Readout Components Research Articles

The COLUTA ADC ASIC and the ATLAS HL-LHC Liquid Argon Front-End Readout

The upgraded High-Luminosity Large Hadron Collider (HL-LHC) requires a new radiation tolerant ATLAS Liquid Argon (LAr) Calorimeter readout operating at 40 MHz with 16-bit dynamic range. The Front-End Board 2 (FEB2) will provide the front-end readout for the calorimeter, and will interface a series of custom ASICs due to radiation tolerance requirements of the HL-LHC. The COLUTA is a 65 nm CMOS custom 8-channel 15-bit 40 MSPS ADC ASIC developed for this application. This contribution will present performance results of the final prototype of the COLUTA, surpassing specifications at >11.5 ENOB for relevant frequencies, as well as non-linearity and radiation requirements. Preliminary integration results of the front-end readout components will also be described by means of the FEB2 Pre-Prototype, the “Slice Testboard”.

A new data transfer scheme for the HL-LHC upgrade of the ATLAS Tile Hadronic Calorimeter

The Large Hadron Collider (LHC) is undergoing a series of upgrades towards a High Luminosity LHC (HL-LHC) that will deliver five times the LHC nominal instantaneous luminosity. The ATLAS experiment is one of the experiments at the LHC that investigates elementary particle interactions in collisions of high-energy proton beams. To prepare for data taking in high-luminosity conditions, the ATLAS Tile Hadronic Calorimeter (TileCal) will replace completely on- and off-detector electronics using a new read-out architecture. The TileCal detector signals will be digitized by on-detector electronics and transferred to the TileCal PreProcessors (TilePPr), which comprise the main component of the off-detector electronics. In the TilePPr, the digitized data will be stored in pipeline buffers and be packed and read out to the Front-End LInk eXchange (FELIX) system upon the reception of a trigger decision. FELIX is a new detector readout component being developed as part of the ATLAS upgrade effort. FELIX is designed to act as a data router between the data acquisition detector control and TTC (Timing, Trigger and Control) systems and the new or updated trigger and detector front-end electronics. Whereas previous detector readout implementations relied on diverse custom hardware platforms, the idea behind FELIX is to unify all readout across one well supported and flexible platform.

Resistivity study of inkjet-printed structures and electrical interfacing on flexible substrates

Development and evaluation of electronics with printing techniques such as inkjet printing is currently an active subject of research with various outstanding results in sensing applications. Printing technologies have shown high efficiency and compatibility with various types of inks and substrates, enhancing the opportunity for scientific innovation and research in this field. The present work reports on the evaluation of the resistivity and the sheet resistance of inkjet-printed conductive commercial Ag-nanoparticle ink, graphene ink and a custom functionalized reduced graphene oxide ( f- rGO) ink on Kapton substrate using the Van-der-Pauw method. Two different approximations have been used to determine the sheet resistance (R s ) and the corresponding resistivity (ρ). The results showed differences in the extracted sheet resistance value, which emphasizes the importance of the adopted calculation method. Furthermore, in order to demonstrate the ability to fabricate printed structures with efficient electrical connection to external devices, we have evaluated standard methods for interfacing two inkjet-printed materials on Kapton substrate, namely: commercial Ag-nanoparticle ink and graphene ink. Two standard connection techniques implementing a 4-pin Flexible Printed Circuit (FPC) connector and an Amphenol Clincher connector were evaluated, along with a custom direct interconnection approach. Direct interconnection between Cu patterned tracks and printed structures attracts special interest because it addresses one of the main problems in printed electronics, which is the interfacing of the printed structure with other electronic or read-out components. Thus, the printed Ag-Graphene/Cu direct interconnection case was further investigated. Two-point [2p] and four-point [4p] measurements were performed in order to study the effect of the various probe locations of engagement to the extracted resistance. The results acquired for this interconnection method revealed the importance of the measurement probe location. To support these experimental results, FEA simulations were performed and the outcomes were consistent with the experimental findings. • Two approaches in the calculation process of sheet resistance, implementing Van-der-Pauw test structures showed the significance of the evaluation method to the results. • Application-level approaches for electrical interfacing, which utilize copper interconnections are presented and evaluated. • Both Ag ink and graphene ink can be inkjet-printed onto Kapton substrate and used as a reliableinterconnection method. • Direct interconnections revealed how the probe location, the contact resistance and the localization of electric field affect the measurement process.

