or wavelength-shifting fibers with silicon photomultipliers (SiPMs). The SiPMTrigger realizes a small-scale design for coincidence readout of SiPMs as a trigger or veto detector. It consists of a custom mixed signal front-end board featuring signal amplification, discrimination and a coincidence unit for rates of up to 200 kHz. The nCatcher transforms an Arduino Nano to a proportional counter readout with pulse shape analysis: time over threshold measurement and a 10-bit analog-to-digital converter for pulse heights. The device is suitable for low-to-medium-rate environments up to 5 kHz, where a good signal-to-noise ratio is crucial. We showcase the monitoring of thermal neutrons. For data taking and slow control, a logger board is presented that features an SD card and GSM/LoRa interface.

Design of the ASIC readout scheme for the JUNO-TAO experiment

The Taishan Antineutrino Observatory (TAO) has been proposed to precisely measure the reactor antineutrino spectrum with an energy resolution better than 2% at 1 MeV. It can provide a reference spectrum to the Jiangmen Underground Neutrino Observatory (JUNO) to enhance its sensitivity to the neutrino mass ordering measurement. In addition, TAO can also provide a benchmark to verify the nuclear database and conduct new physics searches. The TAO detector is a 2.8-ton liquid scintillator detector equipped with a 10 m2 silicon photomultiplier (SiPM) array to collect the light with a coverage of 94%. The TAO detector will be operated at -50 °C to suppress the SiPM dark count rate. In this work, we report on the design of a readout system based on the KLauS6 chip to handle the outputs from the SiPMs, which exhibits advantages of high granularity (potentially good particle identification) and large dynamic range. A dedicated mockup system has been built and its performance carefully evaluated both at room and low temperatures, measuring gain, charge linearity, signal-to-noise ratio, and dead time. The testing results show that the performance of this system can meet the requirements of TAO. However, an abnormal increase in current at 1.8 V analog power of the KLauS6 chip has been observed when operating it at temperatures below -20 °C, resulting in a potential risk on the long-term reliability. Therefore, the KLauS-based readout design is considered as an alternative option for the future upgrading of the TAO's readout system. This study also provides a reference and guidance for other relevant applications.

A diamond double-sided strip detector for alpha-tagging in associated particle imaging

- In associated particle imaging, neutrons from deuterium-tritium fusion are used to interrogate objects of interest. The associated particle imaging technique utilizes an alpha-tagging sensor in the neutron generator to detect the alpha particle that is emitted antiparallel to the neutron, providing neutron birth time and direction. This technique of neutron imaging and induced fission imaging can provide higher contrast image reconstructions and better estimations of fissile material mass than passive measurement techniques. The performance goals of an alpha-tagging sensor in associated particle imaging are a 700-ps timing resolution, a 0.5 mm spatial resolution, high level of radiation hardness, low sensitivity to X-rays, high signal-to-noise ratio, and survivability in the high temperature bake out of the neutron generator. Currently employed YAP scintillators are overwhelmed by the intense X-ray field in the neutron generator, requiring a new alpha tagging sensor design to be developed. We have developed and tested a diamond double-sided strip detector as a proposed sensor for associated particle imaging. Diamond is radiation hard, has a low sensitivity to X-rays, fast timing capabilities, high signal-to-noise ratio, and can withstand the temperatures of bake-out. The spatial resolution can be accomplished with a charge division readout and double-sided strip design. We measured the timing resolution of a single crystal chemical vapor deposition (CVD) diamond with a Cividec C6 charge amplifier readout by measuring the time-of-flight of 241Am alpha particles between a thin plastic scintillator and the diamond. We also fabricated a polycrystalline CVD diamond double-sided strip detector with charge division readout to test the spatial resolution of the design. We found that the detector met both the 700-ps timing resolution and the 0.5 mm spatial resolution goals (both reported as FWHM resolution).

