Double-sided Silicon Strip Detectors Research Articles

β-particle energy-summing correction for β-delayed proton emission measurements

A common approach to studying β-delayed proton emission is to measure the energy of the emitted proton and corresponding nuclear recoil in a double-sided silicon-strip detector (DSSD) after implanting the β-delayed proton-emitting (βp) nucleus. However, in order to extract the proton-decay energy, the measured energy must be corrected for the additional energy implanted in the DSSD by the β-particle emitted from the βp nucleus, an effect referred to here as β-summing. We present an approach to determine an accurate correction for β-summing. Our method relies on the determination of the mean implantation depth of the βp nucleus within the DSSD by analyzing the shape of the total (proton + recoil + β) decay energy distribution shape. We validate this approach with other mean implantation depth measurement techniques that take advantage of energy deposition within DSSDs upstream and downstream of the implantation DSSD.

A nuclear geochemical analysis system for boron quantification using a focused ion beam

Ion beam analysis has for decades been used as a tool for geochemical analysis of trace elements using both X-rays (particle induced X-ray emission) and nuclear reaction analysis. With the geoanalytical setup at the Lund Ion Beam Analysis Facility, the boron content in geological samples with a spatial resolution of 1 µm is determined through nuclear reaction analysis. In the newly upgraded setup, a single detector has been replaced by a double sided silicon strip detector with 2048 segments. After optimization, boron content in geological samples as low as 1 µg g−1 can be measured.

New analog electronics for the new challenges in the synthesis of superheavy elements

A new series of experiments aimed at the synthesis and study of decay properties of the most neutron-deficient isotopes of element Fl (Z = 114) and of the heaviest isotopes of 118 element is planned at the DGFRS (FLNR JINR). An appropriate registering system is to be implemented to transfer spectrometric data from double-sided silicon strip detector (DSSD). New analog modules were designed that allow to simplify existing multi-channel measurement system and to improve the real-time method of “active correlations” in search for the rare events of SHE formation and decay. The main features of the new modules the 16-channel charge-sensitive preamplifier, the 16-channel analog multiplexer and the 1.25 MSPS 12-bit Parallel ADC are presented.

O17+Ni58scattering and reaction dynamics around the Coulomb barrier

This work aims at investigating the projectile binding energy influence on the reaction dynamics, introducing new results and new data analysis methods in order to overcome some typically encountered problems, such as the identification of reaction products differing by few mass units and the discrimination of direct reaction processes. The O17+Ni58 collision was studied at five near-barrier energies employing a compact experimental setup consisting of four double-sided silicon strip detectors (DSSSDs). Different reaction processes, namely the elastic and inelastic scattering and the 1n stripping, were discriminated by means of a detailed analysis of the experimental energy spectra based on Monte Carlo simulations. The elastic scattering angular distributions were investigated within the framework of the optical model using Woods-Saxon and double-folding potentials. The total reaction cross sections were extracted and the reduced cross sections compared with those obtained for F17 (Sp=0.600 MeV), the mirror nucleus of O17 (Sn=4.143 MeV), and for the tightly bound O16 projectile. The O17+Ni58 total reaction cross sections were larger than those for O16 on the same target at the lowest energies studied, becoming identical, within errors, as the incident energy increased above the Coulomb barrier. This behavior was related to a strong contribution from the 1n-stripping channel at the lowest energies.5 MoreReceived 20 June 2016DOI:https://doi.org/10.1103/PhysRevC.94.024622©2016 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBinding energy & massesBreakup reactionsLow & intermediate energy heavy-ion reactionsOptical, coupled-channel & distorted wave modelsTransfer reactionsNuclear Physics

CsI–Silicon Particle detector for Heavy ions Orbiting in Storage rings (CsISiPHOS)

A heavy-ion detector was developed for decay studies in the Experimental Storage Ring (ESR) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. This detector serves as a prototype for the in-pocket particle detectors for future experiments with the Collector Ring (CR) at FAIR (Facility for Antiproton and Ion Research). The detector includes a stack of six silicon pad sensors, a double-sided silicon strip detector (DSSD), and a CsI(Tl) scintillation detector. It was used successfully in a recent experiment for the detection of the β+-decay of highly charged 142Pm60+ ions. Based on the ΔE/E technique for particle identification and an energy resolution of 0.9% for ΔE and 0.5% for E (Full Width at Half Maximum (FWHM)), the detector is well-suited to distinguish neighbouring isobars in the region of interest.

