Crosstalk characteristics such as pulse amplitude and shape are studied with a simple PSpice model of the capacitive couplings within an MPGD. The crosstalk pulse shape can be understood as due to a CR-differentiator. Crosstalk can occur simultaneously through more than one capacitive coupling path. The crosstalk signals on these paths add differently if the signal is induced via a current source as in normal detector operation or via a voltage source as is often done in benchtop tests with an external voltage pulse generator. A few means for reducing the crosstalk are investigated with the model. It shows that a low-impedance AC path from the amplification electrode that faces the readout structure to ground is important for minimizing crosstalk. This implies a need for a sufficiently large capacitance of that amplification electrode to ground. This result has consequences for how much such an amplification electrode can be segmented without incurring crosstalk.
Electroluminescence produced during avalanche development in gaseous avalanche detectors is an useful information for triggering, calorimetry and tracking in gaseous detectors. Noble gases present high electroluminescence yields, emitting mainly in the VUV region. The photons can provide signal readout if appropriate photosensors are used. Micropattern gaseous detectors are good candidates for signal amplification in high background and/or low rate experiments due to their high electroluminescence yields and radiopurity. In this work, the VUV light responses of the Gas Electron Multiplier and …
This report summarizes the present knowledge on discharges in micropattern and small gap gaseous detectors and the physical mechanisms involved. These include the space-charge (Raether's) limit, rate-induced breakdown, cathode excitation effect and electron emission from the cathodes in the form of jets, inter-GEM breakdown in multistep configurations and finally surface streamers.
We have developed a cost effective technology for manufacturing various layouts of micropattern gaseous detectors for a wide range of applications. Such devices feature resistive electrodes interfaced to a network of thin readout strips/electrodes. The following three examples of such innovative designs and their applications will be presented: a prototype of a novel double-phase LAr detector with a CsI photocathode immersed inside the LAr, a CsI-RICH detector prototype for ALICE upgrade and GEM-like sensors for environmental safety/security applications.
We describe the most recent efforts made by various groups in implementing resistive electrodes in micropattern gaseous detectors with the aim to combine in the same design the best features of RPCs (for the example, their robustness and spark protection property) with the high granularity and thus the good position resolution offered by microelectronic technology. In the stream of this activity, we have recently developed two novel detectors with resistive electrodes: one was based on resistive micromeshes and the second one is a MSGC with resistive electrodes. We have demonstrated that the r…
Nowadays RPCs are in a booming phase: they are successfully used in many experiments, including LHC; there are ambitious plans to use them in several upgrade detectors and in some new experiments as well as in various applications. The aim of this paper is to highlight the main challenges which the RPC community may face in the next few years and which were addressed in talks presented at this conference. Examples could be: new and difficult requirements from experiments (and their upgrades) and applications, optimization and improvements of the existing traditional detector designs, improveme…
The RD51 collaboration was founded in April 2008 to coordinate and facilitate efforts for development of micropattern gaseous detectors (MPGDs). The 75 institutes from 25 countries bundle their effort, experience and resources to develop these emerging micropattern technologies. MPGDs are already employed in several nuclear and high-energy physics experiments, medical imaging instruments and photodetection applications; many more applications are foreseen. They outperform traditional wire chambers in terms of rate capability, time and position resolution, granularity, stability and radiation h…
The RD51 collaboration was founded in April 2008 to coordinate and facilitate efforts for development of micropattern gaseous detectors (MPGDs). The 59 institutes from 20 countries bundle their effort, experience and resources to develop these emerging micropattern technologies. MPGDs are already employed in several nuclear and high-energy physics experiments, medical imaging instruments and photodetection applications; many more applications are foreseen. They outperform traditional wire chambers in terms of rate capability, time and position resolution, granularity, stability and radiation h…
In recent years important progress in micropattern gaseous detectors has been achieved in the use of resistive material to build compact spark-protected devices. The novel idea presented here consists of the polarisation of WELL structures using only resistive coating. This allows a new device to be built with an architecture based on a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings. Each layer provides a signal wit…
The prospect of pileup induced backgrounds at the High Luminosity LHC (HL-LHC) has stimulated intense interest in technology for charged particle timing at high rates. In contrast to the role of timing for particle identification, which has driven incremental improvements in timing, the LHC timing challenge dictates a specific level of timing performance- roughly 20-30 picoseconds. Since the elapsed time for an LHC bunch crossing (with standard design book parameters) has an rms spread of 170 picoseconds, the $\sim50-100$ picosecond resolution now commonly achieved in TOF systems would be insu…
A new family of spark-protected micropattern gaseous detectors is introduced: a 2-D sensitive restive microstrip counter and hybrid detectors, which combine in one design a resistive GEM with a microstrip detector. These novel detectors have several important advantages over other conventional micropattern detectors and are unique for applications like the readout detectors for dual phase noble liquid TPCs and RICHs.
