M. Burns

Properties of a Fine Sampling Uranium - Copper Scintillator Hadron Calorimeter

Abstract We present results obtained with a uranium/copper scintillator fine-sampling calorimeter with wavelength shifter readout. Test beam measurements made with e±, π± and protons in the momentum range 0.3–40 GeV/c are presented. The calorimeter achieves energy resolutions of σ(E) E = 0.36 √E and 0.16 √E for hadrons and electrons, respectively. The measured ratio of response for electrons to that for hadrons is 1.11, for energies of 2 GeV or more. The spatial resolution achieved for single particles at normal incidence is ∼1 cm for electromagnetic showers and ∼3 cm for hadronic showers. Operational experience over three years of running at the CERN ISR, including operation at very high luminosities (∼1.4×1032 cm−2 s−1) is described.

Pixel readout chips in deep submicron CMOS for ALICE and LHCb tolerant to 10 Mrad and beyond

The ALICE1LHCB chip is a mixed-mode integrated circuit designed to read out silicon pixel detectors for two different applications: particle tracking in the ALICE Silicon Pixel Detector and particle identification in the LHCb Ring Imaging Cherenkov detector. To satisfy the different needs for these two experiments, the chip can be operated in two different modes. In tracking mode all the 50 μm×425 μm pixel cells in the 256×32 array are read out individually, whilst in particle identification mode they are combined in groups of 8 to form a 32×32 array of 400 μm×425 μm cells. Radiation tolerance was enhanced through special circuit layout. Sensitivity to coupling of digital signals into the analog front end was minimized. System issues such as testability and uniformity further constrained the design. The circuit is currently being manufactured in a commercial 0.25 μm CMOS technology.

First results from the ALICE silicon pixel detector prototype

Abstract System prototyping of the ALICE silicon pixel detector (SPD) is well underway. The ALICE SPD consists of two barrel layers with 9.83 million channels in total. These are read out by the ALICE1LHCb pixel chip, which has been developed in a commercial 0.25 μm process with radiation hardening by design layout. The readout chip contains 8192 pixel cells each with a fast analog preamplifier and shaper followed by a discriminator and digital delay lines. Test results show a pixel cell noise of about 110 electrons rms and a mean minimum threshold of about 1000 electrons rms before threshold fine tuning. Several readout chips have been flip-chip bonded to detectors using two different bump-bonding techniques (solder, indium). Results of radioactive source measurements of these assemblies are presented for 90 Sr and 55 Fe sources. Several chip-detector assemblies have been tested in a 150 GeV / c pion beam at CERN where an online efficiency of about 99% across a wide range of detector bias and threshold settings was observed. All preliminary investigations confirm the functionality of the chip and the chip-detector assemblies for the ALICE experiment.

THE NEW ALEPH SILICON VERTEX DETECTOR

The ALEPH collaboration, in view of the importance of effective vertex detection for the Higgs boson search at LEP 2, decided to upgrade the previous vertex detector. Main changes were an increased length (+/- 20 cm), a higher granularity for r phi view (50 mu m), a new preamplifier (MX7 rad hard chip), a polymide (upilex) fan-out on z side to carry the signals from the strips to the front-end electronics outside the fiducial region reducing consequently the passive material in the central region by a factor of two. The detector, the running experience and its performance will be described

The Alice silicon pixel detector

CERN European Organization for Nuclear Research, CH-1211 Geneva 23, Switzerland Universita degli Studi di Padova, I-35131, Padova, Italy Dipartimento IA di Fisica e Sez. INFN di Bari, I-70126,Bari,Italy Comenius University, SK-84215 Bratislava, Slovakia NIKHEF, National Institute for Nuclear Physics and High Energy Physics, 1098 SJ Amsterdam, The Netherlands Slovak Academy of Sciences, SK-04353, Kosice, Slovakia Universita di Roma I, La Sapienza, I-00185, Roma, Italy

Progress in the construction of the delphi microvertex detector

Abstract The design and progress in the construction of the DELPHI microvertex detector are presented. The layout is described, together with results on precision mounting of silicon detectors. The development of ac-coupled silicon microstrip detectors was an important contribution to the design. The use of low-power CMOS readout chips facilitates the cooling of the detector. A description of the fourth-generation readout processor for silicon strip detectors, the SIROCCO IV, implemented in FASTBUS, is given. Finally, two complementary systems for in-situ position monitoring of the detectors are described.

The ALICE on-Detector pixel PILOT system-OPS

The on-detector electronics of the ALICE silicon pixel detector (nearly 10 million pixels) consists of 1,200 readout chips, bump-bonded to silicon sensors and mounted on the front-end bus, and of 120 control (PILOT) chips, mounted on a multi chip module (MCM) together with opto-electronic transceivers. The environment of the pixel detector is such that radiation tolerant components are required. The front-end chips are all ASICs designed in a commercial 0.25-micron CMOS technology using radiation hardening layout techniques. An 800 Mbit/s Glink-compatible serializer and laser diode driver, also designed in the same 0.25 micron process, is used to transmit data over an optical fibre to the control room where the actual data processing and event building are performed. We describe the system and report on the status of the PILOT system.

The ALICE Silicon Pixel Detector: readiness for the first proton beam

The Silicon Pixel Detector (SPD) is the innermost element of the ALICE Inner Tracking System (ITS). The SPD consists of two barrel layers of hybrid silicon pixels surrounding the beam pipe with a total of ≈ 107 pixel cells. The SPD features a very low material budget, a 99.9% efficient bidimensional digital response, a 12 μm spatial precision in the bending plane (r) and a prompt signal as input to the L0 trigger. The SPD commissioning in the ALICE experimental area is well advanced and it includes calibration runs with internal pulse and cosmic ray runs. In this contribution the commissioning of the SPD is reviewed and the first results from runs with cosmic rays and circulating proton beams are presented.

Irradiation and SPS Beam Tests of the Alice1LHCb Pixel Chip

The Alice1LHCb front-end chip [1,2] has been designed for the ALICE pixel and the LHCb RICH detectors. It is fabricated in a commercial 0.25 μm CMOS technology, with special design techniques to obtain radiation tolerance. The chip has been irradiated with low energy protons and heavy ions, to determine the cross-section for Single Event Upsets (SEU), and with X-rays to evaluate the sensitivity to total ionising dose. We report the results of those measurements. We also report preliminary results of measurements done with 150 GeV pions at the CERN SPS.

The ALICE Pixel Detector Readout Chip Test System

The ALICE experiment will require some 1200 Readout Chips for the construction of the Silicon Pixel Detector [1] and it has been estimated that approximately 3000 units will require testing. This paper describes the system that was developed for this task.