Readout System Research Articles

Analog pile-up circuit technique using a single capacitor for the readout of Skipper-CCD detectors

With Skipper-CCD detectors it is possible to take multiple samples of the charge packet collected on each pixel. After averaging the samples, the noise can be extremely reduced allowing the exact counting of electrons per pixel. In this work we present an analog circuit that, with a minimum number of components, applies a double slope integration (DSI) and at the same time averages the multiple samples, producing at its output the pixel value with sub-electron noise. For this purpose, we introduce the technique of using the DSI integrator capacitor to add the skipper samples. An experimental verification using discrete components is presented, together with an analysis of its noise sources and limitations. After averaging 400 samples it was possible to reach a readout noise of 0.18 e- rms/pix, comparable to other available readout systems. Due to its simplicity and significant reduction of the sampling requirements, this circuit technique is of particular interest in particle experiments and cameras with a high density of Skipper-CCDs.

A Dual Module Parallel Readout System Based on 10 Gb TCP/IP Transmission for HEPS-BPIX Detector

A hybrid pixel detector, which will be used in the high energy photon source (HEPS) with Beijing PIXel (BPIX) chips, has been successfully developed to the third-generation HEPS-BPIX3. It is a 2-D imaging detector with pixel size of 150 <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> . The BPIX can work at 20 MHz without dead-time, but the frame rate can only reach 200 Hz limited by the 1-Gb/s TCP protocol of the third-generation readout system. The time structure of HEPS makes it possible to study the ultrafast dynamic evolution of crystal structure, even room-temperature data collection of macromolecular crystallography, so the detector needs to have the ability of fast readout to increase the frame rate up to 1 kHz. Based on this, fast readout and transmission bandwidth become crucial issues, meanwhile, the cost of electronics also should be considered. Therefore, a new dual modules readout board (DMRB) based on field programmable gate array (FPGA) was proposed to realize the imaging of 1.5 Mpixels detector without delay at the frame rate of 1.2 kHz, and an innovative 10 Gb TCP/IP firmware was developed to improve bandwidth. This article introduces how to design, implement, and run the whole system in detail from the perspective of DMRB hardware and firmware, and finally gives the performance results of DMRB with through silicon via (TSV) module at 1.2 kHz frame rate.

Research on weak signal readout systems for neutrinoless double-beta decay experiments based on bolometers

This paper develops a prototype signal readout system based on the physical mechanism and signal-to-noise ratio of the ultralow voltage signal characteristics of a bolometer. The preamplifier module is one of the key difficulties of the prototype: the internal resistance is as high as one hundred MΩ, the signal frequency band is susceptible to low-frequency noise, and the high energy resolution requires a high signal-to-noise ratio that is matching the input impedance to design a preamplifier with a good common-mode rejection ratio and low inherent noise. Therefore, the preamplifier circuit is designed with an instrument amplifier. At present, the energy resolution of the bolometer is 500 ~ 1000 nV (root mean square, rms) at the input of the signal readout system. According to the calculation, the theoretical value of the inherent noise at the input end is 394 nVrms, including a theoretical value for the equivalent input voltage noise of 166 nVrms, while the actual measurement value is less than 180 nVrms, which is basically consistent with the theoretical value. In addition, the signal gain (10,000) and frequency response of the prototype are experimentally verified. The experimental results show that the gain is 9400, and the frequency and waveform are not distorted within the allowable error range; all of these parameters meet the design requirement.

Performance of the ReD TPC, a novel double-phase LAr detector with silicon photomultiplier readout

A double-phase argon Time Projection Chamber (TPC), with an active mass of 185 g, has been designed and constructed for the Recoil Directionality (ReD) experiment. The aim of the ReD project is to investigate the directional sensitivity of argon-based TPCs via columnar recombination to nuclear recoils in the energy range of interest (20–200,hbox {keV}_{nr}) for direct dark matter searches. The key novel feature of the ReD TPC is a readout system based on cryogenic Silicon Photomultipliers (SiPMs), which are employed and operated continuously for the first time in an argon TPC. Over the course of 6 months, the ReD TPC was commissioned and characterised under various operating conditions using gamma -ray and neutron sources, demonstrating remarkable stability of the optical sensors and reproducibility of the results. The scintillation gain and ionisation amplification of the TPC were measured to be g_1 = (0.194 pm 0.013) photoelectrons/photon and g_2 = (20.0 pm 0.9) photoelectrons/electron, respectively. The ratio of the ionisation to scintillation signals (S2/S1), instrumental for the positive identification of a candidate directional signal induced by WIMPs, has been investigated for both nuclear and electron recoils. At a drift field of 183 V/cm, an S2/S1 dispersion of 12% was measured for nuclear recoils of approximately 60–90,hbox {keV}_{nr}, as compared to 18% for electron recoils depositing 60 keV of energy. The detector performance reported here meets the requirements needed to achieve the principal scientific goals of the ReD experiment in the search for a directional effect due to columnar recombination. A phenomenological parameterisation of the recombination probability in LAr is presented and employed for modeling the dependence of scintillation quenching and charge yield on the drift field for electron recoils between 50–500 keV and fields up to 1000 V/cm.