A muon tracking system consisting of four 9cm x 10cm sized bulk Micromegas detectors with 128um amplification-gap and two 10cm x 10cm triple GEM detectors is foreseen for high-precision tracking of 140GeV muons at the H8 beamline at CERN with a rate of up to 10kHz and an overall resolution below 40um. Larger detectors with an active area of 0.5m^2 and more are under development for detector studies in high neutron or gamma ray background environments at the Gamma Irradiation Facility at CERN and the Munich tandem accelerator. Signal studies of both detector types have been performed by recordi…
The LHC is undergoing a high luminosity upgrade, which is set to increase the instantaneous luminosity by at least a factor of five, resulting in a higher muon flux rate in the forward region, which will overwhelm the current trigger system of the CMS experiment. The ME0, a gas electron multiplier detector, is proposed for the Phase-2 Muon System Upgrade to help increase the muon acceptance and to control the Level 1 muon trigger rate. To lower the probability of HV discharges, the ME0 was designed with GEM foils that are segmented on both sides. Initial testing of the ME0 showed substantial c…
We describe here various detectors designs: GEM type, MICROMEGAStype, PPACtype as well as cascaded detectors made of a resistive mesh manufactured from a resistive Kapton foil, (20 microns thick, resistivity a few MOhm per square) by a laser drilling technique. As in any other micropattern detectors the maximum achievable gas gain of these detectors is restricted by the Raether limit, however, the resistive mesh makes them and the front end electronics fully spark protected. This approach could be an alternative or complimentary to the ongoing efforts in developing MICROMEGAS and GEMs with res…
In the last few years our group have focused on developing various designs of spark-protected micropattern gaseous detectors featuring resistive electrodes instead of the traditional metallic ones: resistive microstrip counters, resistive GEM, resistive MICROMEGAS. These detectors combine in one design the best features of RPCs (spark-protection) and micropattern detectors (a high position resolution). In this paper we report the progress so far made in developing other types of resistive micropattern detectors: a microdot-microhole detector and a microgap-microstrip detector. The former detec…
HxRG detectors have crosstalk between amplifier channels at a scientifically relevant level. In principle, crosstalk signals can be fully calibrated and removed from data, but only if a full crosstalk matrix is measured for the detector. We present a fast method of crosstalk characterization that can be performed with most instrument calibration units; it requires only a flat-field illumination and window programming in the HxRG detectors. We show the crosstalk matrices obtained with this method for both fast and slow mode in an H2RG detector, and give examples of how this data can be used to …
For the first time we have fabricated a high granularity micropattern solid-state detector (MSSD) with the unipolar time-differential property for ultrafast pulse response. Optical, x-ray, and gamma-ray photoconductivity measurements prove the unipolar time-differential response with a speed improvement factor of ~400 for amorphous selenium MSSD. The significance of the results presented here is the ability to reach the intrinsic physical limit for detector pulse speed by transitioning from the transit-time-limited response, which depends on the bulk carrier transport mechanism, to range-limit…
Deep learning tools are being used extensively in high energy physics and are becoming central in the reconstruction of neutrino interactions in particle detectors. In this work, we report on the performance of a graph neural network in assisting with particle flow event reconstruction. The three-dimensional reconstruction of particle tracks produced in neutrino interactions can be subject to ambiguities due to high multiplicity signatures in the detector or leakage of signal between neighboring active detector volumes. Graph neural networks potentially have the capability of identifying all t…
Multi-spectral quantitative phase imaging (QPI) is an emerging imaging modality for wavelength dependent studies of several biological and industrial specimens. Simultaneous multi-spectral QPI is generally performed with color CCD cameras. However, color CCD cameras are suffered from the color crosstalk issue, which needed to be explored. Here, we present a new approach for accurately measuring the color crosstalk of 2D area detectors, without needing prior information about camera specifications. Color crosstalk of two different cameras commonly used in QPI, single chip CCD (1-CCD) and three …
Aqua MODIS Moon images obtained with bands 20 to 26 (3.66 - 4.55 and 1.36 - 1.39 $μ$m) during scheduled lunar events show evidence of electronic crosstalk contamination of the response of detector 1. In this work, we determined the sending bands for each receiving band. We found that the contaminating signal originates, in all cases, from the detector 10 of the corresponding sending band and that the signals registered by the receiving and sending detectors are always read out in immediate sequence. We used the lunar images to derive the crosstalk coefficients, which were then applied in the c…
SILEM : a new gaseous detector with integrated x-y readout plane
本文报道了在EXO双β衰变实验框架内研制的气体探测器。LEM（Large Electron Multiplication）是基于GEM的电子放大栅极。它们是在纳沙泰尔开发的，对火花具有出色的抵抗力。新的SILEM网格将标准LEM的特性与网格一侧的微图案化x-y读出平面相结合。因此，它允许初级电子的放大和它们在x-y平面中的位置确定。
Aqua MODIS, unlike its predecessor on board the Terra spacecraft, had always been thought to have been spared from significant deleterious impacts of electronic crosstalk on its imagery. However, recent efforts brought to our attention the presence of striping artifacts in Aqua MODIS images from band 24 (4.47$μ$m), which upon further inspection proved to have a noticeable impact on the quality of the L1B product and to have been present since the beginning of the mission, in 2002. Using images of the Moon from scheduled lunar observations, we linked the artifacts with electronic crosstalk cont…
