FLC−SIPM: Front-End Chip for SIPM Readout for ILC Analog HCAL

eConf: C050318 : LCWS-2005-0916An integrated front-end chip has been developed to readout the Silicon PM for the ILC analog hadronic calorimeter. It is built around a variable gain low-noise preamplifier followed by a variable peaking-time shaper (20-200 ns), track and hold and multiplexed output. This structure allows to produce single photo electron spectrum with well separated peaks for absolute calibration at fast shaping (40ns) as well as physics signals from the scintillating fibbers (up to 2000 photo-electrons) with a slower shaping (150ns) compatible with the W-Si Electromagnetic Calorimeter DAQ. Besides, an input DAC allows to tune the detector gain by varying the operating voltage by up to 5V. The chip accommodates 18 channels and 1000 circuits have been produced in 2004, the design and the measurement results of which will be presented

A large dynamic range integrated front-end for photomultiplier tubes

A full custom analog CMOS circuit for obtaining a photomultiplier readout with a 16 bit resolution over 7 V has been developed. It is part of the R&D program for the photomultiplier tube front-end readout of the Pierre Auger Observatory northern site. It performs signal duplication and amplification with three gains: 0.15, 1 and 6. Each amplifier has a resolution of 10 bit and can measure signals with durations of several microseconds with a good baseline stability, for an input charge of up to tens of nano-Coulombs. The amplification is performed by current feedback amplifiers with a bandwidth of 60 MHz.The input impedance, adapted to the coaxial cables, is stable over the whole working range. A prototype was submitted in April 2004 and successfully tested. The linearity over the working range is less than 1%. It was also successfully tested on the Auger surface detector element installed at Orsay (comprised of a Cherenkov water tank equipped with Photonis XP1805 9” diameter photomultiplier tubes). The resolution over 7 V is 16.6 bit.This circuit is the first step towards a “system-on-a-chip” (SoC) solution for a photomultplier tube readout equipped with a fast ADC for signal digitization. A setup using a single cable for both the signal and the photomultiplier high voltage power supply was shown to be successful

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.

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

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

The OPERA experiment Target Tracker

The main task of the Target Tracker detector of the long baseline neutrino oscillation OPERA experiment is to locate in which of the target elementary constituents, the lead/emulsion bricks, the neutrino interactions have occurred and also to give calorimetric information about each event. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multi-anode photomultiplier tubes. All the elements used in the construction of this detector and its main characteristics are described.Comment: 25 pages, submitted to Nuclear Instrument and Method

Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation

We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including high signal-to-noise HST data, and spectra of six SNe Ia that were discovered during 2001 are presented. Additionally, for the two SNe with z>1, we present ground-based J-band photometry from Gemini and the VLT. These are among the most distant SNe Ia for which ground based near-IR observations have been obtained. We add these six SNe Ia together with other data sets that have recently become available in the literature to the Union compilation (Kowalski et al. 2008). We have made a number of refinements to the Union analysis chain, the most important ones being the refitting of all light curves with the SALT2 fitter and an improved handling of systematic errors. We call this new compilation, consisting of 557 supernovae, the Union2 compilation. The flat concordance LambdaCDM model remains an excellent fit to the Union2 data with the best fit constant equation of state parameter w=-0.997^{+0.050}_{-0.054} (stat) ^{+0.077}_{-0.082} (stat+sys\ together) for a flat universe, or w=-1.035^{+0.055}_{-0.059} (stat)^{+0.093}_{-0.097} (stat+sys together) with curvature. We also present improved constraints on w(z). While no significant change in w with redshift is detected, there is still considerable room for evolution in w. The strength of the constraints depend strongly on redshift. In particular, at z > 1, the existence and nature of dark energy are only weakly constrained by the data.Comment: 33 pages, 18 figures; accepted for publication in Astrophysical Journal. For data tables, code for cosmological analysis and full-resolution figures, see http://supernova.lbl.gov/Union

Observations of Mkn 421 in 2004 with H.E.S.S. at large zenith angles

Mkn 421 was observed during a high flux state for nine nights in April and May 2004 with the fully operational High Energy Stereoscopic System (H.E.S.S.) in Namibia. The observations were carried out at zenith angles of 60$^\circ$--65$^\circ$, which result in an average energy threshold of 1.5 TeV and a collection area reaching 2~km$^2$ at 10~TeV. Roughly 7000 photons from Mkn~421 were accumulated with an average gamma-ray rate of 8 photons/min. The overall significance of the detection exceeds 100 standard deviations. The light-curve of integrated fluxes above 2~TeV shows changes of the diurnal flux up to a factor of 4.3. For nights of high flux, intra-night variability is detected with a decay time of less than 1 hour. The time averaged energy spectrum is curved and is well described by a power-law with a photon index \egamm and an exponential cutoff at \ecut~TeV and an average integral flux above 2~TeV of 3 Crab flux units. Significant variations of the spectral shape are detected with a spectral hardening as the flux increases. Contemporaneous multi-wavelength observations at lower energies (X-rays and gamma-rays above $\approx 300$~GeV) indicate smaller relative variability amplitudes than seen above 2~TeV during high flux state observed in April 2004.Comment: 5 pages, 4 figures, published in A&