The Simons Observatory Microwave SQUID Multiplexing Detector Module Design

Abstract Advances in cosmic microwave background (CMB) science depend on increasing the number of sensitive detectors observing the sky. New instruments deploy large arrays of superconducting transition-edge sensor (TES) bolometers tiled densely into ever larger focal planes. High multiplexing factors reduce the thermal loading on the cryogenic receivers and simplify their design. We present the design of focal-plane modules with an order of magnitude higher multiplexing factor than has previously been achieved with TES bolometers. We focus on the novel cold readout component, which employs microwave SQUID multiplexing (μmux). Simons Observatory will use 49 modules containing 70,000 bolometers to make exquisitely sensitive measurements of the CMB. We validate the focal-plane module design, presenting measurements of the readout component with and without a prototype detector array of 1728 polarization-sensitive bolometers coupled to feedhorns. The readout component achieves a 95% yield and a 910 multiplexing factor. The median white noise of each readout channel is 65 pA / Hz . This impacts the projected SO mapping speed by <8%, which is less than is assumed in the sensitivity projections. The results validate the full functionality of the module. We discuss the measured performance in the context of SO science requirements, which are exceeded.

Integrated Resonant Micro/Nano Gravimetric Sensors for Bio/Chemical Detection in Air and Liquid.

Resonant micro/nanoelectromechanical systems (MEMS/NEMS) with on-chip integrated excitation and readout components, exhibit exquisite gravimetric sensitivities which have greatly advanced the bio/chemical sensor technologies in the past two decades. This paper reviews the development of integrated MEMS/NEMS resonators for bio/chemical sensing applications mainly in air and liquid. Different vibrational modes (bending, torsional, in-plane, and extensional modes) have been exploited to enhance the quality (Q) factors and mass sensing performance in viscous media. Such resonant mass sensors have shown great potential in detecting many kinds of trace analytes in gas and liquid phases, such as chemical vapors, volatile organic compounds, pollutant gases, bacteria, biomarkers, and DNA. The integrated MEMS/NEMS mass sensors will continuously push the detection limit of trace bio/chemical molecules and bring a better understanding of gas/nanomaterial interaction and molecular binding mechanisms.

The Simons Observatory: Magnetic Sensitivity Measurements of Microwave SQUID Multiplexers

The Simons Observatory (SO) will be a cosmic microwave background (CMB) survey experiment with three small-aperture telescopes and one large-aperture telescope, which will observe from the Atacama Desert in Chile. In total, SO will field ~70,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz in order to achieve the sensitivity necessary to measure or constrain numerous cosmological quantities. The SO Universal Focal Plane Modules (UFMs) each contain a 150 mm diameter TES detector array, horn or lenslet optical coupling, cold readout components, and magnetic shielding. SO will use a microwave SQUID multiplexing (μMUX) readout at an initial multiplexing factor of ~1000; the cold (100 mK) readout components are packaged in a μMUX readout module, which is part of the UFM, and can also be characterized independently. The 100 mK stage TES bolometer arrays and microwave SQUIDs are sensitive to magnetic fields, and their measured response will vary with the degree to which they are magnetically shielded. We present measurements of the magnetic pickup of test microwave SQUID multiplexers as a study of various shielding configurations for the Simons Observatory. We discuss how these measurements motivated the material choice and design of the UFM magnetic shielding.

Trigonal Bipyramidal V3+ Complex as an Optically Addressable Molecular Qubit Candidate.

Synthetic chemistry enables a bottom-up approach to quantum information science, where atoms can be deterministically positioned in a quantum bit or qubit. Two key requirements to realize quantum technologies are qubit initialization and read-out. By imbuing molecular spins with optical initialization and readout mechanisms, analogous to solid-state defects, molecules could be integrated into existing quantum infrastructure. To mimic the electronic structure of optically addressable defect sites, we designed the spin-triplet, V3+ complex, (C6F5)3trenVCNtBu (1). We measured the static spin properties as well as the spin coherence time of 1 demonstrating coherent control of this spin qubit with a 240 GHz electron paramagnetic resonance spectrometer powered by a free electron laser. We found that 1 exhibited narrow, near-infrared photoluminescence (PL) from a spin-singlet excited state. Using variable magnetic field PL spectroscopy, we resolved emission into each of the ground-state spin sublevels, a crucial component for spin-selective optical initialization and readout. This work demonstrates that trigonally symmetric, heteroleptic V3+ complexes are candidates for optical spin addressability.

