Conformal tracking is an innovative and comprehensive pattern recognition technique using a cellular automaton-based track finding performed in a conformally-mapped space. It is particularly well-suited for light-weight silicon systems with high position resolution, such as the next generation of tracking detectors designed for future electron-positron colliders. The algorithm has been developed and validated with simulated data of the CLICdet tracker. It has demonstrated not only excellent performance in terms of tracking efficiency, fake rate and track parameters resolution but also robustness against the high beam-induced background levels. Thanks to its geometry-agnostic nature and its modularity, the algorithm is very flexible and can easily be adapted to other detector designs and experimental environments at future $e^+e^-$ colliders.
The readout systems for the ATLAS silicon trackers and liquid argon calorimeters utilize vertical-cavity surface-emitting laser diodes to communicate between on and off detector readout components. A number of these VCSEL devices have failed well before their expected lifetime. We summarize the failure history and present what has been learned thus far about failure mechanisms and the dependence of the lifetime on environmental conditions.
A silicon photomultiplier (SiPM) array has been developed at FBK-irst having 32 channels and a dimension of 8.0 x 1.1 mm^2. Each 250 um wide channel is subdivided into 5 x 22 rectangularly arranged pixels. These sensors are developed to read out a modular high resolution scintillating fiber tracker. Key properties like breakdown voltage, gain and photon detection efficiency (PDE) are found to be homogeneous over all 32 channels of an SiPM array. This could make scintillating fiber trackers with SiPM array readout a promising alternative to available tracker technologies, if noise properties an…
A Kalman Filter alignment algorithm has been applied to cosmic-ray data. We discuss the alignment algorithm and an experiment-independent implementation including outlier rejection and treatment of weakly determined parameters. Using this implementation, the algorithm has been applied to data recorded with one CMS silicon tracker endcap. Results are compared to both photogrammetry measurements and data obtained from a dedicated hardware alignment system, and good agreement is observed.
In next ten years, the Large Hadron Collider will be upgraded to the High Luminosity LHC (HL-LHC), resulting in ten time more integrated luminosity. To withstand the much harsher radiation and occupancy conditions of the HL-LHC, the inner tracker of the ATLAS detector must be redesigned and rebuilt completely. The design of the ATLAS Upgrade inner tracker (ITk) has already been defined. It consists of several layers of silicon particle detectors. The innermost layers will be composed of silicon pixel sensors, and the outer layers will consist of silicon microstrip sensors. This paper will focu…
This paper describes the integration structures for the silicon strips tracker of the ATLAS detector proposed for the Phase-II upgrade of the Large Hadron Collider (LHC), also referred to as High Luminosity LHC (HL-LHC). In this proposed detector Silicon strip sensors are arranged in highly modular structures, called `staves' and `petals'. This paper presents performance results from the latest prototype stave built at Berkeley. This new, double-sided prototype is composed of a specialized core structure, in which a shield-less bus tape is embedded in between carbon fiber lay-ups. A detailed d…
During the high-luminosity phase of the LHC (HL-LHC), planned to start around 2027, the accelerator is expected to deliver an instantaneous peak luminosity of up to $7.5\times10^{34}$ cm$^{-2}$s$^{-1}$. A total integrated luminosity of $3000$ or even $4000$~fb$^{-1}$ is foreseen to be delivered to the general purpose detectors ATLAS and CMS over a decade, thereby increasing the discovery potential of the LHC experiments significantly. The CMS detector will undergo a major upgrade for the HL-LHC, with entirely new tracking detectors consisting of an Outer Tracker and Inner Tracker. However, the…
The inner drift chamber of the BESIII is encountering serious aging problem after five year's running. For the first layer, the decrease in gas gain is about 26% from 2009 to 2013. The upgrade of the inner tracking detector has become an urgent problem for the BESIII experiment. An inner tracker using CMOS pixel sensors is an important candidate because of its great advantages on spatial resolution and radiation hardness. In order to carry out a Monte Carlo study on the expected performance, a Geant4-based full simulation for the silicon pixel detector has been implemented. The tracking method…
The Physics and Data Quality Monitoring (DQM) framework aims at providing a homogeneous monitoring environment across various applications related to data taking at the CMS experiment. In this contribution, the DQM system for the Silicon Strip Tracker will be introduced. The set of elements to assess the status of detector will be mentioned, along with the way to identify problems and trace them to specific tracker elements. Monitoring tools, user interfaces and automated software will be briefly described. The system was used during extensive cosmic data taking of CMS in Autumn 2008, where it…
With over 200 square meters of sensitive Silicon and almost 10 million readout channels, the Silicon Strip Tracker of the CMS experiment at the LHC will be the largest Silicon strip detector ever built. The design, construction and expected performance of the CMS Tracker is reviewed in the following.