Sensitive and Rapid Detection of Citrus Scab Using an RPA-CRISPR/Cas12a System Combined with a Lateral Flow Assay.

Citrus is the most extensively produced fruit tree crop in the world and is grown in over 130 countries. Fungal diseases in citrus can cause significant losses in yield and quality. An accurate diagnosis is critical for determining the best management practices and preventing future losses. In this study, a Recombinase polymerase amplification (RPA)-clustered regularly interspaced short palindromic repeats (CRISPR)/associated (Cas) system was established with the integration of a lateral flow assay (LFA) readout system for diagnosis of citrus scab. This detection can be completed within 1 h, is highly sensitive and prevents cross-reactions with other common fungal citrus diseases. Furthermore, the detection system is compatible with crude DNA extracted from infected plant tissue. This RPA-CRISPR/Cas12a-LFA system provides a sensitive, rapid, and cost-effective method with promising and significant practical value for point-of-care diagnosis of citrus scab. To our knowledge, this is the first report to establish an RPA- and CRISPR-based method with LFA for fungal diseases in plants.

Rational Design of All Resistive Multifunctional Sensors with Stimulus Discriminability

AbstractA rational approach is proposed to design soft multifunctional sensors capable of detection and discrimination of different physical stimuli. Herein, a flexible multifunctional sensor concurrently detecting and distinguishing minute temperature and pressure stimuli in real time is developed using electrospun carbon nanofiber (CNF) films as the sole sensing material and electrical resistance as the only output signal. The stimuli sensitivity and discriminability are coordinated by tailoring the atomic‐ and device‐level structures of CNF films to deliver outstanding pressure and temperature sensitivities of −0.96 kPa−1 and −2.44% °C−1, respectively, enabling mutually exclusive sensing performance without signal cross‐interference. The CNF multifunctional sensor is considered the first of its kind to accomplish the stimulus discriminability using only the electrical resistance as the output signal, which is most convenient to monitor and process for device applications. As such, it has distinct advantages over other reported sensors in its simple, cost‐effective fabrication and readout system. It also possesses other invaluable traits, including good bending stability, fast response time, and long‐term durability. Importantly, the ability to simultaneously detect and decouple temperature and pressure stimuli is demonstrated through novel applications as a skin‐mountable device and a flexible game controller.

A hybrid optical strategy based on graphene quantum dots and gold nanoparticles for selective determination of gentamicin in the milk and egg samples

A rapid and sensitive hybrid nanosensor was reported with a colorimetric and fluorometric readout system using graphene quantum dots (GQDs) and gold nanoparticles (AuNPs) for the detection of gentamicin (GENTA) in milk and egg samples. In the presence of AuNPs, the fluorescence (FL) intensity of GQDs gradually decreased due to the inner filter effect (IFE) of AuNPs on the FL intensity of GQDs. In addition of GENTA into AuNPs, AuNPs get aggregated and changed their color from red to blue, due to which the IFE of AuNPs reduced and hence, enhanced FL intensity of GQDs with varying concentration of GENTA from 1.03 to 16.55 μM with a lower detection limit of 0.422 μM and 0.493 μM in colorimetric and fluorimetric systems, respectively. The practical application of the developed nanosensor is tested against the real spiked sample. The excellent and straightforward recovery efficiency of the developed nanosensor for the determination of GENTA and can be used as a promising and adaptable tool for speedy monitoring of food quantity.

A new technique to establish the uniformity of the induction gap in GEM based detectors

This work explores the use of multichannel readout electronics, already in use for quality assurance in gain uniformity studies, to measure the uniformity of the induction gap in Gas Electron Multipliers (GEM) based detectors. The devised procedure also provides a qualification of the readout electrodes in terms of disconnected or shorted channels. The measurement is based on inducing a signal on the readout strips by pulsing the bottom layer of the GEM foil, and measuring the amplitude of the induced signal. In this work, signals are readout using the analog APV25 front-end chip and the Scalable Readout System (SRS) developed by the RD51 collaboration at CERN. Studies on small and large area GEM detectors, effects of mechanical stress, and of electric fields are presented. Sensitivity to defects in the readout plane is also verified.