Development of Heavy Metal Potentiostat for Batik Industry

The consumption of reactive dyes in the batik industry has led to a severe concern in monitoring the heavy metal level in wastewater. Due to the necessity of implementing a wastewater monitoring system in the batik factory, a Heavy Metal potentiostat (HMstat) was designed. The main goal of this study is to understand the optimal design concept of the potentiostat function in order to investigate the losses of accuracy in measurement using off-the-shelf devices. Through lab-scale design, the HMstat comprises of an analog potentiostat read-out circuit component (PRCC) and a digital control signal component (CSC). The PRCC is based on easy to use components integrated with a NI-myRIO controller in a CSC. Here, the myRIO was equipped with built-in analog to digital converter (ADC) and digital to analog converter (DAC) components. In this paper, the accuracy test and detection of cadmium(II) (Cd2+) and lead(II) (Pb2+) were conducted using the HMstat. The results were compared with the Rodeostat (an open source potentiostat available on the online market). The accuracy of the HMStat was higher than 95% and within the precision rate of the components used. The HMstat was able to detect Cd2+ and Pb2+ at −0.25 and −0.3 V, respectively. Similar potential peaks were obtained using Rodeostat (Cd2+ at −0.25 V and Pb2+ at −0.3 V).

Self-Powered Potentiometric Sensor Transduction to a Capacitive Electronic Component for Later Readout.

Potentiometric sensors operate as galvanic cells where the voltage is spontaneously generated as a function of the sample composition. We show here that energy can be harvested, stored during the sensing process without external power, and physically isolated from the sensor circuit for later readout. This is accomplished by placing an electronic capacitor as a portable transduction component between the indicator and the reference electrode at the point where one would ordinarily connect the high-input-impedance voltmeter. The voltage across this isolated capacitor indicates the originally measured ion activity and can be read out conveniently, for example, using a simple handheld multimeter. The capacitor is shown to maintain the transferred charge for hours after its complete disconnection from the sensor. The concept is demonstrated to detect the physiological concentrations of K+ in artificial sweat samples. The methodology provides a readout principle that could become very useful in portable form factors and opens possibilities for potentiometric detection in point-of-care applications and inexpensive sensing devices where an external power source is not desired.

Beam test of a PIN-diode read out PWO calorimeter with electron energies from 5 to 40 GeV at CERN SPS

The Chinese large-area violet-light-sensitive silicon photodiode PIN is one of the candidates of the lead tungstate crystal detector readout component of the photon spectrometer in the large heavy ion collision experiment. The PIN diode was assembled with the lead tungstate crystal and the low-noise preamplifier into a complete detector unit. The beam test was carried out on the SPS accelerator at CERN. The energy resolution was measured with the electron beam energy ranging from 5 to 40 GeV. The summation correction method was discussed, and an excellent linearity of the nominal beam energy versus the peak position of the detector was obtained, which showed the punch-through effect can be ignored.

Interfacial composition, structure, and properties of ionic liquids and conductive polymers for the construction of chemical sensors and biosensors: a perspective

The fields of chemical and biosensors have grown tremendously from the improvements in the transducer and readout components, as well as in sensing materials and interface designs to meet the always rising standards for accuracy, cost, portability, and accessibility in a broad range of sensing applications. Although the transducer and readout components can often be interchangeable for a specific target analyte, the receptor element of the sensor device, which is the ‘sensing material with its interface chemistry,’ must be specifically tailored to any sensing mechanism. The interfacial properties of the sensing components play essential roles in determining the analytical performance and the overall cost of the sensor technology in both technical and commercial senses. Ionic liquids (IL) are liquids often composed of bulky organic cations or anions, whereas conductive polymers (CPs) are solids with dopant ions in a rigid organic framework. Both ILs and CPs have been demonstrated as promising smart/tunable and low-cost materials for chemical and biosensor development. In this article, we present our opinion discussing the unique features of using ILs and CPs as molecular building blocks to design robust and functional sensing interfaces for next-generation, low-cost, and miniaturized electrochemical sensor development.

