373 research outputs found
CMOS Charge amplifier for liquid argon Time Projection Chamber detectors
We developed an integrated circuit (IC) for the readout of LAr (Liquid Argon) TPC (Time Projection Chamber) neutrino detectors. Typical signals are around 3 fC per particle per wire but they can go up to 120fC. They necessitate low noise electronics for the readout. The goal is to achieve 1000e- ENC (Equivalent Noise Charge) with a detector capacitance of 250pF. In order to limit cable capacitances (and therefore the noise), we studied the possibility to install the frontend electronics into the Argon vapours, above the LAr filled volume. Argon is liquid between 83 K and 87 K. A typical temperature around 120K is reached in the Argon vapours. In order to optimize the cost per channel ratio we selected a standard 0.35ÎĽ CMOS technology: AMSC35B4
The 8 bits 100 MS/s Pipeline ADC for the INNOTEP Project – TWEPP-09
This paper describes the Analog to Digital Converter developed for the front end electronic of the IN2P3 INNOTEP project by the “pole microelectronique Rhone-Auvergne”. (Collaboration between LPC Clermont-Ferrand and IPNL Lyon). This ADC is a 4 stages 2.5 bits per stage pipe line with open loops track and holds and amplifiers. It runs at 100MSamples/s and has 8 bits resolution. The stages used two lines, the gain line and the comparison line, with most operators running in current. The main idea of this current line is to make a first step toward an all in current structure. Currently, this ADC is designed with a 0,35μm SiGe technology
Front-end multi-channel PMT-associated readout chip for hodoscope application
International audienceThe system development requires a dedicated multi-channel readout ASIC (Application Specific Integrated Circuit) to be associated with the MaPMTs. Each channel should have very low input impedance to avoid electrical crosstalk between adjacent channels and to minimize effects of detector and wiring capacitances (Cd + Cw). Crosstalk between channels may degrade position resolution, while these capacitances may degrade both frequency and noise performances. Each channel should also provide two separated outputs corresponding respectively to high-speed signal-event detection and low-noise signal-charge quantification at low counting rate. This paper presents a readout chip for this purpose. It has been designed in a 0.35µm SiGe BiCMOS process (AMS). This process allows the use of RF and large-transconductance bipolar components, which is useful for the design of wide-band, low-impedance and low-noise circuits with improved performances
Pure Luminosity Evolution Hypothesis for QSOs: From Luminosity Functions to Synthetic Catalogues
This paper describes the simulation of realistic Monte-Carlo extragalactic
catalogues, aimed at comparing the behaviour of cosmological tests versus input
parameters. QSO catalogues are built on a Luminosity Function derived from data
through suitable computation of individual maximum volumes in complete (but
magnitude- and redshift-limited) samples requiring neither of redshift nor of
apparent magnitude histogram. The values of the evolution parameter are derived
for various cosmologies, corresponding to =1/2 in the sample of 400
Ultra-Violet Excess (UVX) QSOs (Boyle et al 1990). The various luminosity
functions are compared, both for the whole sample and in redshift bins. An
evolution characteristic time is defined and computed, depending strongly on
the cosmology, but practically constant when expressed in terms of the age of
the Universe. Algorithms are given for producing unbiased or biased catalogues
based on the null hypothesis that the objects are uniformly distributed in
volume but suffer Pure Luminosity Evolution.Comment: uuencode compressed tar file of Latex and macros files. Tar
compressed poscript files of the papers and figures are also available by
anonymous ftp at ftp://summer.obs-mip.fr/pub/OUTGOING/paper2 or upon request
at [email protected]
Light-to-light readout system of the CMS electromagnetic calorimeter
For the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN, an 80,000-crystal electromagnetic calorimeter will measure electron and photon energies with high precision over a dynamic range of roughly 16 bits. The readout electronics will be located directly behind the crystals, and must survive a total dose of up to 2Ă—104 Gy along with 5Ă—1013 n/cm 2. A readout chain consisting of a custom wide-range acquisition circuit, commercial ADC and custom optical link for each crystal is presently under construction. An overview of the design is presented, with emphasis on the large-scale fiber communication syste
A Low Noise and High Dynamic Charge Sensitive Amplifier-Shaper associated with Silicon Strip Detector for Compton Camera in hadrontherapy