Spatially resolved online particle detector using scintillators for laser-driven particle sources.

Laser-based particle accelerators have been an active field of research for over two decades moving from laser systems capable of one shot every hour to systems able to deliver repetition rates in the Hz regime. Based on the advancements in laser technology, the corresponding detection methods need to develop from single to multiple use with high readout speed. Here, we present an online compact trackerof particles using scintillators with nine resolvable energy levels and a spatial resolution of 3.6 × 3.6mm2 over the whole active area. This paper describes the designand construction of the detector, which is based on pixellated scintillators embedded inside an absorber matrix. The scintillator pixels are fiberoptically coupled to a camera system for online readout and analysis. Calibration with a radioactive source and first experimental data measuring laser accelerated ions at the PHELIX laser at GSI, Darmstadt, Germany, are presented and discussed.

A Low-Noise Instrumentation Amplifier With Built-in Anti-Aliasing for Hall Sensors

We present a compact, versatile Hall readout system with digital output, fully integrated in 180nm technology. The core of the system is an instrumentation amplifier architecture that provides inherent anti-aliasing filtering, where the anti-aliasing characteristic is locked into a shape that maximally prevents aliasing to low frequencies. The efficiency for blocking out-of-band white noise is comparable to that of a second-order filter, eliminating the need for an explicit anti-aliasing filter before the ADC. Chopping/spinning is applied for up-modulating offset and 1/f noise to just beyond the signal band. A mostly-digital ripple reduction loop (RRL) is added for mitigating offset-related dynamic range limitations. In this, a bilinear integrator is introduced for eliminating the impact of the RRL on the system's DC gain. Moreover, the resolution of the DAC generating the analog offset compensation is reduced significantly, and the effect thereof is eliminated by digital noise cancellation logic. The one-step amplification and the simple, low-resolution DAC for offset compensation both aid in keeping the area footprint low: the analog circuits (including DAC and ADC) only occupy 0.21mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Notable performance characteristics are an input-referred noise floor of 55nT/ √{Hz} within a 410kHz bandwidth, a current consumption of only 5.1mA, and a 47dB dynamic range. The amplifier architecture can be easily applied as an analog preconditioning circuit in other sensor readout situations as well.

Understanding and minimizing resonance frequency deviations on a 4-in. kilo-pixel kinetic inductance detector array

One of the advantages of kinetic inductance detectors is their intrinsic frequency domain multiplexing capability. However, fabrication imperfections usually give rise to resonance frequency deviations, which create frequency collision and limit the array yield. Here, we study the resonance frequency deviation of a 4-in. kilo-pixel lumped-element kinetic inductance detector (LEKID) array using optical mapping. Using the measured resonator dimensions and film thickness, the fractional deviation can be explained within ±25×10−3, whereas the residual deviation is due to variation of electric film properties. Using the capacitor trimming technique, the fractional deviation is decreased by a factor of 14. The yield of the trimming process is found to be 97%. The mapping yield, measured under a 110 K background, is improved from 69% to 76%, which can be further improved to 81% after updating our readout system. With the improvement in yield, the capacitor trimming technique may benefit future large-format LEKID arrays.

Plasmonic biosensor based on a gold nanostripe array for detection of microRNA related to myelodysplastic syndromes

We present a new optical biosensor based on surface plasmons excited on an array of gold nanostripes via attenuated total reflection. We investigate performance of the biosensor using a theoretical model that considers both optical and mass transport aspects. The analysis of optical aspects employs two different approaches: a complex model incorporating optical characteristics of the nanostructure as well as the noise characteristics of the optical readout system and a simple model based solely on the figure of merit of the nanostructure. The theoretical analysis suggests that the optimized biosensor is able to detect molecular analytes at concentrations lower by a factor of ~ 10 than conventional surface plasmon resonance biosensors. In order to validate the theoretical model, we characterize the gold nanostripe arrays of different designs in model refractometric and biosensing experiments. We show that the nanoplasmonic sensor exhibits refractive index sensitivity of 1989 nm/RIU and refractive index resolution down to 3.6×10−7RIU. In addition, we use the nanoplasmonic biosensor for the detection of a microRNA biomarker of myelodysplastic syndromes (miRNA-125b) and demonstrate that the biosensor can detect miRNA-125b at concentrations down to ~ 17 pM.

Readout Circuits for Capacitive Sensors.

