Double-sided Silicon Microstrip Detectors Research Articles

Quality Assurance Test System for Assembly of STS Modules for the BM@N Experiment

The Silicon Tracking System (STS) of the BM@N experiment will be based on modules with Double-Sided microstrip Silicon Detectors (DSSD) which have been initially developed for the CBM experiment at FAIR. Each module consists of a DSSD, two front-end boards with 8 ASICs each, and a set of low-mass aluminum microcables. During the module assembly the microcables are tab-bonded to the sensor and readout ASICs. The module has 1024 channels on each side of the sensor. For the quality assurance of the ultrasonic bonding process a dedicated procedure based on the noise per channel measurements with a Pogo Pin test device was developed.

The Belle II silicon vertex detector assembly and mechanics

The Belle II experiment at the asymmetric SuperKEKB collider in Japan will operate at an instantaneous luminosity approximately 50 times greater than its predecessor (Belle). The central feature of the experiment is a vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is CP violation asymmetry in the decays of beauty and charm hadrons, which hinges on a precise charged-track vertex determination and low-momentum track measurement. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the final SVD modules.Finally, some results from the latest test-beam are reported.

Non-invasive characterization and quality assurance of silicon micro-strip detectors using pulsed infrared laser

The Compressed Baryonic Matter (CBM) experiment at FAIR is composed of 8 tracking stations consisting of roughly 1300 double sided silicon micro-strip detectors of 3 different dimensions. For the quality assurance of prototype micro-strip detectors a non-invasive detector charaterization is developed. The test system is using a pulsed infrared laser for charge injection and characterization, called Laser Test System (LTS). The system is aimed to develop a set of characterization procedures which are non-invasive (non-destructive) in nature and could be used for quality assurances of several silicon micro-strip detectors in an efficient, reliable and reproducible way. The procedures developed (as reported here) uses the LTS to scan sensors with a pulsed infra-red laser driven by step motor to determine the charge sharing in-between strips and to measure qualitative uniformity of the sensor response over the whole active area. The prototype detector modules which are tested with the LTS so far have 1024 strips with a pitch of 58 μm on each side. They are read-out using a self-triggering prototype read-out electronic ASIC called n-XYTER. The LTS is designed to measure sensor response in an automatized procedure at several thousand positions across the sensor with focused infra-red laser light (spot size ≈ 12 μm, wavelength = 1060 nm). The pulse with a duration of ≈ 10 ns and power ≈ 5 mW of the laser pulse is selected such, that the absorption of the laser light in the 300 μm thick silicon sensor produces ≈ 24000 electrons, which is similar to the charge created by minimum ionizing particles (MIP) in these sensors. The laser scans different prototype sensors and various non-invasive techniques to determine characteristics of the detector modules for the quality assurance is reported.

Belle II SVD ladder assembly procedure and electrical qualification

The Belle II experiment at the SuperKEKB asymmetric e+e− collider in Japan will operate at a luminosity approximately 50 times larger than its predecessor (Belle). At its heart lies a six-layer vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is time-dependent CP violation asymmetry, which hinges on a precise charged-track vertex determination. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision three dimensional coordinate measurements of the jigs used in assembly as well as of the final SVD modules.

Radiation tolerance studies of neutron irradiated double sided silicon microstrip detectors

Radiation tolerance studies were made on double-sided silicon microstrip detectors for the Silicon Tracking System of the Compressed Baryonic Matter experiment at FAIR. The prototype detectors from two different vendors were irradiated to twice the highest expected fluence (1×10141MeVneqcm−2) in the CBM experimental runs of several years. Test results from these prototype detectors both before and after irradiations have been discussed.

Cross-talk studies on FPCB of double-sided silicon micro-strip detector

Double-sided silicon micro-strip detector's parameters and a test method and the results of cross-talk of FPCB are given in this abstract. In addition, the value of our detector's readout signal has little relation to FPCB's cross-talk.

NIEL studies on of double-sided silicon micro-strip detector

The methods of silicon detector's NIEL are given in this abstract and it also shows the result of proton NIEL for silicon.

Total and Partial Fragmentation Cross-Section of 500 MeV/nucleon Carbon Ions on Different Target Materials

By using an experimental setup based on thin and thick double-sided microstrip silicon detectors, it has been possible to identify the fragmentation products due to the interaction of very high energy primary ions on different targets. Here we report total and partial cross-sections measured at GSI (Gesellschaft fur Schwerionenforschung), Darmstadt, for 500 MeV/n energy $^{12}C$ beam incident on water (in flasks), polyethylene, lucite, silicon carbide, graphite, aluminium, copper, iron, tin, tantalum and lead targets. The results are compared to the predictions of GEANT4 (v4.9.4) and FLUKA (v11.2) Monte Carlo simulation programs.

