E. Nygard

First measurements with a diamond microstrip detector

Abstract We have constructed the first high resolution strip detector using chemical vapor deposited diamond as the detection medium. Devices produced with this material have the possibility of being extremely radiation hard with direct applications at high luminosity colliders. This paper details the detector material, the low noise readout electronics and the detector module. First results from a test with high momentum charged particles in a testbeam at CERN are described. We achieved a signal-to-noise of 6:1 and an efficiency of 85% for minimum ionizing particles in the testbeam. The detector has a strip pitch of 100 μm and a strip width of 50 μm. The measured position resolution we achieved was σ = 26 μm. Future development of diamond detectors with application in particle physics experiments and other fields is discussed.

Measurements of transistors and silicon microstrip detector readout circuits in the Harris AVLSIRA rad-hard CMOS process

Abstract The RD20 collaboration has been developing silicon detectors and front end electronics for inner tracking applications at the proposed Large Hadron Collider (LHC) accelerator at CERN. Prototype amplifier circuits and test structures have been designed and fabricated in a radiation hard bulk CMOS technology (Harris AVLSIRA). Results from measurements of individual transistors and circuits from the first fabrication run in this process are presented, before and after irradiation. The noise performance of the prototype amplifiers is compared with predictions from the transistor noise spectrum measurements, and the optimised performance is predicted.

Double-sided silicon microstrip detectors and low noise self-triggering multichannel readout chips for imaging applications

Abstract Double-sided silicon microstrip detectors and CMOS low noise self-triggering 16-channel chips have successfully been tested with low energy X-rays and β-emitting sources for imaging of simple patterns. The noise slope of the chip is measured to 19.2 e − /pF. Also a 2 × 2 mm 2 diode has been used to measure the photon energy resolution in the range of 8–60 keV. With the diode the K-line from Cu (8.04 keV) is clearly visible. Two-dimensional images are shown.

Measurements of a radiation hardened process: Harris AVLSIRA

Abstract The Harris AVLSIRA process is a bulk CMOS process that has been specifically developed for use in radiation environments. It is being studied in order to assess its suitability for use in the readout electronics that are being developed for proposed future large hadronic colliders. Initial studies from one processing batch are presented.

Radiation hard electronics for LHC

Abstract A CMOS front end electronics chain is being developed by the RD20 collaboration for microstrip detector readout at LHC. It is based on a preamplifier and CR-RC filter, analogue pipeline and an analogue signal processor. Amplifiers and transistor test structures have been constructed and evaluated in detail using a Harris 1.2 μm radiation hardened CMOS process. Progress with larger scale elements, including 32 channel front end chips, is described. A radiation hard 128 channel chip, with a 40 MHz analogue multiplexer, is to be submitted for fabrication in July 1994 which will form the basis of the readout of the tracking system of the CMS experiment.

ATLAS beam test results

Abstract Many different configurations of electronics and semiconductor strip detectors were studied in 1995 using the ATLAS tracking detector test area at the H8 beam-line of the CERN SPS. A significant fraction of these investigations are presented elsewhere in this volume and this paper will concentrate on the results with silicon strip detectors read out with electronics preserving the pulse height information. Data has been collected with the ADAM, APV5 and FElix read-out chips on a number of different detectors. The first results are presented for read out with LHC electronics of detectors to the ATLAS-A specification of 112.5 μm pitch, employing n-strips in n-type silicon, capacitive coupling and intermediate strips. It is demonstrated that with adequate signal/noise, a spatial resolution of ⋍13 μm is attainable with these detectors.

A new 2-dimensional high resolution Si detector for β- and γ-radiography

Abstract A double-sided silicon microstrip detector read out by a CMOS low noise self-triggering 128-channel chip has successfully been tested with low energy γ- and X-rays and β-emitting sources for imaging of simple patterns. The readout chip is described in detail, as well as the detector, the ancillary electronics and the data acquisition. Images of the size of 6.4 × 6.4 mm 2 are presented. The readout pitch is 50 μm in both the x - and the y -direction. The energy resolution for the 44.23 keV K α -line from Tb is measured to 0.86 keV (240 e − rms). For β-patterns with 35 S, the spatial spread shows a good correlation with the range of the particles (130 μm).

A new design of a low noise, low power consumption CMOS charge amplifier

Abstract In this paper, a new design of a low noise, low power consumption charge amplifier is described. Theoretical results show that an ENC (Input-referred Equivalent Noise Charge) reduction of 258 electrons for a detector capacitor C D of 10 pF has been obtained with regard to a conventional charge amplifier. A complete readout system including the proposed charge amplifier followed by a shaper amplifier has been realized in a 1.2 μm CMOS N-well process. The noise performance of 112 electrons at 0 pF with a slope of 34 electrons/pF for a shaping time of 200 ns and 1 mW power consumption has been obtained.

Radiation effects on the Viking-2 preamplifier-readout chip

Abstract We have studied the radiation sensitivity of the Viking-2 VLSI circuit which has been designed for the readout of silicon strip detectors and manufactured at Mietec in 1.5 μm CMOS technology. Both biased and unbiased chips have been irradiated with a 137Cs γ source up to a total dose of 2 kGy (200 krad) after which all tested chips were still fully functional. We report the characteristic changes of device parameters with dose, including equivalent noise charge for different capacitive loads, and determine transistor threshold shifts and change of mobilities.