The CMS experiment at the LHC features the largest Silicon Strip Detector ever built. The impact of the operating conditions and physics requirements on the design choices of the CMS Silicon Tracker is reviewed. The readiness of the Silicon Strip Tracker for the tentatively scheduled CMS commissioning in Summer 2008 is briefly described.
With an expected ten-fold increase in luminosity in S-LHC, the radiation environment in the tracker volumes will be considerably harsher for silicon-based detectors than the already harsh LHC environment. Since 2006, a group of CMS institutes, using a modified CMS DAQ system, has been exploring the use of Magnetic Czochralski silicon as a detector element for the strip tracker layers in S-LHC experiments. Both p+/n-/n+ and n+/p-/p+ sensors have been characterized, irradiated with proton and neutron sources, assembled into modules, and tested in a CERN beamline. There have been three beam studi…
Several future high-energy physics facilities are currently being planned. The proposed projects include high energy $e^+ e^-$ circular and linear colliders, hadron colliders and muon colliders, while the Electron-Ion Collider (EIC) has already been approved for construction at the Brookhaven National Laboratory. Each proposal has its own advantages and disadvantages in term of readiness, cost, schedule and physics reach, and each proposal requires the design and production of specific new detectors. This paper first presents the performances required to the future silicon tracking systems at …
The SiliconMicro-strip Tracker (SMT) at the DØ experiment in the Fermilab Tevatron collider has been operating since 2001. In 2006, an additional layer, referred to as 'Layer 0', was installed to improve impact parameter resolution and compensate for detector degradation due to radiation damage to the original innermost SMT layer. The SMT detector provides valuable tracking and vertexing information for the experiment. This contribution will highlight aspects of the long term operation of the SMT, including the impact of the silicon readout test-stand. Due to the full integration of the test-s…
The strategies for and the performance of the CMS silicon tracking system alignment during the 2015-2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios.
The alignment of tracking detectors is crucial for the physics programme at the LHC, especially for precision measurements like the W mass. The alignment of the ATLAS silicon tracking detectors with a total of 5832 modules poses an unprecedented challenge. In this poster, two track-based alignment algorithms at ATLAS will be covered: the Global chi^2 Algorithm based on chi^2 minimisation, and the Robust Alignment Algorithm based on centering residual distributions. On a time scale of minutes and hours, the geometry of the silicon tracking detectors can be monitored with the Frequency Scanning …
Using the simulation framework of the SiD detector to study the Higgs -> mumu decay channel showed a considerable gain in signal significance could be achieved through an increase in charged particle momentum resolution. However more detailed simulations of theZ -> mumu decay channel demonstrated that significant improvement in the resolution could not be achieved through an increase in tracker granularity. Conversely detector stability studies into missing/dead vertex layers using longer lived particles displayed an increase in track resolution. The existing 9.15 cm x 25 μm silicon strip geom…
The CMS Silicon Strip tracker is a very large scale tracker entirely based on silicon strip detectors technology. The integration of modules, electronics, mechanics and services has been completed within the last eighteen months; first large standalone sub-structures (shells, disks, rods, petals depending on the tracker subdetector) have been integrated and verified; then they have been brought together into the final configuration. The CMS silicon tracker design and its construction is reviewed with particular emphasis on the procedures and quality checks deployed to successfully assembly sev…
We report on the R\&D for a first prototype of a silicon tracker based on an alternative approach for fast track finding. The working principle is inspired from neurobiology, in particular by the processing of visual images by the brain as it happens in nature. It is based on extensive parallelisation of data distribution and pattern recognition. In this work we present the design of a practical device that consists of a telescope based on single-sided silicon detectors; we describe the data acquisition system and the implementation of the track finding algorithms using available digital logic…
The CMS collaboration is constructing the largest silicon tracker ever built with an active silicon area of 200 m^2 to provide robust charged particle tracking and vertex reconstruction within the 4T magnetic field of the CMS Solenoid. The design of the detector, the status of the construction and the performance of the substructures are reviewed.
During autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip…
The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than the one of LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 collaboration "…
With an active silicon area of more than 200 squaremetres, the silicon strip tracker of the CMS experiment, one of the experiments currently under construction for the future Large Hadron Collider at CERN, will be by far the largest silicon tracker in the world. Efficient mass production and rigid quality control are crucial to finish the detector, comprising of more than 15000 silicon strip modules, in time with optimal quality. After excellent performance of substructures has been proven in various test beam experiments, integration of the active detector elements into the mechanical support…
The CLIC Tracker Detector (CLICTD) is a monolithic pixelated sensor chip produced in a $180$ nm imaging CMOS process built on a high-resistivity epitaxial layer. The chip, designed in the context of the CLIC tracking detector study, comprises a matrix of ${16\times128}$ elongated pixels, each measuring ${300\times30}$ $μ$m$^2$. To ensure prompt charge collection, every elongated pixel is segmented in eight sub-pixels, each containing a collection diode and a separate analog front-end. A simultaneous $8$-bit time measurement with $10$ ns time bins and $5$-bit energy measurement with programmabl…
We present prototype modules for a tracking detector consisting of multiple layers of 0.25 mm diameter scintillating fibers that are read out by linear arrays of silicon photomultipliers. The module production process is described and measurements of the key properties for both the fibers and the readout devices are shown. Five modules have been subjected to a 12 GeV/c proton/pion testbeam at CERN. A spatial resolution of 0.05 mm and light yields exceeding 20 detected photons per minimum ionizing particle have been achieved, at a tracking efficiency of more than 98.5%. Possible techniques for …
The D0 Run II silicon microstrip tracker (SMT) has 3 square meters of Si area. There are 792,576 channels read out by 6192 SVXIIe chips on 912 read out modules. The SMT provides track and vertex reconstruction capabilities over the full pseudorapidity coverage of the D0 detector. The full detector has been running successfully since April 2002. This presentation covers the experience in commissioning and operating, the recent electronics upgrade which improved stability of the SMT and estimates of the radiation damage.
The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15% of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hi…
We present recent improvements in the performance of the reconstruction of non-prompt track in the SiD Detector Concept Design, including initial results on the effect of longitudinal segmentation in the SiD tracker. We also describe a generic tracking validation package developed at SCIPP.
The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker s…
With a total area of 210 squaremeters and about 15000 single silicon modules the silicon strip tracker of the CMS experiment at the LHC will be the largest silicon strip detector ever built. While the performance of the individual mechanical and electronic components has already been tested extensively, their interplay in larger integrated substructures also has to be studied before mass production can be launched, in order to ensure the envisaged performance of the overall system. This is the main purpose of the system tests, during which hardware components as final as possible are being int…
This report presents recent results on track reconstruction and alignment with the silicon tracker of the CMS experiment at the LHC, obtained with a full detector simulation. After an overview of the layout of the tracker and its material budget, the baseline algorithm for track reconstruction is discussed. The performance of the track reconstruction and its dependence on misalignment is shown. The concept for alignment of the CMS tracker, using a laser alignment system as well as three different track-based alignment algorithms, is presented.
