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Future space based particle physics experiments require detectors to be low power to ensure efficiency where no large amounts of energy can be continuously provided. The AstroPix chip aims for a power consumption of 1.5mW/cm2 and energy resolution of 2% at600keV per sensor. To determine the readiness of several wafers of different resistivities, 3 experiments were conducted. CV and IV data were taken using a probe station in SCIPP’s electronics room. The results determined that while the IV relationship looked normal for sensors with lower resistivities (from wafers 2 and 6), the sensors with higher resistivities (from wafers 10 and 11) had much higher current than anticipated, which inhibited the use of high voltage as breakdown occurred early.Another experiment consisted of taking data from a laser edge-TCT scan; this test confirmed the strange behavior of high resistivity chips as voltage amplitude pulses losttheir shape and amplitude with higher bias voltages which is contrary to intuition and the behavior of the lower resistivity chips. This led to the idea that with a high enough bias voltage, the leakage current incapacitates some of the transistors in W10 and W11 chips.The last experiment conducted was an infrared radiation scan of certain chips with the intention of furthering the investigation of the aforementioned anomalies. The result was that the backs of the high resistivity chips had different potentials than the fronts of the chips; when conducting tape was used on the backside of these chips, the current hit compliance (10mA) at a low voltage (10V). However, when using insulating tape or testing the chip on a metal chuck with probes in the high voltage and grounding pads, the chip was able to reach a higher voltage (220V) with the same current limit. This test shed lighton instances of higher power dissipation along the edges of certain chips which led to ideas about design flaws and differences in how different chips distributed current and dissipated power.

Digital pixel sensor (DPS) has evolved as a pivotal component in modern imaging systems and has the potential to revolutionize various fields such as medical imaging, astronomy, surveillance, IoT devices, etc. Compared to analog pixel sensors, the DPS offers high speed and good image quality. However, the introduced intrinsic complexity within each pixel, primarily attributed to the accommodation of the ADC circuit, engenders a substantial increase in the pixel pitch. Unfortunately, such a pronounced escalation in pixel pitch drastically undermines the feasibility of achieving high-density integration, which is an obstacle that significantly narrows down the field of potential applications. Nonetheless, designing compact conversion circuits along with strategic integration of 3D architectural paradigms can be a potential remedy to the prevailing situation. This review article presents a comprehensive overview of the vast area of DPS technology. The operating principles, advantages, and challenges of different types of DPS circuits have been analyzed. We categorize the schemes into several categories based on ADC operation. A comparative study based on different performance metrics has also been showcased for a well-rounded understanding.

A digital asynchronous logic is proposed as a generic matrix readout for Monolithic active pixel sensors. The architecture is implemented for pixel pitch ranging from 18 to 30 µm. Post-layout simulations with realistic hit shapes and rates up to 200 MHz/cm 2 show that time stamping at the 20 ns level can be achieved for a digital power cost below 10 mW/cm 2. [ABSTRACT FROM AUTHOR]

Abstract A position-sensitive pixel array silicon detector with a junction field effect transistor (JFET) switch structure is studied as a device for the direct illumination of X-ray from synchrotron light source. Considering an absorption length of silicon at an X-ray energy and a required thickness of a silicon, a 525 μ m n-type silicon wafer with high resistivity is chosen as the active volume of the detector and is depleted by applying a negative bias voltage to the junction side. The electron–hole pairs produced in an active volume by an X-ray illumination are collected on the electrodes. All pixels with one row are read in parallel and the next row is selected by the control voltage after one row has finished being read. The field shaper is introduced to produce inter-pixel isolation. We perform the simulation of the pixelated silicon position detector with JFET switch and present the characteristics of the transistor such as the drain current as a function of the voltage between the source and drain for different gate voltages. The fabrication processes of the pixel sensor with JFET switch structure based on the simulation result are also described. Highlights • Pixelated silicon detector with JFET switch structure is studied. • The simulation result shows that the switch performs well while controlling the gate voltage. • This detector concept can be applied for medical and radiation detectors. • Fabrication processes of the pixel sensor based on the simulation result are described. • Double metal structure for signal readout is employed and described. [ABSTRACT FROM AUTHOR]

This paper proposes a hydrogenated amorphous silicon thin-film transistor-based (a-Si:H TFT) optical pixel sensor. The proposed optical sensor compensates for variations of ambient light using photo TFTs that incorporate with three primary color filters, and a designed active load is utilized to release the photocurrent from the noise of reflected light. Measurement results reveal that the proposed sensor suppresses the effect of ambient light within the intensity of 12 560 lux and does not react to a blue light with an intensity of 588 lux, proving that the proposed optical sensor remains highly reliable under heavy ambient light and avoids the interference of reflected light.

