PARISROC, a Photomultiplier Array Integrated Read Out Chip

PARISROC is a complete read out chip, in AMS SiGe 0.35 !m technology, for photomultipliers array. It allows triggerless acquisition for next generation neutrino experiments and it belongs to an R&D program funded by the French national agency for research (ANR) called PMm2: ?Innovative electronics for photodetectors array used in High Energy Physics and Astroparticles? (ref.ANR-06-BLAN-0186). The ASIC (Application Specific Integrated Circuit) integrates 16 independent and auto triggered channels with variable gain and provides charge and time measurement by a Wilkinson ADC (Analog to Digital Converter) and a 24-bit Counter. The charge measurement should be performed from 1 up to 300 photo- electrons (p.e.) with a good linearity. The time measurement allowed to a coarse time with a 24-bit counter at 10 MHz and a fine time on a 100ns ramp to achieve a resolution of 1 ns. The ASIC sends out only the relevant data through network cables to the central data storage. This paper describes the front-end electronics ASIC called PARISROC.Comment: IEEE Nuclear Science Symposium an Medical Imaging Conference (2009 NSS/MIC

A Characterization of Bispecial Sturmian Words

A finite Sturmian word w over the alphabet {a,b} is left special (resp. right special) if aw and bw (resp. wa and wb) are both Sturmian words. A bispecial Sturmian word is a Sturmian word that is both left and right special. We show as a main result that bispecial Sturmian words are exactly the maximal internal factors of Christoffel words, that are words coding the digital approximations of segments in the Euclidean plane. This result is an extension of the known relation between central words and primitive Christoffel words. Our characterization allows us to give an enumerative formula for bispecial Sturmian words. We also investigate the minimal forbidden words for the set of Sturmian words.Comment: Accepted to MFCS 201

Digital part of SiPM Integrated Read-Out Chip ASIC for ILC hadronic calorimeter

SPIROC is the Silicium Photo-multiplier (SiPM) Integrated Read-Out Chip designed for the future ILC hadronic calorimeter. It reads 36 SiPMs and has an autotrigger on its 36 channels. Its main requirements are a 100% trigger rate for signal over 1/2 photoelectron, a charge measurement up to 2000 photoelectrons and a time measurement with an accuracy better than 1ns. In order to perform all these functions, SPIROC integrates a complex digital part to manage all the different steps of normal working (acquisition, measure and read-out). This ASIC was submitted in June 2007 (technology AMS SiGe 0.35μm). In this paper, section I describes the general architecture of the ASIC and the main interactions between analogue and digital parts. Section II is dedicated to the different module of the digital part that manages the ASIC

SPIROC (SiPM Integrated Read-Out Chip): Dedicated very front-end electronics for an ILC prototype hadronic calorimeter with SiPM read-out

The SPIROC chip is a dedicated very front-end electronics for an ILC prototype hadronic calorimeter with Silicon photomultiplier (or MPPC) readout. This ASIC is due to equip a 10,000-channel demonstrator in 2009. SPIROC is an evolution of FLC_SiPM used for the ILC AHCAL physics prototype [1]. SPIROC was submitted in June 2007 and will be tested in September 2007. It embeds cutting edge features that fulfil ILC final detector requirements. It has been realized in 0.35m SiGe technology. It has been developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of readout channels needed. SPIROC is an auto-triggered, bi-gain, 36-channel ASIC which allows to measure on each channel the charge from one photoelectron to 2000 and the time with a 100ps accurate TDC. An analogue memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. A 12-bit Wilkinson ADC has been embedded to digitize the analogue memory content (time and charge on 2 gains). The data are then stored in a 4kbytes RAM. A very complex digital part has been integrated to manage all theses features and to transfer the data to the DAQ which is described on [2]

SPIROC (SiPM Integrated Read-Out Chip): Dedicated very front-end electronics for an ILC prototype hadronic calorimeter with SiPM read-out

The SPIROC chip is a dedicated very front-end electronics for an ILC prototype hadronic calorimeter with Silicon photomultiplier (or MPPC) readout. This ASIC is due to equip a 10,000-channel demonstrator in 2009. SPIROC is an evolution of FLC_SiPM used for the ILC AHCAL physics prototype [1]. SPIROC was submitted in June 2007 and will be tested in September 2007. It embeds cutting edge features that fulfil ILC final detector requirements. It has been realized in 0.35m SiGe technology. It has been developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of readout channels needed. SPIROC is an auto-triggered, bi-gain, 36-channel ASIC which allows to measure on each channel the charge from one photoelectron to 2000 and the time with a 100ps accurate TDC. An analogue memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. A 12-bit Wilkinson ADC has been embedded to digitize the analogue memory content (time and charge on 2 gains). The data are then stored in a 4kbytes RAM. A very complex digital part has been integrated to manage all theses features and to transfer the data to the DAQ which is described on [2]. After an exhaustive description, the extensive measurement results of that new front-end chip will be presented

SPIROC (SiPM Integrated Read-Out Chip): Dedicated very front-end electronics for an ILC prototype hadronic calorimeter with SiPM read-out.