Toward 100,000-Pixel Microcalorimeter Arrays Using Multi-absorber Transition-Edge Sensors

We report on the development of multi-absorber transition edge sensors (TESs), referred to as hydras. A hydra consists of multiple x-ray absorbers each with a different thermal conductance to a TES. Position information is encoded in the pulse shape. With some trade-off in performance, hydras enable very large format arrays without the prohibitive increase in bias and read-out components associated with arrays of individual TESs. Hydras are under development for the next generation of space telescope such as Lynx. Lynx is a NASA concept under study that will combine a < 1 arcsecond angular resolution optic with 100,000-pixel microcalorimeter array with energy resolution of deltaE_FWHM ~ 3 eV in the soft x-ray energy range. We present first results from hydras with 25-pixels for Lynx. Designs with absorbers on a 25 micron and 50 micron pitch are studied. Arrays incorporate, for the first time, microstrip buried wiring layers of suitable pitch and density required to readout a full-scale Lynx array. The resolution from the coadded energy histogram including all 25-pixels was deltaE_FWHM = 1.66+/-0.02 eV and 3.34+/-0.06 eV at an energy of 1.5 keV for the 25 micron and 50 micron absorber designs respectively. Position discrimination is demonstrated from parameterization of the rise-time.

Minimizing CPU Utilization Requirements to Monitor an ATLAS Data Transfer System

The ATLAS experiment at LHC will use a PC-based read-out component called FELIX to connect its front-end electronics to the Data Acquisition System. FELIX translates custom front-end protocols to Ethernet and vice versa. Currently, FELIX makes use of parallel multi-threading to achieve the data rate requirements. In order to establish the FELIX operation conditions, monitoring of its parameters is necessary. This includes, but is not limited to, data counters and rates as well as compute resource utilisation. However, for these statistics to be of practical use, the parallel threads are required to intercommunicate. The FELIX monitoring implementation prior to this research utilized thread-safe queues to which data was pushed from the parallel threads. A central thread would extract and combine the queue contents. Enabling statistics would deteriorate the throughput to less than a fifth of the baseline performance. To minimize this performance hit to the greatest extent, we take advantage of the CPU's microarchitecture features and reduce concurrency. The focus is on hardware-supported atomic operations. When a thread performs an atomic operation, the other threads see it as happening instantaneously. They are used to complement and/or replace parallel computing lock mechanisms. The aforementioned queue system gets replaced with sets of C/C++ atomic variables and corresponding atomic functions, hereinafter referred to as atomics. Three implementations are tested. Implementation I has one set of atomic variables being updated by all the parallel threads. Implementation II has a set of atomic variables for every thread. These sets are periodically accumulated by a central thread. Implementation III is the same as implementation II, but appropriate measures are taken to eliminate any concurrency implications. The compiler used during the measurements is GCC, which supports the hardware (microarchitecture) optimizations for atomics. Implementations I and II resulted in negligible differences compared to the original one. Some benchmarks even show deterioration of the performance. Implementation III (concurrency & cache optimized) yields results with a performance improvement of up to six-fold increase compared to the original implementation. Achieved throughput is significantly closer to what is desirable. Similar structured software applications could benefit from the results of this research, especially Implementation III. The results presented demonstrate that atomics can be useful for efficient computations in a multi-threaded environment. However, from the results, it is clear that concurrency, cache invalidation and proper usage of the system's microarchitecture needs to be taken into account in this programming model. The paper details the challenges of properly using atomics and how they are overcome in the implementation of the FELIX monitoring system.

Development of a silicon strip detector for novel accelerators at SINBAD

At the SINBAD facility (DESY Hamburg), novel particle acceleration techniques like dielectric laser acceleration (DLA) structures will be tested using the ARES linac. Due to the small size of these structures, the accelerated electron beams only have a very low (sub-pC) charge. To determine the energy distribution of these beams, a silicon strip detector for the ARES linac spectrometer is currently under development. This detector fulfils the requirements of high spatial resolution for low charge density beams. The detector consists of two 1 cm × 1 cm silicon strip sensors and readout components. The design of the detector, its components and an estimate of its behaviour for a specific electron beam distribution are presented and discussed.