Thick silicon microstrip detectors simulation for PACT: Pair and Compton Telescope

PACT is a space borne Pair and Compton Telescope that aims to make a sensitive survey of the gamma-ray sky between 100keV and 100MeV. It is based upon two main components: a silicon-based gamma-ray tracker and a crystal-based calorimeter. In this paper we will explain the imaging technique of PACT as a Multi-layered Compton telescope (0.1–10MeV) and its major improvements over its predecessor COMPTEL. Then we will present a simulation study to optimize the silicon tracker of PACT. This tracker is formed of thousands of identical silicon double sided strip detectors (DSSDs). We have developed a simulation model (using SILVACO) to simulate the DSSD performance while varying its thickness, impurity concentration of the bulk material, electrode pitch, and electrode width. We will present a comprehensive overview of the impact of each varied parameter on the DSSD performance, in view of the application to PACT. The considered DSSD parameters are its depletion voltage, capacitance, and leakage current. After the selection of the PACT DSSD, we will present a simulation of the performance of the PACT telescope in the 0.1–10MeV range.

Development, prototyping and characterization of double sided silicon strip detectors

Double sided DC-coupled silicon strip detectors with geometry of 65mm×65mm have been developed in India for nuclear physics experiments. The detectors have 64 P+ strips on the front side and 64 N+ strips on the backside with a pitch of 0.9mm. These detectors were fabricated using a twelve mask layer process involving double sided wafer processing technology. Semiconductor process and device simulations were carried out in order to theoretically estimate the impact of important design and process parameters on the breakdown voltage of detectors. The performance of the first lot of prototype detectors has been studied using static characterization tests and using an alpha source. The characterization results demonstrate that the detectors have low leakage currents and good uniformity over the detector area of about 40cm2. Overview of the detector design, fabrication process, simulation results and initial characterization results of the detectors are presented in this paper.

Direct observation of theBa114→Xe110→Te106→Sn102tripleα-decay chain using position and time correlations

The triple $\ensuremath{\alpha}$-decay chain $^{114}\mathrm{Ba}\ensuremath{\rightarrow}^{110}\mathrm{Xe}\ensuremath{\rightarrow}^{106}\mathrm{Te}\ensuremath{\rightarrow}^{102}\mathrm{Sn}$ has been directly observed for the first time, following the $^{58}\mathrm{Ni}(^{58}\mathrm{Ni},2n)$ reaction. Implantation of $^{114}\mathrm{Ba}$ nuclei into a double-sided silicon-strip detector has allowed their $\ensuremath{\alpha}$ decays to be correlated in position and time with the $\ensuremath{\alpha}$ decays of the daughter $(^{110}\mathrm{Xe})$ and granddaughter $(^{106}\mathrm{Te})$ nuclei. In total, 17 events have been assigned to the $^{114}\mathrm{Ba}\ensuremath{\rightarrow}^{110}\mathrm{Xe}\ensuremath{\rightarrow}^{106}\mathrm{Te}\ensuremath{\rightarrow}^{102}\mathrm{Sn}$ triple $\ensuremath{\alpha}$-decay chain. The energy of the $^{114}\mathrm{Ba} \ensuremath{\alpha}$ decay has been measured to be ${E}_{\ensuremath{\alpha}}=3480$(20) keV, which is 70 keV higher than the previously measured value, and the half-life of $^{114}\mathrm{Ba}$ has been measured with improved accuracy, to be ${380}_{\ensuremath{-}110}^{+190}$ ms. A revised ${Q}_{^{12}\mathrm{C}}$ value of 19 035(45) keV for $^{114}\mathrm{Ba}$ is presented.