We have been developing a new monolithic pixel sensor with silicon-on-insulator (SOI) technology for the International Linear Collider (ILC) vertex detector system. The SOI monolithic pixel detector is realized using standard CMOS circuits fabricated on a fully depleted sensor layer. The new SOI sensor SOFIST can store both the position and timing information of charged particles in each 20×20 μm 2 pixel. The position resolution is further improved by the position weighted with the charges spread to multiple pixels. The pixel also records the hit timing with an embedded time-stamp circuit. The sensor chip has column-parallel analog-to-digital conversion (ADC) circuits and zero-suppression logic for high-speed data readout. We are designing and evaluating some prototype sensor chips for optimizing and minimizing the pixel circuit. [ABSTRACT FROM AUTHOR]

We are developing advanced pixel sensors using silicon-on-insulator (SOI) technology. A SOI wafer is used; top silicon is used for electric circuit and bottom silicon is used as a sensor. Target applications are high-energy physics, X-ray astronomy, material science, non-destructive inspection, medical application and so on. We have developed two integration-type pixel sensors, FPIXb and INTPIX7. These sensors were processed on single SOI wafers with various substrates in n- or p-type and double SOI wafers. The development status of double SOI sensors and some up-to-date test results of n-type and p-type SOI sensors are shown. [ABSTRACT FROM AUTHOR]

Abstract: CMOS Pixel Sensors tend to become relevant for a growing spectrum of charged particle detection instruments. This comes mainly from their high granularity and low material budget. However, several potential applications require a higher read-out speed and radiation tolerance than those achieved with the available devices based on a feature size technology. This paper shows preliminary test results of new prototype sensors manufactured in a process based on a high resistivity epitaxial layer of sizeable thickness. Grounded on these observed performances, we discuss a development strategy over the coming years to reach a full scale sensor matching the specifications of the upgraded version of the Inner Tracking System (ITS) of the ALICE experiment at CERN, for which a sensitive area of up to may be equipped with pixel sensors. [Copyright &y& Elsevier]

Abstract: The PLUME (Pixelated Ladder with Ultra-Low Material Embedding) Collaboration is developing ultra-light ladders for the vertex detector for a future linear collider. The double-sided ladder will integrate the sensors, readout infrastructure and mechanical supports with the aim of total material budget of 0.3% of radiation length. The requirement of as light as possible construction is driven by physics, in particular by measurements requiring determination of the quark charge sign. The first prototype ladders were prepared and tested in the beam. The alignment issues for the ladders will be tested within the AIDA (Advanced European Infrastructures for Detectors at Accelerators) EU FP7 project. [Copyright &y& Elsevier]

Abstract: Design studies for an experiment searching for the lepton flavor violating decay μ→ eee are presented. The detector concept is based on thin layers of silicon sensors with fast readout. The aim of this experiment is to reach a sensitivity of B(μ→ eee) ≈ 10-16 corresponding to an improvement by a factor 10000 compared to previous experiments. [Copyright &y& Elsevier]

Abstract: CMOS monolithic active pixel sensors (MAPS) are proposed as a technology for various vertex detectors in nuclear and particle physics. We discuss the mechanisms of ionizing radiation damage on MAPS hosting the dead time free, so-called self bias pixel. Moreover, we introduce radiation hardened sensor designs which allow operating detectors after exposing them to irradiation doses above 1Mrad. [ABSTRACT FROM AUTHOR]

The first application of a pnCCD detector for X-ray scattering experiments using white synchrotron radiation at BESSY II is presented. A Cd arachidate multilayer was investigated in reflection geometry within the energy range 7 keV < E < 35 keV. At fixed angle of incidence the two-dimensional diffraction pattern containing several multilayer Bragg peaks and respective diffuse- resonant Bragg sheets were observed. Since every pixel of the detector is able to determine the energy of every incoming photon with a resolution ΔE/E ≃ 10-2, a three-dimensional dataset is finally obtained. In order to achieve this energy resolution the detector was operated in the so-called single-photon-counting mode. A full dataset was evaluated taking into account all photons recorded within 105 detector frames at a readout rate of 200 Hz. By representing the data in reciprocal-space coordinates, it becomes obvious that this experiment with the pnCCD detector provides the same information as that obtained by combining a large number of monochromatic scattering experiments using conventional area detectors. [ABSTRACT FROM AUTHOR]