This conference proceeding presents the first results of the full CMS Tracker alignment based on several million reconstructed tracks from the cosmic data taken during the commissioning runs with the detector in its final position and magnetic field present. The all-silicon design of the CMS Tracker poses new challenges in aligning a complex system with 15\,148 silicon strip and 1440 silicon pixel modules. For optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of about one micrometer. The modules, well illuminated by cosmic ra…
For the Phase-II Upgrade of the ATLAS detector at CERN, the current ATLAS Inner Detector will be replaced with the ATLAS Inner Tracker. The ATLAS Inner Tracker will be an all-silicon detector, consisting of a pixel tracker and a strip tracker. Sensors for the ITk strip tracker are required to have a low leakage current up to bias voltages of -700 V to maintain a low noise and power dissipation. In order to minimise sensor leakage currents, particularly in the high-radiation environment inside the ATLAS detector, sensors are foreseen to be operated at low temperatures and to be manufactured fro…
The CMS silicon tracker, consisting of 1440 silicon pixel and 15148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to a precision of 3-4 microns RMS in the barrel and 3-14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several methods, including the laser alignment system, and compared with predictions obtained from simulation. Correlated systematic eff…
The hit response of silicon vertex and tracking detectors to muon collider beam background and results of a study of hit reducing techniques are presented. The background caused by decays of the 750 GeV/c m+ and m- beams was simulated using the MARS15 program, which included the infrastructure of the beam line elements near the detector and the 10 degree nozzles that shield the detector from this background. The ILCRoot framework, along with the Geant4 program, was used to simulate the hit response of the silicon vertex and tracker detectors to the muon decay background remaining after the shi…
When testing and calibrating particle detectors in a test beam, accurate tracking information independent of the detector being tested is extremely useful during the offline analysis of the data. A general-purpose Silicon Beam Tracker (SBT) was constructed with an active area of 32.0 x 32.0 mm2 to provide this capability for the beam calibration of the Cosmic Ray Energetics And Mass (CREAM) calorimeter. The tracker consists of two modules, each comprised of two orthogonal layers of 380 μm thick silicon strip sensors. In one module each layer is a 64-channel AC-coupled single-sided silicon stri…
The Silicon Tracker (STK) is a detector of the DAMPE satellite to measure the incidence direction of high energy cosmic ray. It consists of 6 X-Y double layers of silicon micro-strip detectors with 73,728 readout channels. It's a great challenge to readout the channels and process the huge volume of data in the critical space environment. 1152 Application Specific Integrated Circuits (ASIC) and 384 ADCs are adopted to readout the detector channels. The 192 Tracker Front-end Hybrid (TFH) modules and 8 identical Tracker Readout Board (TRB) modules are designed to control and digitalize the front…
The Dark Matter Particle Explorer (DAMPE) is an upcoming scientific satellite mission for high energy gamma-ray, electron and cosmic rays detection. The silicon tracker (STK) is a sub detector of the DAMPE payload with an excellent position resolution (readout pitch of 242um), which measures the incident direction of particles, as well as charge. The STK consists 12 layers of Silicon Micro-strip Detector (SMD), equivalent to a total silicon area of 6.5m$^2$. The total readout channels of the STK are 73728, which leads to a huge amount of raw data to be dealt. In this paper, we focus on the on-…
This thesis presents the work carried out in the testing of the ATLAS Phase-II Upgrade electronic systems in the future strips tracker after 2023, to be installed for operations in the HL-LHC period. The high luminosity and number of interactions per crossing that will happen after the HL-LHC starts require a complete replacement of the ATLAS tracker. The systems that have been defined for the Phase-II Upgrade will be designed to cope with that increased radiation and have the right granularity to maintain the performance with higher pile-up. In this thesis I present results on single modules …
