Single-sided Silicon Strip Detectors Research Articles

New beam position detectors for NA61/SHINE experiment

NA61/SHINE is a multi-purpose fixed-target experiment located at the Super Proton Synchrotron at CERN. The main goals of the experiment include studies for physics of strong interactions, neutrino physics, and cosmic-rays physics. After the upgrade of the detector system, the experiment will collect data up to 1 kHz event rate. The development of new detectors, used to measure the positions of incoming beam particles in the transverse plane, is a crucial part of the upgrade. Two new kinds of beam position detectors are prepared and tested. One of them is the scintillating fiber detector with a multi-anode photomultiplier readout. It is built of two perpendicularly arranged ribbons, each consisting of two shifted layers of green-emitting scintillating fibers with a diameter of 250 μm. The second type of detector is based on single-sided silicon strip detector (Hamamatsu S13804). The paper gives an overview of both detectors’ design and readout concepts.

Track recognition for the [formula omitted] telescopes with silicon strip detectors

For the high granularity and high energy resolution, Silicon Strip Detector (SSD) is widely applied in assembling telescopes to measure the charged particles in heavy ion reactions. In this paper, we present a novel method to achieve track recognition in the SSD telescopes of the Compact Spectrometer for Heavy Ion Experiment (CSHINE). Each telescope consists of a single-sided silicon strip detector (SSSSD) and a double-sided silicon strip detector (DSSSD) backed by 3 × 3 CsI(Tl) crystals. Detector calibration and track reconstruction are implemented. Special decoding algorithm is developed for the multi-track recognition procedure to deal with the multi-hit effect convoluted by charge sharing and the missing signals with certain probability. It is demonstrated that the track recognition efficiency of the method is approximately 90% and 80% for the DSSSD-CsI and SSSSD–DSSSD events, respectively.

A Compact Spectrometer for Heavy Ion Experiments in the Fermi energy regime

A Compact Spectrometer for Heavy IoN Experiments (CSHINE) has been recently built for the studies of heavy ion reactions at intermediate energies. CSHINE consists of a Si-Si-CsI telescope array and a parallel plate avalanche counter (PPAC) array. Each telescope consists of a thin single-sided silicon strip detector and a thick double-sided silicon strip detector backed by a 3 × 3 CsI(Tl) crystal hodoscope. The thicknesses of the silicon detectors are optimized in order to identify various types of light charged particles in a wide energy range. PPAC is a large-area two-dimensional position-sensitive gas detector, which records fission fragments with the intrinsic efficiency of approximately 100% but filters out light charged particles at properly selected working conditions. In the phase-II run, four Si-Si-CsI telescopes and three PPACs have been installed and operated in the beam experiment with 25 MeV/u Kr+Pb reactions. Particle identification for isotopes from Hydrogen to Boron has been achieved with the Si-Si-CsI telescopes, while excellent timing and position resolution have been achieved with the PPACs.

Investigation of the thickness non-uniformity of the very thin silicon-strip detectors

The properties of some very thin (∼20μm) large-area Single-sided Silicon-Strip Detectors (SSSDs) were investigated by using the 12C-particles elastically scattered from a Au target. In the detection system, each thin SSSD was installed in front of a thick (300 μm or 500 μm) Double-sided Silicon-Strip Detector (DSSD) to form a ΔE−E particle-telescope. The energy calibration of these detectors was realized by varying the beam energy and also by the irradiation from a three-component α-particle source. The thickness distribution each SSSD is precisely determined from the energy loss in the thin layer, which was independently measured by the corresponding DSSD. It is found that, for the SSSD with the nominal thicknesses of ∼20μm, the real thickness may vary by several μm over the active area. The reason for this large non-uniformity still needs to be investigated. For the present application, this non-uniformity could be corrected according to the known pixel-thickness. This correction allows to restore a good particle identification (PID) performance for the entire large-area detector, the importance of which is demonstrated by an example of measuring the cluster-decays of the highly-excited resonant states in 16O.

Study of the design optimization of AC-coupled single-sided silicon strip sensors

The high-intensity rare-isotope accelerator, RAON, will be constructed for nuclear physics research in Korea. AC-coupled single-sided silicon strip detectors (SSSDs) are being investigated for use in the Si-CsI detector of a large acceptance multi-purpose spectrometer to measure the energies of various isotopes. To determine the optimal design, four SSSD design parameters were examined in this study, namely the ratio of p+ implant width to strip pitch (I/P), the width of the metal layer, the presence of an n+-edge field shaper (FS), and the distance between the guard-ring and sensor edge (DGS). The designed detectors were fabricated on high resistivity n-type silicon wafers of 500 μm thickness. The SSSDs had the strip pitch of 730 μm and 32 readout strips in each, and the size of the sensors was 40.0 × 25.5 mm2. In terms of the leakage current and production yield, the noise improved by up to 30%when the I/P ratio was 0.4, the metal layer was wider than the p+ implantation, and the DGS with n+-edge FS was twice the sensor thickness. The signal-to-noise ratio of the SSSD with the design parameters that provided the optimal leakage current and coupling capacitance was measured to be 29.1 using a 90Sr radioactive source and commercial electronics.