The Micro-Vertex-Detector for the P̄ANDA experiment

P̄ANDA is a fixed target experiment that will be carried out at the future FAIR facility. P̄ANDA will provide an excellent tool to address fundamental question in the field of hadronic physics, with a physic program that extends from the investigation of QCD (providing insight in the mechanisms of mass generation and confinement) to the test of fundamental symmetries.The Micro-Vertex-Detector located in the innermost part of the central tracking system will be composed by hybrid pixel and double-sided micro-strip silicon detectors. The Micro-Vertex-Detector will play an important role for the P̄ANDA physics goals. The possibility to reconstruct the secondary vertices and the applicability of a precise D meson tagging is essential for the spectroscopy in the open charm sector and the charmonium mass region. To this aim the Micro-Vertex-Detector features a spatial resolution better than 100μm, a time resolution better than 20ns, a limited material budget, and a high data rate capability in a triggerless environment. An overview of the Micro-Vertex-Detector related to the physics goals will be presented.

Exploring Various Isolation Techniques to Develop Low Noise, Radiation Hard Double-Sided Silicon Strip Detectors for the CBM Silicon Tracking System

This paper reports on the design optimization done for Double Sided silicon microStrip Detectors (DSSDs) to reduce the Equivalent Noise Charge (ENC) and to maximize the breakdown voltage and Charge Collection Efficiency. Various isolation techniques have been explored and a detailed comparison has been studied to optimize the detector performance. To evaluate the performance of the silicon detectors, a radiation damage model has been included. The neutron fluence is expected to be 2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> n <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eq</sub> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> per year for five years of expected CBM run with intermediate periods of warm maintenance, cold maintenance and shutdown. Transient simulations have been performed to estimate the charge collection performance of the irradiated detectors and simulations have been verified with experimental data.

Antihydrogen annihilation reconstruction with the ALPHA silicon detector

The ALPHA experiment has succeeded in trapping antihydrogen, a major milestone on the road to spectroscopic comparisons of antihydrogen with hydrogen. An annihilation vertex detector, which determines the time and position of antiproton annihilations, has been central to this achievement. This detector, an array of double-sided silicon microstrip detector modules arranged in three concentric cylindrical tiers, is sensitive to the passage of charged particles resulting from antiproton annihilation. This article describes the method used to reconstruct the annihilation location and to distinguish the annihilation signal from the cosmic ray background. Recent experimental results using this detector are outlined.

Noise Characterization of Double-Sided Silicon Microstrip Detectors With Punch-Through Biasing

We report on extensive noise measurements performed on double-sided, AC-coupled, punch-through biased silicon strip detectors. We used a single-channel acquisition chain, reading one strip per side, all other strips being kept grounded. The noise has been measured over a wide range of peaking times and leakage currents, allowing a careful determination of the various noise contributions. We determined the noise contribution of the punch-through mechanism and we observed, on different sensors, two unexpected noise terms, one related to the punch-through current and the other to the presence of resistive layers at the Si/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interface.

Study of frequency-dependent strip admittance in silicon microstrip detectors

We report on detailed interstrip admittance measurements performed on double-sided, AC-coupled and punch-through biased silicon microstrip detectors. The sensors chosen have been fabricated on very high resistivity substrates, which translates in very low depletion voltages, in the range 10–20 V. This, together with the absence of bias resistors, allows a careful study of the strip admittance components over a wide range of bias voltages and frequencies. In some instances, beyond total depletion the measured interstrip capacitance and dissipation factor exhibit a marked voltage and frequency dependence, linked to the presence of some resistive component. A simple lumped electrical model has been developed to explain the observed features and 3-D numerical simulations have been performed, supporting the interpretation of the phenomena. These features of the admittance have been found to be closely correlated with a non-standard noise term, exhibiting a peculiar frequency/time dependence, which adds in quadrature to the well known parallel and series noise sources.

