Author
Y. Takahashi
Bio: Y. Takahashi is an academic researcher from University of Tsukuba. The author has contributed to research in topics: Planar & Electron. The author has an hindex of 6, co-authored 11 publications receiving 98 citations.
Topics: Planar, Electron, Semiconductor detector, Radiation damage, Pixel
Papers
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University of Tsukuba1, University of Liverpool2, University of Glasgow3, University of California, Santa Cruz4, Academy of Sciences of the Czech Republic5, University of Cambridge6, Brookhaven National Laboratory7, Lancaster University8, University of Ljubljana9, University of Geneva10, Stony Brook University11, Charles University in Prague12, University of Sheffield13, Spanish National Research Council14, University of New Mexico15, KEK16, University of Freiburg17
21 Apr 2011-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors developed n+-in-p, p-bulk and n-readout, microstrip sensors, fabricated by Hamamatsu Photonics, as a non-inverting radiation hard silicon detector for the ATLAS tracker upgrade at the super-LHC (sLHC) proposed facility.
Abstract: We are developing n+-in-p, p-bulk and n-readout, microstrip sensors, fabricated by Hamamatsu Photonics, as a non-inverting radiation hard silicon detector for the ATLAS tracker upgrade at the super-LHC (sLHC) proposed facility. The bulk radiation damage after neutron and proton irradiations is characterized with the leakage current, charge collection and full depletion voltage. The detectors should provide acceptable signal, signal-to-noise ratio exceeding 15, after the integrated luminosity of 6000 fb−1, which is twice the sLHC integrated luminosity goal.
38 citations
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21 Jan 2013-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors developed highly radiation-tolerant n + -in-p planar pixel sensors for use in the high-luminosity LHC, using various combinations of the bias structures (punch-through or polysilicon resistor), isolation structures (P-stop or p-spray), and thickness ( 320 μ m or 150 μ m ).
Abstract: We have been developing highly radiation-tolerant n + -in-p planar pixel sensors for use in the high-luminosity LHC. Novel n + -in-p structures were made using various combinations of the bias structures (punch-through or polysilicon resistor), isolation structures (p-stop or p-spray), and thicknesses ( 320 μ m or 150 μ m ). The 1-chip pixel modules with thin FE-I4 pixel sensors were evaluated using test beams, before and after 2 × 10 15 n eq / cm 2 irradiation. The full depletion voltages were estimated to be 44±10 V and 380±70 V, in the non-irradiated and the irradiated modules, respectively. A reduction of efficiency was observed in the vicinity of the four pixel corners and underneath the bias rail after the irradiation. The global efficiencies were > 99 % and > 95 % in the non-irradiated and the irradiated modules, respectively. The collected charges were uniform in the depth direction at bias voltages well above the full depletion voltages. The encapsulation of vulnerable edges with adhesive or parylene prevented HV sparking. Bump bonding with the SnAg solder bumps was performed at HPK with 150 μ m - and 320 μ m - thick sensors and chips. No disconnection of bumps was observed after 10 thermal cycles between −40 and +50 °C, with a temperature slew rate of > 70 K / min .
20 citations
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TL;DR: In this article, a built-in protection structure based on a punch through mechanism for the p-bulk n + -readout sensors under development for the HL-LHC was designed.
9 citations
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01 Dec 2011-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the effectiveness of PTP structures on n-on-p AC-coupled Silicon strip detectors using pulses from an 1064nm IR laser, which simulate beam accidents, was evaluated.
Abstract: We have tested the effectiveness of punch-through protection (PTP) structures on n-on-p AC-coupled Silicon strip detectors using pulses from an 1064 nm IR laser, which simulate beam accidents. The voltages on the strips are measured as a function of the bias voltage and compared with the results of DC I – V measurements, which are commonly used to characterize the PTP structures. We find that the PTP structures are only effective at very large currents (several mA), and clamp the strips to much larger voltages than assumed from the DC measurements. We also find that the finite resistance of the strip implant compromises the effectiveness of the PTP structures.