Evidence for a 3.8 MeV state inBe9

The breakup reaction $^{9}\mathrm{Be}(^{4}\mathrm{He},3\ensuremath{\alpha})\mathit{n}$ was measured using an array of four double-sided silicon strip detectors at beam energies of 22 and 26 MeV. Excited states in $^{9}\mathrm{Be}$ up to 8 MeV were populated and reconstructed through measurements of the charged reaction products. Evidence is given for a state in $^{9}\mathrm{Be}$ at $3.{82}_{\text{-0.09}}^{\text{+0.08}}$ MeV with $\mathrm{\ensuremath{\Gamma}}={1240}_{\text{-90}}^{\text{+270}}$ keV. This is consistent with two recent measurements of a state with similar properties in the mirror nucleus $^{9}\mathrm{B}$. An analysis of the reduced widths ($^{8}\mathrm{Be}_{\mathrm{g}.\mathrm{s}.}$ channel) of this state along with the proposed mirror state has led to a firm limit of $J\ensuremath{\le}7/2$ and a tentative assignment of ${J}^{\ensuremath{\pi}}=1/{2}^{\ensuremath{-}}$ or $3/{2}^{\ensuremath{-}}$.

The experimental set-up of the RIB in-flight facility EXOTIC

We describe the experimental set-up of the Radioactive Ion Beam (RIB) in-flight facility EXOTIC consisting of: (a) two position-sensitive Parallel Plate Avalanche Counters (PPACs), dedicated to the event-by-event tracking of the produced RIBs and to time of flight measurements and (b) the new high-granularity compact telescope array EXPADES (EXotic PArticle DEtection System), designed for nuclear physics and nuclear astrophysics experiments employing low-energy light RIBs. EXPADES consists of eight ΔE–Eres telescopes arranged in a cylindrical configuration around the target. Each telescope is made up of two Double Sided Silicon Strip Detectors (DSSSDs) with a thickness of 40/60μm and 300μm for the ΔE and Eres layer, respectively. Additionally, eight ionization chambers were constructed to be used as an alternative ΔE stage or, in conjunction with the entire DSSSD array, to build up more complex triple telescopes. New low-noise multi-channel charge-sensitive preamplifiers and spectroscopy amplifiers, associated with constant fraction discriminators, peak-and-hold and Time to Amplitude Converter circuits were developed for the electronic readout of the ΔE stage. Application Specific Integrated Circuit-based electronics was employed for the treatment of the Eres signals. An 8-channel, 12-bit multi-sampling 50MHz Analog to Digital Converter, a Trigger Supervisor Board for handling the trigger signals of the whole experimental set-up and an ad hoc data acquisition system were also developed. The performance of the PPACs, EXPADES and of the associated electronics was obtained offline with standard α calibration sources and in-beam by measuring the scattering process for the systems 17O+58Ni and 17O+208Pb at incident energies around their respective Coulomb barriers and, successively, during the first experimental runs with the RIBs of the EXOTIC facility.

The Belle II SVD data readout system

The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the standard model.172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC).Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network.We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing.

A bonding study toward the quality assurance of Belle-II silicon vertex detector modules

A silicon vertex detector (SVD) for the Belle-II experiment comprises four layers of double-sided silicon strip detectors (DSSDs), assembled in a ladder-like structure. Each ladder module of the outermost SVD layer has four rectangular and one trapezoidal DSSDs supported by two carbon-fiber ribs. In order to achieve a good signal-to-noise ratio and minimize material budget, a novel chip-on-sensor “Origami” method has been employed for the three rectangular sensors that are sandwiched between the backward rectangular and forward (slanted) trapezoidal sensors. This paper describes the bonding procedures developed for making electrical connections between sensors and signal fan-out flex circuits (i.e., pitch adapters), and between pitch adapters and readout chips as well as the results in terms of the achieved bonding quality and pull force.