Single-Ended Readout Depth-of-Interaction Measurements Based on Random Forest Algorithm

The depth-of-interaction (DOI) information can reduce parallax errors and improve the spatial resolution of positron emission tomography (PET) imaging. Current DOI detectors, with either single-ended readout design or dual-ended readout design, usually require substantial changes to the crystal arrays and/or readout electronics. In this work, we proposed a single-ended readout DOI estimation approach with minimal changes in the detector hardware design, using a supervised machine learning algorithm, random forest (RF). The energy value measured from one end of the crystal, combined with sample points of the pulse signal, were used as inputs to the DOI estimation algorithm, which provided a DOI performance close to that of the dual-ended readout design. We compared the proposed single-ended RF method with the classic dual-ended energy ratio method and a dual-ended version of the RF method, using positioning error and resolution as performance metrics for DOI estimation. All three methods achieved average absolute DOI positioning errors of < 1.00 mm and average DOI resolutions of < 2.20 mm full width at half maximum (FWHM). More specifically, we achieved the averaged DOI resolutions of 2.15, 1.80, and 1.93 mm FWHM for the single-ended RF method, dual-ended RF method, and dual-ended energy ratio method, respectively. In conclusion, the single-ended RF method achieved comparable performance without extra photodetectors and readout electronics and may provide a feasible solution for DOI estimation.

Field-programmable encoding for address-event representation.

In conventional frame-based image sensors, every pixel records brightness information and sends this information to a receiver serially in a scanning fashion. This full-frame readout approach suffers from high bandwidth requirements and increased power consumption with the increasing size of the pixel array. Event-based image sensors are gaining popularity for reducing the bandwidth and power requirements by sending only meaningful data in an event-driven approach with the help of address-event representation (AER) communication protocol. However, the event-based readout suffers from increased latency and timing error when the number of pixels with an event increase. In this paper, we introduce a new field-programmable AER (FP-AER) encoding scheme which offers benefits of both frame-based and event-based approaches. The readout design can be configured "in the field" using configuration bits. We also compare the performance of the proposed design against existing AER-based approaches for imaging applications and show that FP-AER performs best in both scanning and event-based readout.

High Impedance TES Bolometers for EDELWEISS

The EDELWEISS collaboration aims for direct detection of light dark matter using germanium cryogenic detectors with low threshold phonon sensor technologies and efficient charge readout designs. We describe here the development of Ge bolometers equipped with high impedance thermistors based on a NbxSi1−x TES alloy. High aspect ratio spiral designs allow the TES impedance to match with JFET or HEMT front-end amplifiers. We detail the behavior of the superconducting transition properties of these sensors and the detector optimization in terms of sensitivity to a-thermal phonons. We report preliminary results of a 200 g Ge detector that was calibrated using 71Ge activation by neutrons at the LSM underground laboratory.

Beam test performance of a highly granular silicon tungsten calorimeter technical prototype for the ILD

A highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) is the reference design of the ECAL for International Large Detector concept, one of the two detector concepts for the future International Linear Collider. Prototypes for this type of detector are developed within the CALICE Collaboration. The technological prototype addresses technical challenges such as integrated front-end electronics or compact layer and readout design. A stack of 7 layers was compiled and tested at DESY test beam facilities in 2017. We present preliminary results on the properties of the electromagnetic showers. An outline on the next steps is given. Finally, we illustrate the first steps of the digitization concept on simulations of the prototype.

Cold Readout Electronics for Liquid Argon TPCs in the DUNE experiment

The liquid Argon TPC (LArTPC) technology is used in DUNE, the Deep Underground Neutrino Experiment, to achieve its goals as the leading-edge international experiment for neutrino science and proton decay studies. The first 10 k-ton DUNE far detector module will employ wired-based anode planes with cold readout electronics (CE) installed inside the cryostat. The CE developed for cryogenic temperatures (77-89K) operation is an optimal solution that achieves excellent noise performance and decouples the electrode and cryostat design from the readout design. This paper reviews the experience of ProtoDUNE single-phase detector located at the CERN Neutrino Platform and provides an overview of the progress of the CE development, including recent results from system integration tests involving the characterization of new versions of the cryogenic ASICs and front-end motherboards mounted on small scale anode planes immersed in cryogenic liquids.