Commercially Fabricated Low Loss Superconducting Resonators Integrated With Detectors for Frequency Domain Multiplexing Readout of Future Cosmic Microwave Background Experiments

Planned Stage-IV cosmic microwave background (CMB) experiments call for telescopes with the order of 500 000 transition edge sensor (TES) bolometers. Such large arrays would benefit from detector multiplexing, as well as miniaturization and integration of readout components. In addition, fabrication of micro-fabricated devices at a commercial foundry could potentially boost production rate and reduce overall cost. To this end, HYPRES, Inc., LBNL, and U.C. Berkeley are developing low loss, superconducting LC resonators integrated with antenna coupled TES bolometers for frequency multiplexing readout. The resonators are fabricated on the same wafer and are in the same process flow as the TES detectors, reducing size, weight, and wiring complexity of a detector module compared to the conventional design, where each component is fabricated separately. We have fabricated and tested resonators from 0.6 to 70 MHz, both as standalone devices and integrated with TES bolometers, all fabricated on 150- mm wafers. We discuss the design and fabrication of these devices and present measurements of the standalone resonators.

Strategy and automation of the quality assurance testing of MaPMTs for the LHCb RICH upgrade

The LHCb RICH system will undergo major modifications for the LHCb Upgrade during the Long Shutdown 2 of the LHC, and the current hybrid photon detectors will be replaced by Multi Anode PMTs. The operating conditions of the upgraded experiment put forth significant requirements onto the sensors in terms of their performance, durability & reliability as the upgraded RICH is supposed to operate for 10 years. An overview of the testing facilities designed and used to vet 3100 units of Hamamatsu R13742 and 450 units of Hamamatsu R13743 during the short 2 year testing period is presented. The hardware architecture, the read-out, power and control components, as well as the novel extensible software framework to steer the procedure are discussed. Finally, the operation of 4 automated stations, that have been deployed in two separate labs, is reported, with each station capable of fully characterising 16 MaMPTs per day.

Abstract B074: A recall antigen-based potency assay for immunomodulatory biologics that could discriminate responders from nonresponders

Abstract The surge of therapeutic regimens involving immune checkpoint antagonists and co-stimulatory pathways (ACP) antagonists used as single agents or in combination necessitates better functional screening assays. In vitro functional screening assays need to be non-invasive and high throughput. The recall antigen assay is arguably the one that, in an antigen specific controlled system, directly assesses the activity of potential immune checkpoint inhibitors (ICI) candidates, in a relatively physiologically relevant manner. The recall antigen assay has been often used in the past to prove the potency of ICI or ACP as indicated in publications and submissions to regulatory bodies. We have conducted a thorough optimization combined with modifications to the recall antigen assay to enable the need for a more effective and efficient assay.Our recall antigen assay has been optimized across multiple parameters including donor selection based on expression of co-inhibitory/co-stimulatory molecules. This facilitates the selection of the right donor for the right candidate. We have optimized both stimulation and readout components to enhance signal to noise ratio. For example, we reduced the duration of in vitro antigen specific CD8+ T-cell clonotype expansion from 2 weeks to 5 to 7 days. To maximize the direct readout, we have used an MHC Tetramer guided analysis, using a cocktail of MHC tetramers made with stimulating peptides. To further empower the tetramer assay with functionality, we also have co-stained tetramer positive cells with activation markers. Finally, we verified the assay using various activity-confirmed ICIs and controls. The assay uses characterized PBMCs stimulated with a pool of peptides with positive and negative treatments (e.g., PD-1 blockades and IgG4) and “test samples,” which are the candidates to be tested. Depending on the donor’s recall responses, a typical assay results in two to 6-fold increase of the antigen specific MHC tetramer positive population. Furthermore, after developing this recall antigen assay, we validated it by performing the assay in different laboratories, using different reagents lots, different instrumentations, and different operators. Recall antigen assay data indicated that not all donors respond to approved immune checkpoint blockades. Healthy donors stimulated with anti CD3 or cytokine cocktails varied showed a wide a wide variability of immune checkpoint molecules (ICM) cell surface levels. Further studies using characterized PBMCs in our recall antigen potency assay revealed that the expression of immune checkpoint molecules may contribute in unresponsiveness to a given ICI. In conclusion, we have developed an improved in vitro recall antigen potency assay for immunomodulatory biologics functional screening including ICIs and APCs. Furthermore, we observed that in our studies this potency assay divides hosts into responders and nonresponders. Interestingly, we also showed significant variation of persons’ PBMC responses to ICIs, which may be related to their inherent expression levels of immune checkpoint molecules. We intend to confirm this finding with further studies using well-annotated clinical samples. Citation Format: Marc Delcommenne, Eden Kleiman, Wushouer Ouerkaxi, Pirouz Daftarian. A recall antigen-based potency assay for immunomodulatory biologics that could discriminate responders from nonresponders [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B074.