Photon detectors like the ALICE Calorimeters are vulnerable to both optical and electrical crosstalk between detector channels belonging to the same particle event. In order to quantify the crosstalk generated by a single channel on its neighbours, the standard method used so far are calibrated electrical pulses in order to quantify the crosstalk between individual frontend preamplifier channels. However due to grounding imperfections, cross-couplings via bias voltage supplies and imperfect electromagnetic shielding, this method introduces biases and is not precise. A new approach is the use o…
Micromegas detectors are a relatively modern design concept for micropattern gas detectors, designed to handle high particle flux while providing high gain, high spatial resolution, and fast response times for a variety of radiation detection applications. Due to the advancement of industry, building a micromegas detector without advanced in-house capabilities is now possible. In this work, we present an innovative method to build micromegas detectors utilizing precision manufacturers to fabricate the core components. Two detectors were built using the newly described method and are experiment…
This article reports on the development and experimental results of commercial plasma display panels adapted for their potential use as micropattern gas radiation detectors. The plasma panel sensors (PPS) design an materials include glass substrates, metal electrodes and inert gas mixtures which provide a physically robust, hermetically-sealed device. Plasma display panels used as detectors were tested with cosmic ray muons, beta rays and gamma rays, protons and thermal neutrons. The results demonstrated rise times and time resolution of a few nanoseconds, as well as sub-millimeter spatial res…
A software package for modeling segmented High-Purity Segmented Germanium detectors, AGATAGeFEM, is presented. The choices made for geometry implementation and the calculations of the electric and weighting fields are discussed. Models used for charge-carrier velocities are described. Numerical integration of the charge-carrier transport equation is explained. Impact of noise and crosstalk on the achieved position resolution in AGATA detectors are investigated. The results suggest that crosstalk as seen in the AGATA detectors is of minor importance for the position resolution. The sensitivity …
Precision Light Yield and Crosstalk Characterization for the SuperFGD scintillator cubes
Lebedev Physical Institute of the Russian Academy of Sciences（俄罗斯科学院列别杰夫物理研究所）；Institute for Nuclear Research of RAS（俄罗斯科学院核问题研究所）；Moscow Institute of Physics and Technology（莫斯科物理技术学院）；B.P. Konstantinov Petersburg Nuclear Physics Institute（B.P.康斯坦丁诺夫圣彼得堡核物理研究所）；National Research Center Kurchatov Institute（库尔恰托夫国家研究中心）；National Research Nuclear University MEPhI（国立核研究大学MEPhI）
We have developed microstrip gas counters manufactured on standard printed circuit board and having the following features: resistive cathode strips, thin (10 micron) metallic anode strips and electrodes protected against surface discharges by a Coverlay layer at their edges. These features allow the detector to operate at gas gains as high as can be achieve with the best microstrip gas counters manufactured on glass substrates. We believe that after further developments this type of detectors can compete in some applications with other micropattern detectors, for example MICROMEGAS.
The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels. It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in plasma display panels, it uses nonreactive, intrinsically radiation-hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low-mass detectors with gas gaps from a few hundred microns to a few millimeters. The P…
A First Mass Production of Gas Electron Multipliers
我们报告了使用3M的全自动卷对卷柔性电路生产线制造第一批约2，000个气体电子倍增器（GEM）的情况。该工艺允许低成本、可再现地制造尺寸高达30 $\times$ 30 cm $^{2}$的大量宝石。第一次测试表明，所得到的GEM具有作为辐射探测器的最佳性能。介绍了GEM的生产工艺和性能的初步测试。这一现已证明的工业能力应有助于进一步确立微图案气体探测器在基于加速器和非加速器的粒子物理学、成像和光电探测中的突出地位。
A radiation detector based on plasma display panel technology, which is the principal component of plasma television displays is presented. Plasma Panel Sensor (PPS) technology is a variant of micropattern gas radiation detectors. The PPS is conceived as an array of sealed plasma discharge gas cells which can be used for fast response (O(5ns) per pixel), high spatial resolution detection (pixel pitch can be less than 100 micrometer) of ionizing and minimum ionizing particles. The PPS is assembled from non-reactive, intrinsically radiation-hard materials: glass substrates, metal electrodes and …
The Microhexcavity Panel ( muHex) is a novel gaseous micropattern particle detector comprised of a dense array of close-packed hexagonal pixels, each operating as an independent detection unit for ionizing radiation. It is a second generation detector derived from plasma panel detectors and microcavity detectors. The muHex is under development to be deployed as a scalable, fast timing (ns) and hermetically sealed gaseous tracking detector with high rate ( > 100 KHz/cm^2 ) capability. The devices reported here were fabricated as 16 x 16 pixel arrays of 2 mm edge-to-edge, 1 mm deep hexagonal cel…
MicroPattern Gaseous Detectors (MPGD) made of resistive strips have raised as a promising technology for the protection against spark processes having place in the gaseous chamber. The reproduction of the signals and its propagation through the resistive foil is mandatory to better understand its behavior and optimize the key parameters which might depend on the application requirements. In this work it will be presented a resistive-strip model and the charge diffusion through the resistive strip for different model parameters, such as the strip linear resistivity and capacitance, together wit…