Omega et Calice collaborationsInternational audienceThe SPIROC chip is a dedicated very front-end electronics for an ILC prototype hadronic calorimeter with Silicon photomultiplier (or MPPC) readout. This ASIC is due to equip a 10,000-channel demonstrator in 2009. SPIROC is an evolution of FLC_SiPM used for the ILC AHCAL physics prototype [1]. SPIROC was submitted in June 2007 and will be tested in September 2007. It embeds cutting edge features that fulfil ILC final detector requirements. It has been realized in 0.35m SiGe technology. It has been developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of readout channels needed. SPIROC is an auto-triggered, bi-gain, 36-channel ASIC which allows to measure on each channel the charge from one photoelectron to 2000 and the time with a 100ps accurate TDC. An analogue memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. A 12-bit Wilkinson ADC has been embedded to digitize the analogue memory content (time and charge on 2 gains). The data are then stored in a 4kbytes RAM. A very complex digital part has been integrated to manage all theses features and to transfer the data to the DAQ which is described on [2]. After an exhaustive description, the extensive measurement results of that new front-end chip will be presented

Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter

A large prototype of 1.3m3 was designed and built as a demonstrator of the semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each unit is built of an active layer made of 1m2 Glass Resistive Plate Chamber(GRPC) detector placed inside a cassette whose walls are made of stainless steel. The cassette contains also the electronics used to read out the GRPC detector. The lateral granularity of the active layer is provided by the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a self-supporting mechanical structure built also of stainless steel plates which, with the cassettes walls, play the role of the absorber. The prototype was designed to be very compact and important efforts were made to minimize the number of services cables to optimize the efficiency of the Particle Flow Algorithm techniques to be used in the future ILC experiments. The different components of the SDHCAL prototype were studied individually and strict criteria were applied for the final selection of these components. Basic calibration procedures were performed after the prototype assembling. The prototype is the first of a series of new-generation detectors equipped with a power-pulsing mode intended to reduce the power consumption of this highly granular detector. A dedicated acquisition system was developed to deal with the output of more than 440000 electronics channels in both trigger and triggerless modes. After its completion in 2011, the prototype was commissioned using cosmic rays and particles beams at CERN.Comment: 49 pages, 41 figure

Feasibility of right-sided total extraperitoneal procedure for inguinal hernia repair after appendectomy: a prospective cohort study

Contains fulltext : 80682.pdf (publisher's version ) (Open Access)BACKGROUND: Totally extraperitoneal (TEP) endoscopic hernia surgery is increasingly popular since it is associated with little postoperative pain and with early return to work. Previous appendectomy may preclude preperitoneal dissection in patients with right-sided hernias. The feasibility of TEP surgery in these patients was the subject of the present study. METHODS: Between January 2005 and February 2007 all consecutive patients undergoing TEP surgery were included in a prospective cohort study. The study group consisted of patients with right-sided and bilateral hernias. Operative times, conversions, complication rates, and return to daily activities were recorded. Patients were divided into two groups according to previous appendectomy. RESULTS: A total of 462 patients with right-sided hernias underwent TEP surgery: 421 patients without previous abdominal surgery (group 1) and 41 patients with previous appendectomy (group 2). The conversion rate was significantly higher in group 2: four patients (10%) were converted to open Lichtenstein repair versus five (1%) in group 1 (p = 0.005). However, we found no significant differences in complication rate, operative time, and return to daily activities. CONCLUSIONS: A right-sided (or bilateral) TEP procedure may be performed safely in patients after previous appendectomy. Despite a higher conversion rate, the vast majority of patients can be operated endoscopically

Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter

We present a study of showers initiated by electrons, pions, kaons, and protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE scintillator-tungsten analogue hadronic calorimeter. The data were recorded at the CERN Super Proton Synchrotron in 2011. The analysis includes measurements of the calorimeter response to each particle type as well as measurements of the energy resolution and studies of the longitudinal and radial shower development for selected particles. The results are compared to Geant4 simulations (version 9.6.p02). In the study of the energy resolution we include previously published data with beam momenta from 1 GeV to 10 GeV recorded at the CERN Proton Synchrotron in 2010.Comment: 35 pages, 21 figures, 8 table

Pion and proton showers in the CALICE scintillator-steel analogue hadron calorimeter

Showers produced by positive hadrons in the highly granular CALICE scintillator-steel analogue hadron calorimeter were studied. The experimental data were collected at CERN and FNAL for single particles with initial momenta from 10 to 80 GeV/c. The calorimeter response and resolution and spatial characteristics of shower development for proton- and pion-induced showers for test beam data and simulations using Geant4 version 9.6 are compared.Comment: 26 pages, 16 figures, JINST style, changes in the author list, typos corrected, new section added, figures regrouped. Accepted for publication in JINS