ATLAS is making extensive efforts towards preparing a detector upgrade for the high luminosity operations of the LHC (HL-LHC), which will commence operation in about 10 years. The current ATLAS Inner Detector will be replaced by an all-silicon tracker (comprising an inner Pixel tracker and outer Strip tracker). The software currently used for the new silicon tracker is broadly inherited from that used for the LHC Run-1 and Run-2, but many new developments have been made to better fulfill the future detector and operation requirements. One aspect in particular which will be highlighted is the s…
The Semiconductor Tracker (SCT) is a silicon strip detector and one of the key precision tracking devices in the Inner Detector of the ATLAS experiment at CERN LHC. The completed SCT has been installed inside the ATLAS experimental cavern since 2007 and has been operational since then. Calibration data has been taken regularly and analyzed to determine the performance of the system. In this paper the current status of the SCT is reviewed, including results from data-taking periods in 2010 and 2011. We report on the operation of the detector including overviews on services, connectivity and obs…
In preparation for the High Luminosity LHC, the entire tracker detector of the CMS experiment will be exchanged as part of the Phase-2 Upgrade. The new Outer Tracker will comprise approximately 13,000 silicon sensor modules, of which 7608 are "2S modules" consisting of two parallel mounted silicon strip sensors, and 5592 are "PS modules" consisting of one pixel and one strip sensor in a single module. These modules provide tracking information to the Level 1 trigger by correlating the hit information of both sensor layers, allowing discrimination of particle tracks by their transverse momentum…
The complex system of the CMS all-silicon Tracker, with 15\,148 silicon strip and 1440 silicon pixel modules, requires sophisticated alignment procedures. In order to achieve an optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of few micrometers. The alignment of pixels modules is crucial for the analyses requiring a precise vertex reconstruction. The aligned geometry is based on the analysis of several million reconstructed tracks recorded during the commissioning of the CMS experiment, both with cosmic rays and with the fi…
An upgrade to the ATLAS silicon tracker cooling control system may require a change from C3F8 (octafluoro-propane) evaporative coolant to a blend containing 10-25% of C2F6 (hexafluoro-ethane). Such a change will reduce the evaporation temperature to assure thermal stability following radiation damage accumulated at full LHC luminosity. Central to this upgrade is a new ultrasonic instrument in which sound transit times are continuously measured in opposite directions in flowing gas at known temperature and pressure to deduce the C3F8/C2F6 flow rate and mixture composition. The instrument and it…
After the successful installation and first operation of the upgraded Inner Tracking System (ITS2), which consists of about $10\,$m$^2$ of monolithic silicon pixel sensors, ALICE is pioneering the usage of bent, wafer-scale pixel sensors for the ITS3 for LHC Run 4. Sensors larger than typical reticle sizes can be produced using the technique of stitching. At thicknesses of about $30\,μ$m, silicon is flexible enough to be bent to radii of the order of $1\,$cm. By cooling such sensors with a forced airflow, it becomes possible to construct truly cylindrical layers which consist practically only …
The DArk Matter Particle Explorer (DAMPE) is a space-borne particle detector designed to probe electrons and gamma-rays in the few GeV to 10 TeV energy range, as well as cosmic-ray proton and nuclei components between 10 GeV and 100 TeV. The silicon-tungsten tracker-converter is a crucial component of DAMPE. It allows the direction of incoming photons converting into electron-positron pairs to be estimated, and the trajectory and charge (Z) of cosmic-ray particles to be identified. It consists of 768 silicon micro-strip sensors assembled in 6 double layers with a total active area of 6.6 m$^2$…
