Search results for "Semiconductor"
showing 10 items of 974 documents
Monte Carlo simulation of alpha spectra in low-geometry measurements
1994
Abstract Monte Carlo simulation of alpha spectra obtained with semiconductor detectors in low-geometry has been developed. The proposed method reproduces adequately experimental spectra of alpha emitters by taking into account the energy losses and trajectory changes of alpha particles as consequences of their interactions in the source, backing and detector.
A digital approach for real time high-rate high-resolution radiation measurements
2014
Abstract Modern spectrometers are currently developed by using digital pulse processing (DPP) systems, showing several advantages over traditional analog electronics. The aim of this work is to present digital strategies, in a time domain, for the development of real time high-rate high-resolution spectrometers. We propose a digital method, based on the single delay line (SDL) shaping technique, able to perform multi-parameter analysis with high performance even at high photon counting rates. A robust pulse shape and height analysis (PSHA), applied on single isolated time windows of the detector output waveforms, is presented. The potentialities of the proposed strategy are highlighted thro…
Der Zerfall des95Sr
1974
The nuclide95Sr was isolated by chemical separation methods after thermal neutron induced fission of235U. It's decay properties were investigated employing semiconductor spectrometers and coincidence techniques. A half-life of 24.4±0.2 sec was found. Out of 29 gamma rays, 25 transitions representing 97% of the observed gamma-ray intensity were placed in a decay scheme comprising 19 excited states of95Y.
Improving the Performance of Quasi-Hemispherical CdZnTe Detectors Using Infrared Stimulation
2012
The influence of monochromatic optical stimulation with wavelengths from 400 to 1100 nm on the characteristics of CdZnTe quasi-hemispherical detectors was studied. It was found that illumination with infrared (IR) light with wavelengths of 870-900 nm close to the absorption edge of the CdZnTe significantly improves the performance of the detector at room temperature. Improvement can be achieved with low-intensity IR illumination at 1-300 μW depending on the chosen wavelength of illumination. Higher intensity illumination was observed to lead to the degradation of the detector's spectrometric characteristics. IR radiation was noted to influence the detector's sensitivity, changing the equili…
Results of the 1999 H8 beam tests of ATLAS-SCT prototypes
2001
Abstract During the August–September 1999 test beam in H8 at CERN three half-modules, equipped with different types of fast binary Front End electronics, have been tested. The results indicate that all three SCT electronics candidates satisfy ATLAS efficiency and noise occupancy requirements. In addition, a study on the effect of detector bias voltage on efficiency (ballistic deficit) is reported.
A comparison of the performance of irradiated p-in-n and n-in-n silicon microstrip detectors read out with fast binary electronics
2000
Abstract Both n-strip on n-bulk and p-strip on n-bulk silicon microstrip detectors have been irradiated at the CERN PS to a fluence of 3×10 14 p cm −2 and their post-irradiation performance compared using fast binary readout electronics. Results are presented for test beam measurements of the efficiency and resolution as a function of bias voltage made at the CERN SPS, and for noise measurements giving detector strip quality. The detectors come from four different manufacturers and were made as prototypes for the SemiConductor Tracker of the ATLAS experiment at the CERN LHC.
Recent results from the ATLAS SCT irradiation programme
2000
Abstract The irradiation facility at the CERN proton synchrotron, set up to irradiate full-size prototypes of silicon microstrip detectors for the ATLAS semiconductor tracker, is described and measurements of the detector currents during irradiation are reported. The detector dark currents can be described by bulk radiation damage models demonstrating the radiation hardness of the detector design and allowing the current damage factor α and the acceptor introduction term β to be determined. Results from testbeam studies of a module with an irradiated detector and binary readout in a magnetic field and with the beam incident over a range of angles are reported. The hit efficiency and spatial…
Silicon microstrip detectors for the ATLAS SCT
2002
Abstract The ATLAS Semiconductor Tracker at the Large Hadron Collider (LHC) will incorporate ∼20,000 individual silicon microstrip sensors representing ∼60 m 2 of silicon. Production and delivery of the sensors is already underway and scheduled for completion by late 2002. The sensors have been optimised for operation in the harsh radiation environment of the LHC, and subjected to an extensive qualification program in which their pre- and post-irradiation characteristics have been evaluated. The sensor design features are reviewed, together with their electrical characteristics and the Quality Control procedures adopted by ATLAS during production.
Alignment of the NOMAD-STAR detector
2000
Abstract This note describes the alignment of the NOMAD-STAR detector. This is the B 4 C-silicon target installed in the NOMAD spectrometer in 1997. NOMAD-STAR is composed of modules of 12 silicon detectors each giving a total length of 72 cm. Ten of these modules (called ladders) are assembled to form a layer. There are five layers interleaved with passive boron carbide plates. The total surface of silicon is 1.14 m 2 . Energetic muons from the flat-top of the CERN SPS cycle provide the necessary information to perform a very precise software alignment. This alignment is needed to ensure that the impact parameter measurement needed for the identification of taus in a detector like NOMAD-ST…
Kalman filter tracking and vertexing in a silicon detector for neutrino physics
2002
Abstract This article describes the application of Kalman filter techniques for the tracking and vertexing of particles inside the NOMAD-STAR detector, a silicon vertex detector installed in NOMAD, one of the neutrino oscillation experiments at the CERN-SPS. The use of the Kalman filter simplifies computationally the tracking and vertex procedure for NOMAD-STAR. The alignment of NOMAD-STAR is shown as an example of the application of the Kalman filter for tracking purposes. The accuracy of the method is such that one obtains alignment residuals between 9 and 12 μm . Furthermore, a preliminary measure of the impact parameter (with an RMS ∼36 μm ) illustrates the vertexing capabilities of thi…