The development of microelectromechanical system (MEMS) processes enables the integration of capacitive sensors into silicon integrated circuits. These sensors have been gaining considerable attention as a solution for mobile and internet of things (IoT) devices because of their low power consumption. In this study, we introduce the operating principle of representative capacitive sensors and discuss the major technical challenges, solutions, and future tasks for a capacitive readout system. The signal-to-noise ratio (SNR) is the most important performance parameter for a sensor system that measures changes in physical quantities; in addition, power consumption is another important factor because of the characteristics of mobile and IoT devices. Signal power degradation and noise, which degrade the SNR in the sensor readout system, are analyzed; circuit design approaches for degradation prevention are discussed. Further, we discuss the previous efforts and existing studies that focus on low power consumption. We present detailed circuit techniques and illustrate their effectiveness in suppressing signal power degradation and achieving lower noise levels via application to a design example of an actual MEMS microphone readout system.

No Glycation Required: Interference of Casein in AGE Receptor Binding Tests.

For the determination of the binding of heated cow’s milk whey proteins such as β-lactoglobulin to the receptors expressed on immune cells, inhibition ELISA with the soluble form of the receptor for advanced glycation end products (sRAGE) and scavenger receptor class B (CD36) has been successfully used in the past. However, binding to heated and glycated caseins in this read-out system has not been tested. In this study, inhibition ELISA was applied to measure the binding of cow’s milk casein alone, as well as all milk proteins together, which underwent differential heat treatment, to sRAGE and CD36, and we compared those results to a dot blot read out. Moreover, binding to sRAGE and CD36 of differentially heated milk protein was measured before and after in vitro digestion. Casein showed binding to sRAGE and CD36, independent from the heat treatment, in ELISA, while the dot blot showed only binding to high-temperature-heated milk protein, indicating that the binding is not related to processing but to the physicochemical characteristics of the casein. This binding decreased after passage of casein through the intestinal phase.

New Software-Based Readout Driver for the ATLAS Experiment

To maintain sensitivity to new physics in the coming years of Large Hadron Collider (LHC) operations, A Toroidal LHC ApparatuS (ATLAS) collaboration has been working on upgrading a portion of the front-end (FE) electronics and replacing some parts of the detector with new devices that can operate under the much harsher background conditions of future LHC runs. The legacy FE of the ATLAS detector sent data to the data acquisition (DAQ) system via the so-called Read Out Drivers (RODs) custom-made VMEbus boards devoted to data processing, configuration, and control. The data were then received by the Read Out System (ROS), which was responsible for buffering them during the High-Level Trigger (HLT) processing. From Run 3 onward, all new trigger and detector systems will be read out using new components, replacing the combination of the ROD and the ROS. This new path will feature an application called the Software Read Out Driver (SW ROD), which will run on a commodity server receiving FE data via the Front-End Link eXchange (FELIX) system. The SW ROD will perform event fragment building and buffering as well as serving the data on request to the HLT. The SW ROD application has been designed as a highly customizable high-performance framework providing support for detector-specific event building and data processing algorithms. The implementation that will be used for Run 3 of the LHC is capable of building event fragments at a rate of 100 kHz from an input stream consisting of up to 120 MHz of individual data packets. This document will cover the design and the implementation of the SW ROD application and will present the results of performance measurements executed on the server models selected to host SW ROD applications during Run 3.

Multichannel read-out for arrays of metallic magnetic calorimeters

Metallic magnetic micro-calorimeters (MMCs) operated at millikelvin temperature offer the possibility to achieve eV-scale energy resolution with high stopping power for X-rays and massive particles in an energy range up to several tens of keV. This motivates their use in a wide range of applications in fields as particle physics, atomic and molecular physics. Present detector systems consist of MMC arrays read out by 32 two-stage SQUID read-out channels. In contrast to the design of the detector array and consequently the design of the front-end SQUIDs, which need to be optimised for the physics case and the particles to be detected in a given experiment, the read-out chain can be standardised. We present our new standardised 32-channel parallel read-out for the operation of MMC arrays to be operated in a dilution refrigerator. The read-out system consists of a detector module, whose design depends on the particular application, an amplifier module, ribbon cables from room temperature to the millikelvin platform and a data acquisition system. In particular, we describe the realisation of the read-out system prepared for the ECHo-1k experiment for the operation of two 64-pixel arrays.The same read-out concept is also used for the maXs detector systems, developed for the study of the de-excitation of highly charged heavy ions by X-rays, as well as for the MOCCA system, developed for the energy and position sensitive detection of neutral molecular fragments for the study of fragmentation when molecular ions recombine with electrons.The choice of standard modular components for the operation of 32-channel MMC arrays offer the flexibility to upgrade detector modules without the need of any changes in the read-out system and the possibility to individually exchange parts in case of damages or failures.