Silicon trackers at the SLHC will suffer high radiation damage from particles produced during the collisions, which leads to high leakage currents. Reducing these currents in the sensors requires efficient cooling to -30 C. The large heat of evaporation of CO2 and the low viscosity allows for a two-phase cooling system with thin and long cooling pipes, because the small flow of liquid needed leads to negligible temperature drops. In order to reduce the material budget a system is proposed in which a large scale tracker requiring ca. 50 kW of power is powered via 1-2 mm diameter aluminum coolin…
The DArk Matter Particle Explorer (DAMPE) is one of the four satellites within Strategic Pioneer Research Program in Space Science of the Chinese Academy of Science (CAS). DAMPE can detect electrons, photons in a wide energy range (5 GeV to 10 TeV) and ions up to iron (100GeV to 100 TeV). Silicon-Tungsten Tracker (STK) is one of the four subdetectors in DAMPE, providing photon-electron conversion, track reconstruction and charge identification for ions. Ion beam test was carried out in CERN with 60GeV/u Lead primary beams. Charge reconstruction and charge resolution of STK detectors were inves…
The inner tracking system of the CMS experiment, which comprises Silicon Pixel and Silicon Strip detectors, is designed to provide a precise measurement of the momentum of charged particles and to reconstruct the primary and secondary vertices. The movements of the different substructures of the tracker detectors driven by the operating conditions during data taking, require to regularly update the detector geometry in order to accurately describe the position, orientation, and curvature of the tracker modules. The procedure in which new parameters of the tracker geometry are determined is kno…
The radiation hardness of the AToM chips of the BaBar Silicon Vertex Tracker has been investigated by means of irradiations with photons from a 60Co source and 0.9 GeV electrons. The increase in noise and the decrease in gain of the amplifier have been measured as a function of the applied capacitive load and the absorbed dose. Different beam intensities have been used to study the effect of different dose rates to the AToM radiation damage. The chip digital functionalities have been tested up to a dose of 5.5 Mrads for the 60Co photons and 9 Mrads for the 0.9 GeV electrons. In addition a pede…
Sensors fabricated from high resistivity, float zone, silicon material have been the basis of vertex detectors and trackers for the last 30 years. The areas of these devices have increased from a few square cm to $\> 200\ m^2$ for the existing CMS tracker. High Luminosity Large Hadron Collider (HL-LHC), CMS and ATLAS tracker upgrades will each require more than $200\ m^2$ of silicon and the CMS High Granularity Calorimeter (HGCAL) will require more than $600\ m^2$. The cost and complexity of assembly of these devices is related to the area of each module, which in turn is set by the size of th…
This paper presents the techniques used to monitor radiation damage in the LHCb Tracker Turicensis during the LHC Runs 1 and 2. Bulk leakage currents in the silicon sensors were monitored continuously, while the full depletion voltages of the sensors were estimated at regular intervals by performing dedicated scans of the charge collection efficiency as a function of the applied bias voltage. Predictions of the expected leakage currents and full depletion voltages are extracted from the simulated radiation profile, the luminosity delivered by the LHC, and the thermal history of the silicon sen…
A prototype module for an International Linear Collider (ILC) detector was built, installed, and tested between 2006 and 2009 at CERN and Fermilab as part of the CALICE test beam program, in order to study the possibilities of extending energy sampling behind a hadronic calorimeter and to study the possibilities of providing muon tracking. The "tail catcher/muon tracker" (TCMT) is composed of 320 extruded scintillator strips (dimensions 1000 mm x 50 mm x 5 mm) packaged in 16 one-meter square planes interleaved between steel plates. The scintillator strips were read out with wavelength shifting…
Beam test results of the Intermediate Silicon Tracker for sPHENIX
National Central University（中央大学）；Nishina Center for Accelerator-Based Science, RIKEN（理化学研究所理仁加速器科学中心）；RIKEN BNL Research Center（理化学研究所布鲁克海文研究中心）；Department of Mathematical and Physical Sciences, Nara Women’s University（奈良女子大学数理科学系）；Physics Department, Brookhaven National Laboratory（布鲁克海文国家实验室物理系）；Advanced Science Research Center, Japan Atomic Energy Agency（日本原子能研究机构先进科学研究中心）；Department of Physics, Rikkyo University（立教大学物理学系）