The Si/CdTe semiconductor camera of the ASTRO-H Hard X-ray Imager (HXI)

The Hard X-ray Imager (HXI) is one of the instruments onboard the ASTRO-H mission [1–4] to be launched in early 2016. The HXI is the focal plane detector of the hard X-ray reflecting telescope that covers an energy range from 5 to 80keV. It will execute observations of astronomical objects with a sensitivity for point sources as faint as 1/100,000 of the Crab nebula at >10keV. The HXI camera – the imaging part of the HXI – is realized by a hybrid semiconductor detector system that consists of silicon (Si) and cadmium telluride (CdTe) semiconductor detectors. Here, we present the final design of the HXI camera and report on the development of the flight model. The camera is composed of four layers of Double-sided Silicon Strip Detectors (DSSDs) and one layer of CdTe Double-sided Strip Detector (CdTe-DSD), each with an imaging area of 32mm×32mm. The strip pitch of the Si and CdTe sensors is 250μm, and the signals from all 1280 strips are processed by 40 Application Specified Integrated Circuits (ASICs) developed for the HXI. The five layers of sensors are vertically stacked with a 4mm spacing to increase the detection efficiency. The thickness of the sensors is 0.5mm for the Si, and 0.75mm for the CdTe. In this configuration, soft X-ray photons will be absorbed in the Si part, while hard X-ray photons will go through the Si part and will be detected in the CdTe part. The design of the sensor trays, peripheral circuits, power connections, and readout schemes are also described. The flight models of the HXI camera have been manufactured, tested and installed in the HXI instrument and then on the satellite.

Front-end readout electronics considerations for Silicon Tracking System and Muon Chamber

Silicon Tracking System (STS) and Muon Chamber (MUCH) are components of the Compressed Baryonic Matter (CBM) experiment at FAIR, Germany. STS will be built from 8 detector stations located in the aperture of the magnet. Each station will be built from double-sided silicon strip detectors and connected via kapton microcables to the readout electronics at the perimeter of each station. The challenging physics program of the CBM experiment requires from the detector systems very high performance. Design of the readout ASIC requires finding an optimal solution for interaction time and input charge measurements in the presence of: tight area (channel pitch: 58 μ m), noise (< 1000 e- rms), power (< 10 mW/channel), radiation hardness and speed requirements (average hit rate: 250 khit/s/channel). This paper presents the front-end electronics' analysis towards prototype STS and MUCH readout ASIC implementation in the UMC 180 nm CMOS process and in-system performance with the emphasis on preferable detector and kapton microcable parameters and input amplifiers' architecture and design.

Effects of the interstrip gap on the efficiency and response of Double Sided Silicon Strip Detectors

In this work the effects of the segmentation of the electrodes of Double Sided Silicon Strip Detectors (DSSSDs) are investigated. In order to characterize the response of the DSSSDs we perform a first experiment by using tandem beams of different energies directly sent on the detector and a second experiment by mean of a proton microbeam. Results show that the effective width of the inter-strip region and the efficiency for full energy detection, varies with both detected energy and bias voltage. The experimental results are qualitatively reproduced by a simplified model based on the Shockley-Ramo-Gunn framework.

Clusters in neutron-rich light nuclei

Due to their high selectivity, transfer and sequential decay reactions are powerful tools for studies of both single particle (nucleon) and cluster states in light nuclei. Their use is particularly simple for investigations of α -particle clustering (because α -particle has J π =0 + , which simplifies spin and parity assignments to observed cluster states), but they are also easily applicable to other types of clustering. Recent results on clustering in neutron-rich isotopes of beryllium, boron and carbon obtained measuring the 10 B+ 10 B reactions (at 50 and 72 MeV) are presented. The highly efficient and segmented detector systems used, built from 4 Double Sided Silicon Strip Detectors (DSSSD) allowed detection of double and multiple coincidences and, in that way, studies of states populated in transfer reactions, as well as their sequential decay.