Abstract: A beam telescope based on monolithic active pixel technology will be developed within the EUDET collaboration, a coordinated detector R&D programme for a future international linear collider. The telescope will consist of up to six sensor planes. The telescope can be operated inside a solenoidal magnetic field of up to . In addition, a general purpose cooling, positioning and readout infrastructure will be available. The telescope and the magnet will initially be installed at a electron beam line at DESY. However, the setup will be sufficiently flexible to be moved to higher energy hadron beam lines, for instance at CERN, in the future. Thus the telescope will provide a test environment for a wide variety of pixelated sensor technologies, while at the same time acting as a realistic test bed for tracking studies for a vertex detector at a future linear collider. [Copyright &y& Elsevier]

Nonepitaxial, high resistivity silicon has been used as a substrate for implementation of CMOS monolithic active pixel sensors (MAPS) designed for high precision minimum ionizing particle tracking. The readout electronics circuitry is integrated directly on top of such a substrate using a standard commercial CMOS process. in this paper, measurements of these devices using a high-energy particle beam are presented. Efficient and performing MIP tracking is demonstrated for both small (20 μm) and large (40 μm) pixel readout pitch. Radiation hardness that satisfies many future particle physics applications is also proven. These results show that the use of epitaxial substrate for MAPS fabrication is not mandatory, opening a much larger choice of possible CMOS processes in the future. [ABSTRACT FROM AUTHOR]

The development of particle tracker systems for high fluence environments in new high-energy physics experiments raises new challenges for the development, manufacturing and reliable testing of radiation tolerant components. The ATLAS pixel detector for use at the LHC, CERN, is designed to cover an active sensor area of 1.8 m2 with 1.1×108 read-out channels usable for a particle fluence up to 1015 cm−2 (1 MeV neutron equivalent) and an ionization dose up to 500 kGy of mainly charged hadron radiation. To cope with such a harsh environment the ATLAS Pixel Collaboration has developed a radiation hard n+-in-n silicon pixel cell design with a standard cell size of 50×400 μm2. Using this design on an oxygenated silicon substrate, sensor production has started in 2001. This contribution describes results gained during the development of testing procedures of the ATLAS pixel sensor and evaluates quality assurance procedures regarding their relevance for detector operation in the ATLAS experiment. The specific set of tests discussed in detail measures sensor depletion, interface generation velocity, p-spray dose and biasing by punch-through mechanism and is designed to give insights into effects of irradiation with ionizing particles. [Copyright &y& Elsevier]

An X-ray Active Matrix Pixel Sensor (XAMPS) for recording Data from the Scanning Transmission Electron Microscope (STEM) was designed, produced and tested. The reason for measuring scattering angle of all STEM electrons is given together with the requirement on the performance of the XAMPS. Principles of the measurement of the number of STEM electrons scattered in a particular direction are summarized. Results of tests performed on a produced detector are described and the problem with the formation of an insulation layer between silicon and aluminum is identified. A change in the design of the pixel is proposed which results in a fully functioning XAMPS even with the insulation layer present. [Copyright &y& Elsevier]

For the ATLAS Pixel Detector, prototype sensors have been successfully developed. For the sensors design, attention was given to survivability of the harsh LHC radiation environment leading to the need to operate them at several hundreds of volts, while maintaining a good charge collection efficiency, small cell size and minimal multiple scattering. For a cost effective mass production, a bias grid is implemented to test the sensors before assembly under full bias. [Copyright &y& Elsevier]

Abstract: For experiments at the European X-ray Free-Electron Laser (XFEL) the Adaptive Gain Integrating Pixel Detector (AGIPD) is under development. The particular requirements for the detector are a high dynamic range of 0, 1 to more than 104 12.4keV photons per pixel for an XFEL pulse duration of , and a radiation tolerance of 1GGy. The nominal operating voltage is 500V, however for special applications an operation close to 1000V should be possible. Experimental data on the dose dependence of the oxide-charge density at the Si–SiO2 interface and the surface-current density have been used in TCAD simulations and the layout of the pixels and guard-rings optimized. Finally the expected performance, in particular breakdown voltage, dark current and inter-pixel capacitance as function of X-ray dose are given. [Copyright &y& Elsevier]

Abstract: We report on ‘proof of concept’ experiments in pixel imaging mass spectrometry (PImMS) using an ultra-fast frame-transfer CCD camera. The fast framing CCD camera is capable of recording and storing on-chip up to 16 separate images corresponding to different mass fragments, with a time resolution of 10ns. In addition to the standard mass spectrum, the technique allows recording of the spatial or velocity distributions of the ions at their point of formation within the instrument. Our results unambiguously demonstrate the feasibility of technique, but it is also clear that the CCD camera restricts the total number of masses that may be imaged to an unacceptably small number. We describe possible CMOS pixel detectors capable of considerably improving the achieved performance in order to meet the demanding requirements for complete recording of mass spectra of complex organic molecules. [Copyright &y& Elsevier]