Entity

Time filter

Source Type

München, Germany

Porro M.,Max Planck Institute for Extraterrestrial Physics | Andricek L.,MPI Halbleiterlabor | Andricek L.,Max Planck Institute for Physics | Bombelli L.,Polytechnic of Milan | And 10 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2010

The new DSSC (DEPFET sensor with signal compression) detector system is being developed in order to fulfil the requirements of the future XFEL in Hamburg. The instrument will be able to record X-ray images with a maximum frame rate of 5 MHz and to achieve a high dynamic range. The system is based on a silicon pixel sensor with a new designed non-linear-DEPFET as a central amplifier structure. The detector chip is bump-bonded to mixed signal readout ASICs that provide full parallel readout and temporary data storage. The signals coming from the detector are processed by an analog filter, immediately digitized by 8-ENOB ADCs and locally stored in a custom designed memory. The ASICs are designed in 130 nm CMOS technology. During the time gap of 99 ms of the XFEL machine, the digital data are sent off the focal plane to a DAQ electronics that acts as an interface to the back-end of the whole instrument. The pixel sensor has been designed so as to combine high energy resolution at low signal charge with high dynamic range. This has been motivated by the desire to be able to be sensitive to single low energy photons and, at the same time, to measure at other positions of the detector signals corresponding to up to 104 photons of 1 keV. In order to fit this dynamic range into a reasonable output signal swing, achieving at the same time single photon resolution, a strongly non-linear characteristic is required. The new proposed DEPFET provides the required dynamic range compression at the sensor level, considerably facilitating the task of the electronics. At the same time the DEPFET charge handling capacitance is enormously increased with respect to standard DEPFETs. The sensor matrix will comprise 1024×1024 pixels of hexagonal shape with a side-length of 136μm. The simultaneous implementation of the 5 MHz frame rate, of the single low-energy photon resolution and of the high dynamic range goes beyond all the existing instruments and requires the development of new concepts and technologies. © 2010 Elsevier B.V. All rights reserved. Source


Porro M.,Max Planck Institute for Extraterrestrial Physics | Bianchi D.,Polytechnic of Milan | De Vita G.,Max Planck Institute for Extraterrestrial Physics | Hartmann R.,PNSensor GmbH | And 6 more authors.
IEEE Transactions on Nuclear Science | Year: 2013

VERITAS (VErsatile Readout based on Integrated Trapezoidal Analog Shapers) is the first 128-channel ASIC developed to read out both the pnCCDs and the DEPFET arrays produced at the MPI-Halbleiterlabor in Munich. These detectors are used in a large variety of scientific applications, ranging from high-speed optical astronomy and X-ray astronomy to the new X-ray Free Electron Laser sources. The main concept of VERITAS is to provide a flexible readout chip able to cope not only with different kinds of detectors, but also with a large set of operating conditions that may require very different noise thresholds and input dynamic ranges. These can vary by more than two orders of magnitude. Every analog channel of VERITAS provides a trapezoidal weighting function. This filtering strategy had never been applied to the pnCCD before. The very first measurements obtained coupling VERITAS with a 128×,256 pnCCD are shown. With a readout time of 4 μ s/line a noise of 3.9 electrons has been measured in the highest gain mode. The resolution obtained on the Mn-Kα peak of a 55Fe source is 136 eV for single events. A noise of 30 electrons has been achieved in the lowest gain mode at a speed of 6.4 μ s/line. In this low gain setting an input charge up to 2.5× 105 electrons can be processed. These striking results fulfill the requirements of the main foreseen applications of large-size pnCCDs. In order to further improve the performance and the flexibility of the ASIC, a second version based on a fully differential architecture has been designed. The new topology allows one also to switch with the same ASIC between the source follower and drain current readout of the DEPFET sensors and to reach a processing time of about 2-3 μs/line with an electronics noise ≤10 el. For this reason the second version of VERITAS is very attractive for the proposed ESA X-ray astronomy mission ATHENA. © 1963-2012 IEEE. Source


Bombelli L.,Polytechnic of Milan | Bombelli L.,National Institute of Nuclear Physics, Italy | Fiorini C.,Polytechnic of Milan | Fiorini C.,National Institute of Nuclear Physics, Italy | And 4 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2010