A novel Si strip array to investigate reaction and decay mechanisms

The performance of a novel set-up of double-sided silicon micro-strip detectors (DSSD) developed for the GSI-R3B project (reaction studies with relativistic radioactive beams) is presented. The set-up was used in an experiment aimed at measuring the two-proton decay of 19Mg. This experiment required to record simultaneously protons and the residual nuclei with good position and energy resolution. Our experimental results show that both protons and heavy ions ranging from Z=2 up to Z=12 can be identified with good signal-to-noise ratio and high energy and spatial resolution. This allowed to reconstruct 2- and 3-particle vertices with high precision, opening the possibility to measure lifetimes of very short-lived nuclei and to obtain precise angular correlations of the outgoing particles. This detection system serves as a prototype for the R3B recoil detector, which will be composed of a two-layer Si strip tracker.

Production of ALICE microstrip detectors at ITC-irst

We report on the results from the production of 600 double-sided silicon microstrip detectors for the ALICE experiment. We present the fabrication process and some selected results from the electrical characterization of detectors and test structures. The large amount of experimental data allowed a statistically relevant analysis to be performed. The main technological aspects related to production yield optimization will also be addressed.

Spatial resolution of double-sided silicon microstrip detectors for the PAMELA apparatus

The PAMELA apparatus has been assembled and it is ready to be launched in a satellite mission to study mainly the antiparticle component of cosmic rays. In this paper, the performances obtained for the silicon microstrip detectors used in the magnetic spectrometer are presented. This subdetector reconstructs the curvature of a charged particle in the magnetic field produced by a permanent magnet and consequently determines momentum and charge sign, thanks to a very good accuracy in the position measurements (better than 3 μ m in the bending coordinate). A complete simulation of the silicon microstrip detectors has been developed in order to investigate in great detail the sensor's characteristics. Simulated events have been then compared with data gathered from minimum ionizing particle (MIP) beams during the last years in order to tune free parameters of the simulation. Finally some either widely used or original position finding algorithms, designed for such kind of detectors, have been applied to events with different incidence angles. As a result of the analysis, a method of impact point reconstruction can be chosen, depending on both the particle's incidence angle and the cluster multiplicity, so as to maximize the capability of the spectrometer in antiparticle tagging.

Radiation damage studies for the B aB ar Silicon Vertex Tracker

The Silicon Vertex Tracker of the B aB ar experiment is a five-layer, double-sided AC-coupled silicon microstrip detector operating on the PEP-II storage ring at the Stanford Linear Accelerator Center. After more than four years of running, the silicon sensors and the front-end electronics in the inner layer have absorbed radiation doses up to 2 Mrad. In this paper we present results from radiation hardness tests and discuss the implications of the absorbed radiation dose on the Silicon Vertex Tracker lifetime.

The PAMELA silicon tracker

The silicon tracker of the PAMELA apparatus has been assembled and it is ready to fly on-board the Russian satellite Resurs DK for a 3-year mission. The experiment will study, mainly, spectra of particles and antiparticles in cosmic rays. The magnetic spectrometer's primary goal is to precisely measure momenta of charged particles, whose trajectories have been bent by a permanent magnet. The detector is composed of 6 planes of double-sided silicon microstrip detectors, inserted between adjacent modules of a permanent magnet which produces an almost uniform magnetic field inside a rectangular cavity that particles cross. The spatial resolution of the detectors is about 3 μm for the bending coordinate. The development of such detectors required a complex manufacturing procedure in order to preserve the physical performance in a device suitable for a space mission. In the construction phase data originating from both beam tests and simulation helped to check the detector's characteristics and to optimize the achievable spatial resolution. The development and the final assembling of these detectors are described in this paper.

PAMELA: a satellite experiment for antiparticles measurement in cosmic rays

PAMELA is a satellite-borne experiment that will study the antiproton and positron fluxes in cosmic rays in a wide range of energy (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and with high statistics, and that will measure the antihelium/helium ratio with a sensitivity of the order of 10/sup -8/. The detector will fly on-board a polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3-year-long mission. Particle identification and energy measurements are performed in the PAMELA apparatus using the following subdetectors: a magnetic spectrometer made up of a permanent magnet equipped with double-sided microstrip silicon detectors, an electromagnetic imaging calorimeter composed of layers of tungsten absorber and silicon detectors planes, a transition radiation detector made of straw tubes interleaved with carbon fiber radiators, a plastic scintillator time-of-flight and trigger system, a set of anticounter plastic scintillator detectors, and a neutron detector. The features of the detectors and the main results obtained in beam test sessions are presented.

Fabrication of AMS-02 microstrip detectors at ITC-irst

We report on selected results from the production of 400 double-sided silicon microstrip detectors for the AMS-02 experiment. The main process issues are discussed with emphasis on their impact on detector performance and fabrication yield.