Design of a Quantitative Readout in a Point-of-Care Device for Cisplatin Detection

This letter presents a low-cost, lightweight, and automatic readout system for accurate quantification of cisplatin (Cis-Pt) level in a colorimetric POC device. The system relies on an RGB camera to record the color changes in the test tube and an inference function trained via machine learning techniques to estimate Cis-Pt concentration. A suitable training strategy for ensemble learning is adopted to deal with a scenario involving a small training set. In addition, the training strategy is designed to support a gray-box model, thus enabling interpretability. Experimental results show that the readout system based on the proposed strategy is able to outperform the state-of-the-art readout system for the quantification of Cis-Pt level in a colorimetric POC device.

Picosecond imaging at high spatial resolution using TOFPET2 AISC v2d and microchannel plate detector

Microchannel plate-based detectors provide advantages over their solid-state counterparts for applications where a combination of virtually zero noise photon-counting, large format, short wavelength sensitivity with high resolution timing and imaging are required. Solar-blind applications, Cherenkov detectors for high energy physics, and UV astronomy are such fields. The application to Cherenkov detection is particularly demanding, requiring time resolution below 100 picoseconds combined with imaging and high throughput. This requires the readout to combine high spatial and temporal event resolution at high rates necessitating a parallel readout approach. We describe a readout design comprising a pixellated readout array instrumented using multi-channel fast timing electronics and incorporating charge centroiding to achieve sub-pixel spatial resolution. We present experimental results of the relationship between time-over-threshold and signal amplitude and a centroiding image obtained with an MCP detector using a pixellated readout geometry. The readout was optimised for a fast electronics implementation based on the TOFPET system, a multi-channel all-in-one ASIC originally designed for time-of-flight PET using silicon photomultipliers.

Transducer Technologies for Biosensors and Their Wearable Applications.

The development of new biosensor technologies and their active use as wearable devices have offered mobility and flexibility to conventional western medicine and personal fitness tracking. In the development of biosensors, transducers stand out as the main elements converting the signals sourced from a biological event into a detectable output. Combined with the suitable bio-receptors and the miniaturization of readout electronics, the functionality and design of the transducers play a key role in the construction of wearable devices for personal health control. Ever-growing research and industrial interest in new transducer technologies for point-of-care (POC) and wearable bio-detection have gained tremendous acceleration by the pandemic-induced digital health transformation. In this article, we provide a comprehensive review of transducers for biosensors and their wearable applications that empower users for the active tracking of biomarkers and personal health parameters.

Development and Characterization of Modular Readout Design for Two-Panel Head-and-Neck Dedicated PET System Based on CZT Detectors.

Cadmium zinc telluride (CZT) detectors are suitable for various applications due to the good energy resolution and the simple pixilation to achieve high spatial resolution. Our group is developing a two-panel head and neck dedicated positron emission tomography system based on CZT detectors. Each panel will consist of 150 CZT crystals (4×4×0.5 cm3) covering an area of 20×15 cm2 in an edge-on configuration to achieve high detector efficiency at 511 keV. In this work, we present the design and development of a full data acquisition chain that enables a low noise and compact readout for each panel. The initial results of the readout circuit were quantified using a 1 kHz square wave test pulse. The pulse amplitude was chosen to generate approximately the same amount of charges as a 511 keV photon would provide in CZT. The best-case FWHM electronic noise at 511 keV was measured to be 0.69% ± 0.16% (3.52 ± 0.81 in keV units after conversion). The FWHM electronic noise at 511 keV for a complete DAQ chain was 4.33% ± 0.30% (22.13 ± 1.53 in keV units).