Design and performance of the silicon strip tracker of the Fermi Large Area Telescope

The Large Area Telescope (LAT) is the primary instrument on-board the Fermi Gamma-ray Space Telescope (Fermi), an observatory on a low Earth orbit that was launched on 11 June 2008 to monitor the high energy γ-ray sky. The LAT tracker is a solid-state instrument: tungsten foils convert the gamma rays into electron-positron pairs which are then tracked in silicon planes in order to reconstruct the incoming photon direction. The tracker comprises 36 planes of single-sided silicon strip detectors, for a total of 73 square meters of silicon, read out by nearly 900,000 amplifier-discriminator channels. The system operates on only 160 W of conditioned power while achieving > 99% single-plane efficiency within its active area and better than 1 channel per million noise occupancy. We describe the tracker design and performance, and discuss in particular the excellent stability of the hardware response during the first three years of operation on orbit.

Geometrical optimization of a particle tracking system for proton computed tomography

Abstract Proton computed tomography (pCT) is currently being developed as an imaging modality for improving the accuracy of treatment planning in proton therapy. A tracking telescope comprising eight planes of single-sided silicon strip detectors (SSDs) forms an integral part of our present pCT design. Due to the currently maximum available Si wafer size, the sensitive area of 9 cm × 18 cm of the pCT tracker requires each tracking plane to be composed of two individual SSDs, which creates potential reconstruction problems due to overlap or gaps of the sensitive SSD areas. Furthermore, the spacing of the tracking planes creates competing design requirements between compactness and spatial resolution. Two Monte Carlo simulations were performed to study the effect of tracking detector location on pCT image quality. It was found that a “shingled” detector design suppressed reconstruction artefacts and, for the spatial resolution of the current detector hardware, reconstructed spatial resolution was not improved with a tracking separation of greater than 8 cm.

THE LARGE AREA TELESCOPE ON THEFERMI GAMMA-RAY SPACE TELESCOPEMISSION

(Abridged) The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy gamma-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. This paper describes the LAT, its pre-flight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4x4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 x,y tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an 8 layer hodoscopic configuration with a total depth of 8.6 radiation lengths. The aspect ratio of the tracker (height/width) is 0.4 allowing a large field-of-view (2.4 sr). Data obtained with the LAT are intended to (i) permit rapid notification of high-energy gamma-ray bursts (GRBs) and transients and facilitate monitoring of variable sources, (ii) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (iii) measure spectra from 20 MeV to more than 50 GeV for several hundred sources, (iv) localize point sources to 0.3 - 2 arc minutes, (v) map and obtain spectra of extended sources such as SNRs, molecular clouds, and nearby galaxies, (vi) measure the diffuse isotropic gamma-ray background up to TeV energies, and (vii) explore the discovery space for dark matter.

Application of single-sided silicon strip detector to energy and charge state measurements of medium energy ions in space

The combination of an electrostatic analyzer and a silicon strip solid detector is proposed for measuring the energy and charge state of medium energy (10–200 keV/ q) ions in space. Based on laboratory experiments, it is shown that a single-sided silicon strip detector (SSSD) has low-noise levels that provide sufficient energy resolution for charge state measurements of medium energy ions. It is also demonstrated that energy loss at a dead-layer is a critical factor for the energy resolution and measurement energy threshold; the dead-layer is measured to be ∼370 nm. A single-sided silicon strip detector with a thin dead-layer is important for the development of medium energy ion measurements into next generation satellite-borne missions.