Performance of the Unified Readout System of Belle II

The Belle II experiment at the SuperKEKB collider at KEK, Tsukuba, Japan has successfully started taking data with the full detector in March 2019. Belle II is a luminosity frontier experiment of the new generation to search for physics beyond the Standard Model of elementary particles, from precision measurements of a huge number of B and charm mesons and tau leptons. In order to read out the events at a high rate from the seven subdetectors of Belle II, we adopt a highly unified readout system, including a unified trigger timing distribution system (TTD), a unified high speed data link system (Belle2link), and a common backend system to receive Belle2link data. Each subdetector frontend readout system has a field-programmable gate array (FPGA) in which unified firmware components of the TTD receiver and Belle2link transmitter are embedded. The system is designed for data taking at a trigger rate up to 30 kHz with a dead-time fraction of about 1% in the frontend readout system. The trigger rate is still much lower than our design. However, the background level is already high due to the initial vacuum condition and other accelerator parameters, and it is the most limiting factor of the accelerator and detector operation. Hence the occupancy and radiation effects to the frontend electronics are rather severe, and they cause various kind of instabilities. We present the performance of the system, including the achieved trigger rate, dead-time fraction, stability, and discuss the experience gained during the operation.

PCI-Express Based High-Speed Readout for the Belle II DAQ Upgrade

Belle II is a new-generation B-factory experiment, dedicated to exploring new physics beyond the standard model of elementary particles in the flavor sector. Belle~II started data-taking in April 2018, using a synchronous data acquisition (DAQ) system based on pipelined trigger flow control. The Belle II DAQ system is designed to handle a 30-kHz trigger rate with approximately 1% of dead time, under the assumption of a raw event size of 1 MB. The DAQ system is reliable, and the overall data-taking efficiency reached 84.2% during the run period of January 2020 to June 2020. The current readout system cannot be operated in the term of 10 years from the viewpoint of DAQ maintainability; meanwhile, the readout system is obstructing high-speed data transmission. A solution involving a PCI-express-based readout module with high data throughput of up to 100 Gb/s was adopted to upgrade the Belle II DAQ system. We particularly focused on the design of firmware and software based on this new generation of readout board, called PCIe40, with an Altera Arria 10 field-programmable gate array chip. Forty-eight GBT (GigaBit Transceiver) serial links, PCI-express hard IP-based DMA architecture, interface of timing and trigger distribution system, and slow control system were designed to integrate with the current Belle II DAQ system. This paper describes the performances accomplished during the data readout and slow control tests conducted using a test bench and a demonstration performed using on-site front-end electronics, specifically involving Belle II TOP and KLM sub-detectors.

Data Acquisition System in the First Commissioning Run of the J-PARC E16 Experiment

J-PARC E16 is an experiment to examine the origin of hadron mass through a systematic measurement of spectral changes of vector mesons in nuclei. The measurement of e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> pairs from the decay of vector mesons will provide the information of the partial restoration of the chiral symmetry in a normal nuclear density. To resolve a pulse pile-up and achieve good discrimination of e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> and e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> from the background of a reaction rate of an order of 10 MHz, the data acquisition (DAQ) system uses waveform sampling chips of APV25 and DRS4. The trigger rate and data rate are expected to be 1 kHz and 120-330 MiB/s, respectively. The DAQ system for readout of APV25 and DRS4 were developed, where events were synchronized by common trigger and tag data. The first commissioning in beam, called Run-0a, was performed in June 2020 with about 1/4 of the designed setup. The DAQ worked with a trigger rate of 300 Hz in the Run-0a and the main bottleneck was a large data size of APV25. Further optimization of the DAQ system will improve the performance.

Automatic Test System of the Back-End Card for the JUNO Experiment

The Jiangmen Underground Neutrino Observatory (JUNO) is a medium-baseline neutrino experiment under construction in China, with the goal to determine the neutrino mass hierarchy. The JUNO electronics readout system consists of an underwater front-end electronics system and an outside-water back-end electronics system. These two parts are connected by 100-meter Ethernet cables and power cables. The back-end card (BEC) is the part of the JUNO electronics readout system used to link the underwater boxes to the trigger system is connected to transmit the system clock and triggered signals. Each BEC is connected to 48 underwater boxes, and in total around 150 BECs are needed. It is essential to verify the physical layer links before applying real connection with the underwater system. Therefore, our goal is to build an automatic test system to check the physical link performance. The test system is based on a custom designed FPGA board, in order to make the design general, only JTAG is used as the interface to the PC. The system can generate and check different data pattern at different speeds for 96 channels simultaneously. The test results of 1024 continuously clock cycles are automatically uploaded to PC periodically. We describe the setup of the automatic test system of the BEC and present the latest test results.