submitted to conference record of IEEE NSS-MIC, Anaheim USA, 29 october-3 november 2012International audienceA 8 channel Front End Electronics (FEE) circuit has been designed and fabricated in 0.35 ÎĽm CMOS process from Austria Micro System to be coupled with the Silicon Strip Detector (SSD) of the Compton Camera for quality control of hadrontherapy. Each channel includes a Charge Sensitive Amplifier (CSA) followed by two parallel CR-RC shapers. Slow and fast shapers, with 1 ÎĽs and 15 ns shaping time, are used to measure the energy and to time stamp all events respectively. The two sides of the SSD are read thanks to a configurable system for holes and electrons. The CSA presents an open loop gain of 67 dB and 90 degrees phase margin assuring a high stability. The circuit has been successfully tested. The test results are in good agreement with analytic and simulation calculations. Here, we describe the principles and present measured performances of the prototype. A high linearity over the range of 3E3 to 3E6 electrons is reached with a conversion gain of 3.6 mV/fC. The circuit achieves an ENC (Equivalent Noise Charge) of 412 electrons rms. 75% of the total noise is generated by the small value of the feedback resistor chosen to avoid pile up phenomenon due to the 1E5 hits/s occupancy rate. A cross-talk of 2 % was measured, 99% of which is due to the power supply disturbances. The power supply dissipation is 21 mW/channel for 3.3 V supply voltage. The area of this design is 2871Ă—1881 ÎĽm2 including pads
A Charge-Sensitive Amplifier Associated with APD or PMT for Positron Emission Tomography Scanners
to be presented at the 32nd International Convention MIPRO (Microeectronics, Electronics, and Electronic Technology (MEET)), Opatija, Croatia, May 25-29 2009We present a Charge-Sensitive Amplifier (CSA) to be coupled with a 511-KeV 2-photon detector for positron emission tomography scanners. The circuit has been designed to be associated with an Avalanche Photodiode (APD) or Photo-Multiplier Tube (PMT) with large capacitance. It is a two-stage structure. The input stage consists of a foldedcascode fully-differential part and a common-mode feedback (CMFB) circuit. The output stage employs complementary source followers. The amplifier has been designed in a 0.35ÎĽm BiCMOS process with optimization of noise and speed performances to meet specific constraints. Its main characteristics evaluated by post-layout simulations are: 70-dB DC gain, 4.6-GHz GBW, 20-ns peaking time for pulsed stimulus, 3900-electron equivalent input noise charge (ENC), 135-mW power consumption at 3.5 V supply
Contribution of HEP electronics techniques to the medical imaging field
présenté par P.-E. Vert, proceedings sous forme de CD Imagerie Médical
Substructure lensing in galaxy clusters as a constraint on low-mass sterile neutrinos in tensor-vector-scalar theory: The straight arc of Abell 2390
Certain covariant theories of the modified Newtonian dynamics paradigm seem
to require an additional hot dark matter (HDM) component - in the form of
either heavy ordinary neutrinos or more recently light sterile neutrinos (SNs)
with a mass around 11eV - to be relieved of problems ranging from cosmological
scales down to intermediate ones relevant for galaxy clusters. Here we suggest
using gravitational lensing by galaxy clusters to test such a marriage of
neutrino HDM and modified gravity, adopting the framework of
tensor-vector-scalar theory (TeVeS). Unlike conventional cold dark matter
(CDM), such HDM is subject to strong phase-space constraints, which allows one
to check cluster lens models inferred within the modified framework for
consistency. Since the considered HDM particles cannot collapse into
arbitrarily dense clumps and only form structures well above the galactic
scale, systems which indicate the need for dark substructure are of particular
interest. As a first example, we study the cluster lens Abell 2390 and its
impressive straight arc with the help of numerical simulations. Based on our
results, we outline a general and systematic approach to model cluster lenses
in TeVeS which significantly reduces the calculation complexity. We further
consider a simple bimodal lens configuration, capable of producing the straight
arc, to demonstrate our approach. We find that such a model is marginally
consistent with the hypothesis of 11eV SNs. Future work including more detailed
and realistic lens models may further constrain the necessary SN distribution
and help to conclusively assess this point. Cluster lenses could therefore
provide an interesting discriminator between CDM and such modified gravity
scenarios supplemented by SNs or other choices of HDM.Comment: 22 pages, 14 figures, 2 tables; minor changes to match accepted
versio
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