Search

The Circular Electron Positron Collider (CEPC) is a proposing electron–positron collider in China, which aims for generating high center-of-mass energy colliding above 250 GeV. The high-granularity electromagnetic calorimeter (ECAL) is included in a calorimeter system, which is mainly responsible for the measurement of photon. A particle flow algorithm (PFA)-based ECAL solution will utilize about 400k channels/m3. Here, we present the design and development status of readout electronics based on SPIROC2b for the CEPC ECAL with high-granularity scintillants and silicon photomultipliers (SiPMs). The readout electronics consists of front-end electronics (FEE), data interface (DIF) board, and data acquisition (DAQ) board. The front-end board (FEB) carries SiPMs (S12571-010P), scintillants (PSD), and FEB application-specific integrated circuit (ASIC) (SPIROC2b). Two electronics were designed in this paper, one is for ASIC functionality and performance only, and the other is used as a single layer of a further prototype of ECAL. Electronic test and cosmic ray test have been done to electronics. The results indicate that a charge dynamic from 62 fC to 300 pC at S/N = 2 is successfully achieved, and the minimum ionizing particles (MIPs) are separated from the pedestal. [ABSTRACT FROM AUTHOR]

We designed a CMOS frontend for the readout of scintillators coupled with silicon photodiodes for nuclear physics experiments. The preamplifier features a continuous-reset feedback and an input pMOS transistor. The designed input dynamic range is 90-MeV silicon equivalent. The frontend has been integrated in single channel and multichannel versions up to 16-channel application specific integrated circuits (ASICs) in the C35B4C3 AMS technology. The measured integral-non-linearity over the whole dynamic range is below 0.5%. The intrinsic rise time (10%–90%) of the preamplifier is of the order of 3 ns over the entire dynamic range and is below 50 ns when coupled with a 130-pF photodiode. We qualified the spectroscopic performance by acquiring spectra of a mixed nuclei \alpha source and of different \gamma sources (137Cs and 60Co) with a CsI(Tl) scintillator crystal 3.2~\text cm\times 3.2~\text cm\times 6~\text cm coupled with a 18~\text mm\times 18~\text mm silicon p-i-n diode 300- \mu \textm -thick readout by the developed ASIC. [ABSTRACT FROM AUTHOR]

In this paper, the capabilities of a wide-area gamma ray photosensor based on a SiPM array are investigated. For this purpose, we have mounted an array of 144 (12\times12) SiPMs with individual active area of 3 \times 3~\mm^2 and a pitch of 4.2~\mm, thus covering an active area of 50.2 \times 50.2~\mm^2. The measurements were performed by coupling the SiPM array to LYSO crystal arrays of different pixel size (2\times2~\mm^2, 1.5 \times 1.5~\mm^2, and 1 \times 1~\mm^2) and 10–12 mm thicknesses. The SiPM array was controlled by means of three ASICs, and the SiPM signals were multiplexed in order to determine the gamma ray impact position by means of implementing the Anger logic algorithm in the ASIC. The optimum bias voltage and temperature dependence of the gamma ray sensor were determined. An energy resolution as good as 8%, for individual crystal pixels, were reached at 5 V overvoltage. The ASICs design allows one to “activate” different photosensor array areas. This feature has been used to evaluate the detector performance as a function of the crystal pixel size and the photosensor dark noise contribution. In this work we also show the system capability to provide depth-of-interaction (DOI) information by means of implementing a two-layer staggered approach. We have found that accurate DOI information is obtained when the ASICs enabled an SiPM active area as high as 32\times 32~\mm^2(8 \times 8 SiPMs). [ABSTRACT FROM PUBLISHER]

A novel CMOS integrated front-end architecture is presented throughout this paper. It is designed to be used with detectors based on continuous scintillation crystals plus position sensitive photomultiplier. Its structure aims at carrying out an analog computation which extracts fundamental information of the detected event. This fact allows us to avoid an individual acquisition of every input channel so that a large increase of inputs is feasible. In order to accomplish the processing task, a current buffer delivers a copy of each input signal to several computation blocks. Those processing units implement current mode analog filtering operations with a digitally programmable 8-bit precision coefficient for each front-end input. Output currents are summed and sent to the output stage where a buffered current output is provided. A voltage signal is also available by means of a rail-to-rail transresistance amplifier. The final goal is to obtain several moments of the light distribution on the detector surface. Each one provides useful information, such as energy, position, depth of interaction (from the light distribution width), skewness (deformation due to border effect), etc. Since the computation is purely additive, the current outputs can be used as inputs to other equal devices thus creating a fully expandable architecture. [ABSTRACT FROM PUBLISHER]