The concept of active pixel sensor based on depleted P-channel FET (DEPFET) has been developed to cope with the emerging requirements of low noise and speed. The DEPFET detector/amplifier [1], thanks to an intrinsic low anode capacitance, can provide excellent energy resolution and fast readout at the same time. However, in order to fully exploit the speed capability, it is necessary to develop a new readout electronics, which is different from the ones employed up to now. For this purpose, we have developed a new front-end ASIC, named VLSI Electronic for Astronomy (VELA). The implemented circuit operates the pixels in a new current readout configuration to implement an extremely fast readout. The current version of VELA reads out 64 × 64 DEPFET matrixes with unparalleled frame rate and excellent energy resolution. The circuit architecture, the working principle, and the VELA suitability for X-ray imaging will be shown. © 2009 Elsevier B.V. All rights reserved. Source


Porro M.,Max Planck Institute for Extraterrestrial Physics | De Vita G.,Max Planck Institute for Extraterrestrial Physics | Herrmann S.,Max Planck Institute for Extraterrestrial Physics | Lauf T.,Max Planck Institute for Extraterrestrial Physics | And 8 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2010

The 64 channel ASTEROID ASIC has been developed to readout DEPFET Macro-Pixel Arrays operated in source follower mode. In particular ASTEROID will be coupled with the DEPFET Macro-Pixel sensors designed for the X-ray astronomy application BepiColombo. This is a satellite-based mission that requires a detector system with high speed readout, high energy resolution and radiation hardness properties. In the source follower operating mode of the DEPFETs, the front-end electronics is AC-coupled. This allows easy coping with non homogeneity of the pixel matrix and an easy compensation of threshold voltage shifts of the DEPFET devices due to radiation damage. In order to achieve the low noise value required at short processing time, ASTEROID implements a trapezoidal weighting function. This is the time-limited optimum filter for white series noise, which is dominant at the foreseen readout speed. The ASIC is realized in the 0.35 μm 3.3 V AMS CMOS technology. The outputs of the 64 analog channels are multiplexed to one serial output with a speed up to 20 MHz. Thanks to the new multiplexer architecture adopted, ASTEROID is the only ASIC that allows window-mode readout of the pixel matrices, i.e. that allows to address selectively arbitrary sub-areas of the pixel array or even to readout different sub-areas at different speeds. In order to fully operate the 64 channels in parallel, the ASIC contains a digital section that generates the timing signals for the analog circuits. This digital section is based on SEU-immune dual port memory cells. ASTEROID has been tested for the first time with a demonstrator 64 × 64 macro-pixel Matrix of the size of 3.2 × 3.2 cm2. The energy resolution measured on the Mn - kα peak of 55Fe is of 124eV with a pixel processing time of 4.8 μs at - 80°C. This excellent result, never achieved before with source follower DEPFET at this readout speed, perfectly matches the requirements of BepiColombo Mission. © 2009 Elsevier B.V. All rights reserved. Source


Busca P.,Polytechnic of Milan | Busca P.,National Institute of Nuclear Physics, Italy | Peloso R.,Polytechnic of Milan | Peloso R.,National Institute of Nuclear Physics, Italy | And 9 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2010

Silicon drift detectors (SDDs) have shown to be a competitive device for the readout of scintillators with respect to conventional photodetectors, thanks to their high quantum efficiency and low electronics noise. Recently, they have been successfully employed in first small prototypes of Anger cameras to achieve sub-millimeter spatial resolution in gamma-ray imaging. To cover larger formats of Anger cameras, in particular in the framework of the HICAM project, specially focused on human imaging, we have developed new SDD arrays of larger active areas. To assemble photodetector planes of several cm2, we have designed a basic unit composed by a linear array of 5 SDDs of 1 cm 2 active area each. In this work, we present the results of the experimental characterization of these photodetector arrays in direct X-ray detection to evaluate the electronics noise, as well as gamma-ray detection with a scintillator. © 2010 Elsevier B.V. All rights reserved. Source

Discover hidden collaborations