A Performance and an Imaging Result of Silicon Strip Detector

Since capacitively coupled readout has an advantage of shielding the readout electronics from sensor leakage current, we fabricated an AC-coupled single-sided silicon strip sensor on 5-in. 380 μm-thick wafer and its active area is 3.2 × 3.2 cm2. It has 64 implanted and readout strips with a strip pitch of 500 μm. Two silicon strip sensors were mounted perpendicularly one another to get two-dimensional position information with a 5 mm space gap. Two low noise analog ASICs, VA1 chips, were used for signal readout of the strip sensor. The single-sided silicon strip detector (SSSD) consists of the two AC-coupled single-sided strip sensors and readout electronics. The SSSD was housed in an Al light-tight box. A CsI(Tl) scintillation crystal and a 2-in. photomultiplier tube were used to trigger signal events. The data acquisition systems were based on a 64 MHz FADC and control softwares for the PC-Linux platform. Experiments were performed at room temperature and silicon sensors were fully depleted. The SNRs were measured to be 29.1 ± 2.2 and 26.4 ± 0.3, respectively, for a 45 MeV proton beam and a 90Sr radioactive source. Imaging tests were performed using a Pb phantom with a 90Sr radioactive source and a 45 MeV proton beam, respectively. From the two-dimensional hit distribution, the phantom images were obtained and the position resolution was estimated to be about 240 μm.

Performance Tests of a Silicon Strip Detector with Radioactive Sources and Proton Beam

We fabricated an AC-coupled single-sided silicon strip sensor and an DC-coupled double-sided silicon strip sensor on a 5-in. 380-μm-thick wafer. The single-sided strip sensor has a size of 3.2 cm × 3.2 cm and 64 implanted and readout strips with a strip pitch of 500 μm. On the other hand, the double-sided strip sensor has an active size of 5.6 cm × 3.0 cm and 512 readout strips with a strip pitch of 50 μm. Two low-noise analog ASIC VA1 and VA1TA chips were used for signal readout of the single-sided strip and the double-sided strip sensors, respectively. The data acquisition system was based on a 12-bit 64-MHz Flash analog-to-digital converter (FADC) and control software for the PC-Linux platform. The signal-to-noise ratios of the sensor were measured with radioactive sources and a 45-MeV proton beam of the MC-50 cyclotron at Korea Institute of Radiological and Medical Sciences (KIRAMS). The performance results of the manufactured AC-coupled single-sided silicon strip detector and DC-coupled double-sided silicon strip detector are presented.

The high resolution array (HiRA) for rare isotope beam experiments

The High Resolution Array (HiRA) is a large solid-angle array of silicon strip-detectors that has been developed for use in a variety of nuclear structure, nuclear astrophysics and nuclear reaction experiments with short lived beta-unstable beams. It consists of 20 identical telescopes each composed of a thin ( 65 μ m ) single-sided silicon strip-detector, a thick (1.5 mm) double-sided silicon strip-detector, and four CsI(Tl) crystals read out by photodiodes. The array can be easily configured to meet the detection requirements of specific experiments. To process the signals from the 1920 strips in the array, an Application Specific Integrated Circuit (ASIC) was developed. The design and performance characteristics of HiRA are described.

Development and test of silicon strip detector for international linear collider

We have been designing and developing DC- and AC-coupled double-sided and single-sided silicon strip detectors for tracking device in the international linear collider (ILC). We present the electrical characteristics of the fabricated sensors such as the leakage currents and the capacitances as a function of reverse bias voltage. We also discuss results of the radiation damage test with 45 MeV proton beam of a cyclotron in Korea Institute of Radiological and Medical Science (KIRAMS) in Seoul, Korea. The leakage currents and the full depletion voltage were measured to be less than 10 nA/strip and about 60 V, respectively. We conclude that developed sensors have an excellent safety margin of radiation hardness appropriate for the ILC. The results of the signal-to-noise ratio (SNR) of the fabricated silicon strip sensors with 90Sr radioactive source and the proton beam of the KIRAMS are also presented. The SNRs of the strip sensor are measured to be 25.0 and 6.7–16.4 for the source test and for the proton beam test, respectively.

Signal-to-Noise Ratio Measurement for Silicon Strip Sensors with a Proton Beam

The signal-to-noise performance of DC-coupled single-sided silicon strip detectors (SSSD) of our own design and front-end readout electronics is presented. Good separation of the signal from the noise is essential for the successful accomplishment of their intended functions. For the tracking of charged particles, a good signal-to-noise ratio (>10) is required. For X-ray applications, much better signal-to-noise performance is desirable because of less energy being deposited by an incident photon. We report a signal-to-noise ratio of the fabricated DC-coupled SSSD with electronics for the 45-MeV proton beam from the MC-50 cyclotron at the Korea Institute of Radiological and Medical Science (KIRAMS) in Seoul, Korea.