Luminance-Depth Reconstruction From Compressed Time-of-Flight Histograms

Single photon avalanche diodes (SPADs) combined with high-frequency time-to-digital converters (TDCs) enable the estimation of photon Time-of-Flight (ToF) for active 3D-depth imaging. Nevertheless, SPAD sensors still face hardware limitations due to a complex pixel readout design and a large amount of data collected by way of pixel-wise histograms. The intrinsic high background illumination (BI) also remains a challenging issue for the related depth reconstruction algorithms. Using a physically-relevant SPAD sensor model, this work tackles these issues by implementing a pixel-wise ToF histogram compressive sensing (CS) with a specific deep generative model based reconstruction. It demonstrates a possible reduction of hardware design constraints while reaching a depth inference root mean square error below 16 centimeters regardless of BI (50–1050 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathrm{W}\mathrm{/}{\mathrm{2}}^{2}$</tex-math></inline-formula> ) and distance (20 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathrm{m}$</tex-math></inline-formula> ), at a compression ratio (CR) of 10% (32 CS measurements). In addition, this paper introduces a novel multimodal reconstruction from SPAD data, enabling joint depth and luminance estimations. Indeed, since ToF histogram raw data gathers multiple physical scene characteristics, we propose a two-part deep generative model (DGM) capable of inferring Super-Resolved depth maps and normalized luminance images, independently from the average scene BI. Our key contributions related to the DGM topology design are the introduction of proper normalization layers with a learned pile-up effect compensation, multidimensional-multiscale filtering and the concatenation of Softmax-ReLU activation functions to capture both peak-position and relative amplitude features. Numerically, depth and luminance maps reconstructions of natural scenes respectively reach more than 30 dB and 25 dB PSNRs for any CR higher than 2.5%.

Low-Cost Portable Readout System Design for Inductively Coupled Resonant Sensors

Spiral coil-based inductor–capacitor ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> ) resonant sensors have seen many applications in agriculture, healthcare, biomanufacturing, and consumer electronics. Traditional techniques to interrogate such sensors using vector network analyzers (VNAs) are expensive and often not portable, whereas custom readouts suffer from high cost, low range of usable interrogation distances, or low frequency range. This article proposes a new simple, low-cost, and portable readout design based on the technique of coherent demodulation. A complete theoretical analysis examining how the interrogation distance is related to other circuit parameters is presented. Finally, a complete readout system was implemented using printed circuit board technology and commercially available off-the-shelf components. The system operates between 1 and 100 MHz and the fabricated system consumes 1.26 W. Measurements show that the system operates reliably and repeatably with interrogation distances up to 5 cm.

Design, Fabrication, and Characterization of a Micro Coriolis Mass Flow Sensor Driven by PZT Thin Film Actuators

A micro Coriolis flow sensor accurately measures small mass flows without being affected by properties of the fluid. This paper presents a micro Coriolis mass flow sensor driven by PZT thin film piezoelectric actuators, which allows a combination of large actuation force, low power dissipation and virtually no self-heating. The sensor was fabricated using surface channel technology, resulting in a tube diameter of 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> and a thin silicon-rich silicon nitride tube wall of 1.2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> thick, with a few additional steps to form the integrated piezoelectric actuators. The integrated actuators can actuate the sensor into both swing mode and twist mode. Both actuation modes were evaluated for different fluids and the results are presented in this paper. In the case of swing mode actuation, an optical readout was used to detect the resulting Coriolis movement, resulting in a relatively low sensitivity. In the case of twist mode actuation, a capacitive readout was used and, in comparison to previously published devices, a high mass flow sensitivity was achieved thanks to an optimized readout design. The measurement results show the read-out noise has a standard deviation of 0.15% of the full scale of 1.8 gh <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> when actuated in the twist mode. [2020-0392]

Development of detector pixels based on silicon photomultipliers for the Cherenkov gamma-ray telescope TAIGA-IACT

The design and scheme of signal readout from silicon photomultipliers OnSemi MicroFJ-60035 used as sensitive elements (pixels) of a new detector cluster for the camera of the Cherenkov gamma-ray telescope TAIGA-IACT are developed. The design of the developed pixel follows the shape of the photomultiplier tube XP1911 using in the first generation clusters, and that provides compatibility of the new cluster with the telescope camera. Due to the adjustable gain, the developed scheme allows one to detect and digitize signals in a wide dynamic range from several to 10 000 photons.