Construction and test of the first Belle II SVD ladder implementing the origami chip-on-sensor design

The Belle II Silicon Vertex Detector comprises four layers of double-sided silicon strip detectors (DSSDs), consisting of ladders with two to five sensors each. All sensors are individually read out by APV25 chips with the Origami chip-on-sensor concept for the central DSSDs of the ladders. The chips sit on flexible circuits that are glued on the top of the sensors. This concept allows a low material budget and an efficient cooling of the chips by a single pipe per ladder. We present the construction of the first SVD ladders and results from precision measurements and electrical tests.

A Compton camera prototype for prompt gamma medical imaging

A Compton camera prototype for a position-sensitive detection of prompt gamma rays from proton-induced nuclear reactions is being developed in Garching. The detector system allows to track the Compton-scattered electrons. The camera consists of a monolithic LaBr3:Ce scintillation absorber crystal, read out by a multi-anode PMT, preceded by a stacked array of 6 double-sided silicon strip detectors acting as scatterers. The LaBr3:Ce crystal has been characterized with radioactive sources. Online commissioning measurements were performed with a pulsed deuteron beam at the Garching Tandem accelerator and with a clinical proton beam at the OncoRay facility in Dresden. The determination of the interaction point of the photons in the monolithic crystal was investigated.

Isoscalar giant resonance studies in a stored-beam experiment within EXL

In the first campaign of the exotic nuclei studied with light-ion induced reaction in storage rings (EXL) collaboration at the existing storage ring experimental heavy-ion storage ring (ESR) at Helmholtz Center for Heavy Ion Research (GSI), we performed the first experiments using a stored beam of 58Ni and an internal helium gas-jet target aiming for the investigation of isoscalar giant resonances in inverse kinematics. In this experiment, inelastically scattered recoil particles (at very forward angles, °) were detected with a dedicated setup, including ultra-high vacuum (UHV)-compatible double-sided silicon strip detector (DSSDs). Preliminary results show evidence for the excitation of the isoscalar giant monopole resonance (ISGMR) in the 58Ni nucleus. This opens the opportunity to study in the near future giant resonances also with stored radioactive beams, like 56Ni, and extract important information about the nuclear matter incompressibility. In the present work the current status of the data analysis and results are shown and discussed.

Deuterium microscopy using 17 MeV deuteron–deuteron scattering

Using 17MeV deuterons as a micrometer focused primary beam, we performed deuterium microscopy by using the deuteron–deuteron (dd) scattering reaction. We describe our new box like detector setup consisting of four double sided silicon strip detectors (DSSSD) with 16 strips on each side, each covering up to 0.5sr solid angle for coincidence detection. This method becomes a valuable tool for studies of hydrogen incorporation or dynamic processes using deuterium tagging. The background from natural hydrocarbon or water contamination is reduced by the factor 150ppm of natural abundance of deuterium in hydrogen. Deuterium energies of up to 25MeV, available at the microprobe SNAKE, are ideal for the analysis of thin freestanding samples so that the scattered particles are transmitted to the detector. The differential cross section for the elastic scattering reaction is about the same as for pp-scattering (~100mb/sr). The main background due to nuclear reactions is outside the energy window of interest. Deuteron–proton (dp) scattering events give an additional signal for hydrogen atoms, so the H/D-ratio can be monitored in parallel.A deuterium detection limit due to accidental coincidences of 3at-ppm down to less than 1at-ppm is demonstrated on deuterated polypropylen sheets as well as thick polycarbonate sheets after various stages of coincidence filtering that is possible with our granular detector.