9 citations
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Argonne National Laboratory1, University of Iowa2, University of Bergen3, Max Planck Society4, Shinshu University5, Heidelberg University6, Northern Illinois University7, Kyushu University8, Academy of Sciences of the Czech Republic9, University of Tokyo10, University of Paris11, University of Kansas12, Russian Academy of Sciences13, University of Wuppertal14, Blaise Pascal University15, Kyungpook National University16, École Polytechnique17, University of Birmingham18, University of Tsukuba19
11 Apr 2018-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, a highly granular electromagnetic calorimeter with scintillator strip readout is developed for future linear collider experiments, and a prototype of 21.5 X 0 depth and 180×180mm2 transverse dimensions was constructed, consisting of 2160 individually read out 10×45×3mm3 scintillation strips.
Abstract: A highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 X0 depth and 180×180mm2 transverse dimensions was constructed, consisting of 2160 individually read out 10×45×3mm3 scintillator strips. This prototype was tested using electrons of 2–32 GeV at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined to be (12.5±0.1(stat.)±0.4(syst.))%∕E[GeV]⊕(1.2±0.1(stat.)−0.7+0.6(syst.))% , where the uncertainties correspond to statistical and systematic sources, respectively.
8 citations
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01 Jan 1998
561 citations
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TL;DR: A review of radiation-induced displacement damage effects in semiconductor devices is presented in this paper, with emphasis placed on silicon technology, including effects produced in silicon particle detectors, visible imaging arrays, and solar cells.
Abstract: A review of radiation-induced displacement damage effects in semiconductor devices is presented, with emphasis placed on silicon technology. The history of displacement damage studies is summarized, and damage production mechanisms are discussed. Properties of defect clusters and isolated defects are addressed. Displacement damage effects in materials and devices are considered, including effects produced in silicon particle detectors, visible imaging arrays, and solar cells. Additional topics examined include NIEL scaling, carrier concentration changes, random telegraph signals, radiation hardness assurance, and simulation methods for displacement damage. Areas needing further study are noted.
176 citations
01 Jan 2015
TL;DR: In this article, a coded-aperture imaging system for fast neutrons is presented, which consists of a 32-element array of 15 cm, 15 cm � 15 cm -15 cm 15 cm liquid scintillation detectors (EJ-309) mounted behind a 12 -12 pseudorandom coded aperture.
Abstract: This work discusses a large-scale, coded-aperture imager for fast neutrons, building off a proof-of concept instrument developed at the U.S. Naval Research Laboratory (NRL). The Space Science Division at the NRL has a heritage of developing large-scale, mobile systems, using coded-aperture imaging, for long-range γ-ray detection and localization. The fast-neutron, coded-aperture imaging instrument, designed for a mobile unit (20 ft. ISO container), consists of a 32-element array of 15 cm � 15 cm � 15 cm liquid scintillation detectors (EJ-309) mounted behind a 12 � 12 pseudorandom coded aperture. The elements of the aperture are composed of 15 cm � 15 cm � 10 cm blocks of high-density polyethylene (HDPE). The arrangement of the aperture elements produces a shadow pattern on the detector array behind the mask. By measuring of the number of neutron counts per masked and unmasked detector, and with knowledge of the mask pattern, a source image can be deconvolved to obtain a 2-d location. The number of neutrons per detector was obtained by processing the fast signal from each PMT in flash digitizing electronics. Digital pulse shape discrimination (PSD) was performed to filter out the fastneutron signal from the γ background. The prototype instrument was tested at an indoor facility at the NRL with a 1.8-μCi and 13-μCi 252Cf neutron/γ source at three standoff distances of 9, 15 and 26 m (maximum allowed in the facility) over a 15-min integration time. The imaging and detection capabilities of the instrument were tested by moving the source in half- and one-pixel increments across the image plane. We show a representative sample of the results obtained at one-pixel increments for a standoff distance of 9 m. The 1.8-μCi source was not detected at the 26-m standoff. In order to increase the sensitivity of the instrument, we reduced the fastneutron background by shielding the top, sides and back of the detector array with 10-cm-thick HDPE. This shielding configuration led to a reduction in the background by a factor of 1.7 and thus allowed for the detection and localization of the 1.8 μCi. The detection significance for each source at different standoff distances will be discussed. Published by Elsevier B.V.