Integrated readout electronics for Belle II pixel detector

This paper describes the readout components for Belle II that have been designed as integrated circuits. The ICs are connected to DEPFET sensor by bump bonding. Three types of ICs have been developed: SWITCHER for pixel matrix control, DCD for readout and digitizing of sensor signals and DHP for digital data processing. The ICs are radiation tolerant and use several novel features, such as the multiple-input differential amplifiers and the fast and radiation hard high-voltage drivers. SWITCHER and DCD have been developed at University of Heidelberg, Karlsruhe Institute of Technology (KIT) and DHP at Bonn University. The IC-development started in 2009 and was accomplished in 2016 with the submissions of final designs. The final ICs for Belle II pixel detector and the related measurement results will be presented in this contribution.

Dual-Gate Photosensitive Thin-Film Transistor-Based Active Pixel Sensor for Indirect-Conversion X-Ray Imaging

Over the past century, the conventional film-based radiographic X-ray imaging has evolved into digital radiography (DR). Amorphous silicon thin-film transistor (TFT)-based flat panel X-ray detector was introduced two decades ago, and has become a ubiquitous platform for several imaging modalities, including chest radiography, mammography, and fluoroscopy. As a fundamental building block, an advanced pixel has thus been developed to tackle clinical challenges. However, all types of pixel architectures, either passive or active, unanimously keep sensing, storage, and readout components separate. This is disadvantageous in further reducing pixel size and improving spatial resolution. To address these problems, we hereby propose a novel architecture, which combines the abovementioned three functional units in one single dual-gate photo-TFT. In other words, the dual-gate photo-TFT alone works as a sensor, a storage, and a switch. In addition, by harnessing the amplification effect of TFT, it, for the first time, realizes one single-transistor active pixel sensor that makes a tremendous promise in achieving low-dose X-ray imaging for DR. In this paper, the proof-of-concept device was fabricated using the conventional amorphous silicon TFT technology and the device was characterized in a series of measurements of electrical and optoelectronic performance.

Population gratings in saturable optical fibers with randomly oriented rare-earth ions

Formation of the dynamic population gratings in optical fibers with randomly oriented rare-earth ions is analyzed with a special interest to the grating component for readout with the orthogonal light polarization. It is shown that as compared with a simple model case of the collinearly oriented dipole-like centers their random orientation leads to approximately 2-times growth of the effective saturation power Psat when it is estimated from the incident power dependence of the fiber absorption or from that of the fluorescence intensity. An optimal incident power, for which the maximum of the dynamic population grating amplitude for collinear light polarization is observed, also follows this change in Psat, while formation of the grating for orthogonal polarization needs essentially higher light power. The reduced anisotropy of the active centers, which is in charge of the experimentally observed weakening of the polarization hole burning (PHB) and of the fluorescence polarization, compensates in some way the effect of random ion orientation. The ratio between the maximum conventional (i.e. for the interacting waves collinear polarizations) two-wave mixing (TWM) amplitude and the initial not saturable fiber optical density proves to be, however, nearly the same as in the model case of collinearly oriented dipoles. The ratio between the PHB effect and the amplitude of the anisotropic grating, which is responsible for TWM of the orthogonally polarized waves, is also not influenced significantly by the reduced anisotropy of ions.