Alignment of the ZEUS micro-vertex detector using cosmic tracks

ZEUS Micro-Vertex Detector (MVD) was installed in ZEUS after the HERA upgrade in 2000. MVD is a precise position detector consisting of 712 single-sided silicon strip detectors. The alignment of the barrel MVD has been performed in units of ladders using cosmic tracks. The procedure used is an iterative χ 2 minimization, where χ 2 is defined locally for each ladder. The procedure is numerically stable since it only requires an inversion of 30 6 × 6 matrices and reasonably fast in spite of the iterative approach.

Development of a novel silicon stripixel detector for RHIC-PHENIX detector upgrade

A new single-sided silicon strip detector has been developed for the silicon vertex tracker of the PHENIX detector at the Relativistic Heavy Ion Collider in Brookhaven National Laboratory (BNL). The novel "stripixel" detector concept developed by the BNL Instrumentation Division was applied to the first prototype silicon sensor. The novel feature of the stripixel concept is two-dimensional (2-D) position sensitivity with single-sided processing achieved by charge sharing between two interleaved electrodes in one pixel. Signals are read out projectively by double layers of aluminum strips. The first prototype stripixel sensors with the size of 34.3 /spl times/ 64.6 mm and thickness of 250 and 400 /spl mu/m were fabricated. The detector with readout electronics was constructed to evaluate the prototype sensor performance by using an analog multiplexer chip with charge sensitive preamplifier-shaper circuits (VA2 chip of IDEAS). The sensor performance on charge sharing, detection efficiency, signal-to-noise ratio, and position resolution has been tested with a radioactive source and a GeV particle beam at KEK-PS. The stripixel detector concept, the specification of the first prototype stripixel sensor, and the test results are presented.

The ZEUS micro-vertex detector

During the HERA luminosity shutdown period 2000/01 the tracking system of the ZEUS experiment has been upgraded with a silicon Micro Vertex Detector (MVD). The barrel part of the detector consists of three layers of single sided silicon strip detectors, while the forward section is composed of four wheels. In this report we shortly present the assembly procedure and in more details the test beam results on the spatial resolution of half modules. The first results of a cosmic ray test are presented and the radiation monitor system is described.

Silicon strip detector as a real-time, fast, medium-segmented hodoscope

We have developed a single-sided silicon strip detector with a sensitive area of 64×64 mm 2 as a real-time, fast and medium-segmented hodoscope for particle physics experiments in high beam background environment. The signal of each 2 mm wide readout strip was integrated in a hybrid preamplifier with a decay constant of 10 μs. The output was then amplified 20 times and shaped to a peaking time of ∼50 ns in a shaping amplifier. The performance was first examined on a test bench, and then with an intense π −/μ −/e − beam. The Equivalent Noise Charge (ENC, 1 σ) at the preamplifier input was ∼2000 e (9% of the signal for single minimum ionizing particle ∼22 000 e) at low beam rate, and increased by 10% (or 20%) at a high rate of 150 kHz (300 kHz) per readout-strip. As the cable length ( L) from silicon board to preamplifier increased, the ENC increased from 2000 e for L=0.2 m to 2600 e for 0.5 m, 3500 e for 1 m, 3800 e for 1.5 m, and 4200 e for 2 m.

The ZEUS microvertex detector

A new vertex detector for the ZEUS experiment at HERA will be installed during the 1999–2000 shutdown, for the high-luminosity runs of HERA. It will allow to reconstruct secondary vertex tracks, coming from the decay of long-lived particles with a lifetime of about 10 −12 s, and improve the global momentum resolution of the tracking system. The interaction region will be surrounded with single-sided silicon strip detectors, with capacitive charge division: three double layers in the central region (600 detectors), and 4 “wheels” in the forward region (112 silicon planes). Due to the high number of readout channels, 512 readout strips per silicon plane in the barrel region and 480 in the forward part, and the large coverage of the vertex detector (almost 1 m long), the front-end electronics has to be placed on top of the detectors and has to be radiation tolerant since doses up to 2 kGy are expected near the interaction region. The HELIX chip has been chosen as analog chip with a low-noise, charge-sensitive amplifier/shaper. The chip integrates 128 read out channels which are sampled in an analog pipeline with the HERA bunch crossing frequency of 10.4 MHz. A review of the status of the project is presented. A test program is underway in order to gain experience in the understanding of the detectors and their performance characteristics (i.e. detection efficiency, noise, large angle track position resolution, irradiation studies).

Load capacitance of single-sided silicon strip detectors with double-metal layers

The load capacitance of the single-sided silicon microstrip detector with double-metal layers was studied. In order to understand the capacitance due to the double-metal structure, we have fabricated single-sided microstrip detectors with different double-metal structure on the junction (p) side or the ohmic (n) side. The measured capacitance was compared with the prediction of LEPSI-CRN model.