115 citations
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KEK1, University of Liverpool2, University of Glasgow3, Santa Cruz Institute for Particle Physics4, Academy of Sciences of the Czech Republic5, University of Cambridge6, Brookhaven National Laboratory7, Lancaster University8, Jožef Stefan Institute9, University of Geneva10, Stony Brook University11, Charles University in Prague12, University of Sheffield13, Spanish National Research Council14, University of New Mexico15, University of Tsukuba16, University of Freiburg17, Hamamatsu Photonics18
21 Apr 2011-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors developed a highly radiation-tolerant n-in-p silicon microstrip sensor for very high radiation environments such as in the Super Large Hadron Collider.
Abstract: We have developed a novel and highly radiation-tolerant n-in-p silicon microstrip sensor for very high radiation environments such as in the Super Large Hadron Collider. The sensors are designed for a fluence of 1×1015 neq/cm2 and are fabricated from p-type, FZ, 6 in. (150 mm) wafers onto which we lay out a single 9.75 cm×9.75 cm large-area sensor and several 1 cm×1 cm miniature sensors with various n-strip isolation structures. By evaluating the sensors both pre- and post-irradiation by protons and neutrons, we find that the full depletion voltage evolves to approximately 800 V and that the n-strip isolation depends on the p+ concentration. In addition, we characterize the interstrip resistance, interstrip capacitance and the punch-through-protection (PTP) voltage. The first fabrication batch allowed us to identify the weak spots in the PTP and the stereo strip layouts. By understanding the source of the weakness, the mask was modified accordingly. After modification, the follow-up fabrication batches and the latest fabrication of about 30 main sensors and associated miniature sensors have shown good performance, with no sign of microdischarge up to 1000 V.
79 citations
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KEK1, University of Birmingham2, Brookhaven National Laboratory3, University of Cambridge4, University of Geneva5, University of Glasgow6, Hamamatsu Photonics7, Kyoto University8, Lancaster University9, University of Liverpool10, University of Ljubljana11, University of New Mexico12, Osaka University13, Charles University in Prague14, Academy of Sciences of the Czech Republic15, Queen Mary University of London16, University of California, Santa Cruz17, University of Sheffield18, Tokyo Institute of Technology19, University of Tsukuba20, Spanish National Research Council21
21 Nov 2014-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the authors have developed a novel radiation-tolerant n+in-p silicon microstrip sensor for very high radiation environments, aiming for application in the high luminosity large hadron collider.
Abstract: We have been developing a novel radiation-tolerant n+-in-p silicon microstrip sensor for very high radiation environments, aiming for application in the high luminosity large hadron collider. The sensors are fabricated in 6 in., p-type, float-zone wafers, where large-area strip sensor designs are laid out together with a number of miniature sensors. Radiation tolerance has been studied with ATLAS07 sensors and with independent structures. The ATLAS07 design was developed into new ATLAS12 designs. The ATLAS12A large-area sensor is made towards an axial strip sensor and the ATLAS12M towards a stereo strip sensor. New features to the ATLAS12 sensors are two dicing lines: standard edge space of 910 μm and slim edge space of 450 μm, a gated punch-through protection structure, and connection of orphan strips in a triangular corner of stereo strips. We report the design of the ATLAS12 layouts and initial measurements of the leakage current after dicing and the resistivity of the wafers.
49 citations